Refactor diffs

[mediawiki.git] / includes / HTMLForm.php

<?php
/**
 * HTML form generation and submission handling.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

/**
 * Object handling generic submission, CSRF protection, layout and
 * other logic for UI forms. in a reusable manner.
 *
 * In order to generate the form, the HTMLForm object takes an array
 * structure detailing the form fields available. Each element of the
 * array is a basic property-list, including the type of field, the
 * label it is to be given in the form, callbacks for validation and
 * 'filtering', and other pertinent information.
 *
 * Field types are implemented as subclasses of the generic HTMLFormField
 * object, and typically implement at least getInputHTML, which generates
 * the HTML for the input field to be placed in the table.
 *
 * You can find extensive documentation on the www.mediawiki.org wiki:
 *  - http://www.mediawiki.org/wiki/HTMLForm
 *  - http://www.mediawiki.org/wiki/HTMLForm/tutorial
 *
 * The constructor input is an associative array of $fieldname => $info,
 * where $info is an Associative Array with any of the following:
 *
 *      'class'               -- the subclass of HTMLFormField that will be used
 *                               to create the object.  *NOT* the CSS class!
 *      'type'                -- roughly translates into the <select> type attribute.
 *                               if 'class' is not specified, this is used as a map
 *                               through HTMLForm::$typeMappings to get the class name.
 *      'default'             -- default value when the form is displayed
 *      'id'                  -- HTML id attribute
 *      'cssclass'            -- CSS class
 *      'options'             -- varies according to the specific object.
 *      'label-message'       -- message key for a message to use as the label.
 *                               can be an array of msg key and then parameters to
 *                               the message.
 *      'label'               -- alternatively, a raw text message. Overridden by
 *                               label-message
 *      'help'                -- message text for a message to use as a help text.
 *      'help-message'        -- message key for a message to use as a help text.
 *                               can be an array of msg key and then parameters to
 *                               the message.
 *                               Overwrites 'help-messages' and 'help'.
 *      'help-messages'       -- array of message key. As above, each item can
 *                               be an array of msg key and then parameters.
 *                               Overwrites 'help'.
 *      'required'            -- passed through to the object, indicating that it
 *                               is a required field.
 *      'size'                -- the length of text fields
 *      'filter-callback      -- a function name to give you the chance to
 *                               massage the inputted value before it's processed.
 *                               @see HTMLForm::filter()
 *      'validation-callback' -- a function name to give you the chance
 *                               to impose extra validation on the field input.
 *                               @see HTMLForm::validate()
 *      'name'                -- By default, the 'name' attribute of the input field
 *                               is "wp{$fieldname}".  If you want a different name
 *                               (eg one without the "wp" prefix), specify it here and
 *                               it will be used without modification.
 *
 * Since 1.20, you can chain mutators to ease the form generation:
 * @par Example:
 * @code
 * $form = new HTMLForm( $someFields );
 * $form->setMethod( 'get' )
 *      ->setWrapperLegendMsg( 'message-key' )
 *      ->prepareForm()
 *      ->displayForm( '' );
 * @endcode
 * Note that you will have prepareForm and displayForm at the end. Other
 * methods call done after that would simply not be part of the form :(
 *
 * TODO: Document 'section' / 'subsection' stuff
 */
class HTMLForm extends ContextSource {

        // A mapping of 'type' inputs onto standard HTMLFormField subclasses
        public static $typeMappings = array(
                'api' => 'HTMLApiField',
                'text' => 'HTMLTextField',
                'textarea' => 'HTMLTextAreaField',
                'select' => 'HTMLSelectField',
                'radio' => 'HTMLRadioField',
                'multiselect' => 'HTMLMultiSelectField',
                'check' => 'HTMLCheckField',
                'toggle' => 'HTMLCheckField',
                'int' => 'HTMLIntField',
                'float' => 'HTMLFloatField',
                'info' => 'HTMLInfoField',
                'selectorother' => 'HTMLSelectOrOtherField',
                'selectandother' => 'HTMLSelectAndOtherField',
                'submit' => 'HTMLSubmitField',
                'hidden' => 'HTMLHiddenField',
                'edittools' => 'HTMLEditTools',
                'checkmatrix' => 'HTMLCheckMatrix',

                // HTMLTextField will output the correct type="" attribute automagically.
                // There are about four zillion other HTML5 input types, like url, but
                // we don't use those at the moment, so no point in adding all of them.
                'email' => 'HTMLTextField',
                'password' => 'HTMLTextField',
        );

        protected $mMessagePrefix;

        /** @var HTMLFormField[] */
        protected $mFlatFields;

        protected $mFieldTree;
        protected $mShowReset = false;
        protected $mShowSubmit = true;
        public $mFieldData;

        protected $mSubmitCallback;
        protected $mValidationErrorMessage;

        protected $mPre = '';
        protected $mHeader = '';
        protected $mFooter = '';
        protected $mSectionHeaders = array();
        protected $mSectionFooters = array();
        protected $mPost = '';
        protected $mId;
        protected $mTableId = '';

        protected $mSubmitID;
        protected $mSubmitName;
        protected $mSubmitText;
        protected $mSubmitTooltip;

        protected $mTitle;
        protected $mMethod = 'post';

        /**
         * Form action URL. false means we will use the URL to set Title
         * @since 1.19
         * @var bool|string
         */
        protected $mAction = false;

        protected $mUseMultipart = false;
        protected $mHiddenFields = array();
        protected $mButtons = array();

        protected $mWrapperLegend = false;

        /**
         * If true, sections that contain both fields and subsections will
         * render their subsections before their fields.
         *
         * Subclasses may set this to false to render subsections after fields
         * instead.
         */
        protected $mSubSectionBeforeFields = true;

        /**
         * Format in which to display form. For viable options,
         * @see $availableDisplayFormats
         * @var String
         */
        protected $displayFormat = 'table';

        /**
         * Available formats in which to display the form
         * @var Array
         */
        protected $availableDisplayFormats = array(
                'table',
                'div',
                'raw',
                'vform',
        );

        /**
         * Build a new HTMLForm from an array of field attributes
         * @param array $descriptor of Field constructs, as described above
         * @param $context IContextSource available since 1.18, will become compulsory in 1.18.
         *     Obviates the need to call $form->setTitle()
         * @param string $messagePrefix a prefix to go in front of default messages
         */
        public function __construct( $descriptor, /*IContextSource*/ $context = null, $messagePrefix = '' ) {
                if ( $context instanceof IContextSource ) {
                        $this->setContext( $context );
                        $this->mTitle = false; // We don't need them to set a title
                        $this->mMessagePrefix = $messagePrefix;
                } elseif ( is_null( $context ) && $messagePrefix !== '' ) {
                        $this->mMessagePrefix = $messagePrefix;
                } elseif ( is_string( $context ) && $messagePrefix === '' ) {
                        // B/C since 1.18
                        // it's actually $messagePrefix
                        $this->mMessagePrefix = $context;
                }

                // Expand out into a tree.
                $loadedDescriptor = array();
                $this->mFlatFields = array();

                foreach ( $descriptor as $fieldname => $info ) {
                        $section = isset( $info['section'] )
                                ? $info['section']
                                : '';

                        if ( isset( $info['type'] ) && $info['type'] == 'file' ) {
                                $this->mUseMultipart = true;
                        }

                        $field = self::loadInputFromParameters( $fieldname, $info );
                        // FIXME During field's construct, the parent form isn't available!
                        // could add a 'parent' name-value to $info, could add a third parameter.
                        $field->mParent = $this;

                        // vform gets too much space if empty labels generate HTML.
                        if ( $this->isVForm() ) {
                                $field->setShowEmptyLabel( false );
                        }

                        $setSection =& $loadedDescriptor;
                        if ( $section ) {
                                $sectionParts = explode( '/', $section );

                                while ( count( $sectionParts ) ) {
                                        $newName = array_shift( $sectionParts );

                                        if ( !isset( $setSection[$newName] ) ) {
                                                $setSection[$newName] = array();
                                        }

                                        $setSection =& $setSection[$newName];
                                }
                        }

                        $setSection[$fieldname] = $field;
                        $this->mFlatFields[$fieldname] = $field;
                }

                $this->mFieldTree = $loadedDescriptor;
        }

        /**
         * Set format in which to display the form
         * @param string $format the name of the format to use, must be one of
         *        $this->availableDisplayFormats
         * @throws MWException
         * @since 1.20
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function setDisplayFormat( $format ) {
                if ( !in_array( $format, $this->availableDisplayFormats ) ) {
                        throw new MWException( 'Display format must be one of ' . print_r( $this->availableDisplayFormats, true ) );
                }
                $this->displayFormat = $format;
                return $this;
        }

        /**
         * Getter for displayFormat
         * @since 1.20
         * @return String
         */
        public function getDisplayFormat() {
                return $this->displayFormat;
        }

        /**
         * Test if displayFormat is 'vform'
         * @since 1.22
         * @return Bool
         */
        public function isVForm() {
                return $this->displayFormat === 'vform';
        }

        /**
         * Add the HTMLForm-specific JavaScript, if it hasn't been
         * done already.
         * @deprecated since 1.18 load modules with ResourceLoader instead
         */
        static function addJS() {
                wfDeprecated( __METHOD__, '1.18' );
        }

        /**
         * Initialise a new Object for the field
         * @param $fieldname string
         * @param string $descriptor input Descriptor, as described above
         * @throws MWException
         * @return HTMLFormField subclass
         */
        static function loadInputFromParameters( $fieldname, $descriptor ) {
                if ( isset( $descriptor['class'] ) ) {
                        $class = $descriptor['class'];
                } elseif ( isset( $descriptor['type'] ) ) {
                        $class = self::$typeMappings[$descriptor['type']];
                        $descriptor['class'] = $class;
                } else {
                        $class = null;
                }

                if ( !$class ) {
                        throw new MWException( "Descriptor with no class: " . print_r( $descriptor, true ) );
                }

                $descriptor['fieldname'] = $fieldname;

                # TODO
                # This will throw a fatal error whenever someone try to use
                # 'class' to feed a CSS class instead of 'cssclass'. Would be
                # great to avoid the fatal error and show a nice error.
                $obj = new $class( $descriptor );

                return $obj;
        }

        /**
         * Prepare form for submission.
         *
         * @attention When doing method chaining, that should be the very last
         * method call before displayForm().
         *
         * @throws MWException
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function prepareForm() {
                # Check if we have the info we need
                if ( !$this->mTitle instanceof Title && $this->mTitle !== false ) {
                        throw new MWException( "You must call setTitle() on an HTMLForm" );
                }

                # Load data from the request.
                $this->loadData();
                return $this;
        }

        /**
         * Try submitting, with edit token check first
         * @return Status|boolean
         */
        function tryAuthorizedSubmit() {
                $result = false;

                $submit = false;
                if ( $this->getMethod() != 'post' ) {
                        $submit = true; // no session check needed
                } elseif ( $this->getRequest()->wasPosted() ) {
                        $editToken = $this->getRequest()->getVal( 'wpEditToken' );
                        if ( $this->getUser()->isLoggedIn() || $editToken != null ) {
                                // Session tokens for logged-out users have no security value.
                                // However, if the user gave one, check it in order to give a nice
                                // "session expired" error instead of "permission denied" or such.
                                $submit = $this->getUser()->matchEditToken( $editToken );
                        } else {
                                $submit = true;
                        }
                }

                if ( $submit ) {
                        $result = $this->trySubmit();
                }

                return $result;
        }

        /**
         * The here's-one-I-made-earlier option: do the submission if
         * posted, or display the form with or without funky validation
         * errors
         * @return Bool or Status whether submission was successful.
         */
        function show() {
                $this->prepareForm();

                $result = $this->tryAuthorizedSubmit();
                if ( $result === true || ( $result instanceof Status && $result->isGood() ) ) {
                        return $result;
                }

                $this->displayForm( $result );
                return false;
        }

        /**
         * Validate all the fields, and call the submission callback
         * function if everything is kosher.
         * @throws MWException
         * @return Mixed Bool true == Successful submission, Bool false
         *     == No submission attempted, anything else == Error to
         *     display.
         */
        function trySubmit() {
                # Check for validation
                foreach ( $this->mFlatFields as $fieldname => $field ) {
                        if ( !empty( $field->mParams['nodata'] ) ) {
                                continue;
                        }
                        if ( $field->validate(
                                        $this->mFieldData[$fieldname],
                                        $this->mFieldData )
                                !== true
                        ) {
                                return isset( $this->mValidationErrorMessage )
                                        ? $this->mValidationErrorMessage
                                        : array( 'htmlform-invalid-input' );
                        }
                }

                $callback = $this->mSubmitCallback;
                if ( !is_callable( $callback ) ) {
                        throw new MWException( 'HTMLForm: no submit callback provided. Use setSubmitCallback() to set one.' );
                }

                $data = $this->filterDataForSubmit( $this->mFieldData );

                $res = call_user_func( $callback, $data, $this );

                return $res;
        }

        /**
         * Set a callback to a function to do something with the form
         * once it's been successfully validated.
         * @param string $cb function name.  The function will be passed
         *       the output from HTMLForm::filterDataForSubmit, and must
         *       return Bool true on success, Bool false if no submission
         *       was attempted, or String HTML output to display on error.
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setSubmitCallback( $cb ) {
                $this->mSubmitCallback = $cb;
                return $this;
        }

        /**
         * Set a message to display on a validation error.
         * @param $msg Mixed String or Array of valid inputs to wfMessage()
         *       (so each entry can be either a String or Array)
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setValidationErrorMessage( $msg ) {
                $this->mValidationErrorMessage = $msg;
                return $this;
        }

        /**
         * Set the introductory message, overwriting any existing message.
         * @param string $msg complete text of message to display
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setIntro( $msg ) {
                $this->setPreText( $msg );
                return $this;
        }

        /**
         * Set the introductory message, overwriting any existing message.
         * @since 1.19
         * @param string $msg complete text of message to display
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setPreText( $msg ) {
                $this->mPre = $msg;
                return $this;
        }

        /**
         * Add introductory text.
         * @param string $msg complete text of message to display
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function addPreText( $msg ) {
                $this->mPre .= $msg;
                return $this;
        }

        /**
         * Add header text, inside the form.
         * @param string $msg complete text of message to display
         * @param string $section The section to add the header to
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function addHeaderText( $msg, $section = null ) {
                if ( is_null( $section ) ) {
                        $this->mHeader .= $msg;
                } else {
                        if ( !isset( $this->mSectionHeaders[$section] ) ) {
                                $this->mSectionHeaders[$section] = '';
                        }
                        $this->mSectionHeaders[$section] .= $msg;
                }
                return $this;
        }

        /**
         * Set header text, inside the form.
         * @since 1.19
         * @param string $msg complete text of message to display
         * @param $section The section to add the header to
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setHeaderText( $msg, $section = null ) {
                if ( is_null( $section ) ) {
                        $this->mHeader = $msg;
                } else {
                        $this->mSectionHeaders[$section] = $msg;
                }
                return $this;
        }

        /**
         * Add footer text, inside the form.
         * @param string $msg complete text of message to display
         * @param string $section The section to add the footer text to
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function addFooterText( $msg, $section = null ) {
                if ( is_null( $section ) ) {
                        $this->mFooter .= $msg;
                } else {
                        if ( !isset( $this->mSectionFooters[$section] ) ) {
                                $this->mSectionFooters[$section] = '';
                        }
                        $this->mSectionFooters[$section] .= $msg;
                }
                return $this;
        }

        /**
         * Set footer text, inside the form.
         * @since 1.19
         * @param string $msg complete text of message to display
         * @param string $section The section to add the footer text to
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setFooterText( $msg, $section = null ) {
                if ( is_null( $section ) ) {
                        $this->mFooter = $msg;
                } else {
                        $this->mSectionFooters[$section] = $msg;
                }
                return $this;
        }

        /**
         * Add text to the end of the display.
         * @param string $msg complete text of message to display
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function addPostText( $msg ) {
                $this->mPost .= $msg;
                return $this;
        }

        /**
         * Set text at the end of the display.
         * @param string $msg complete text of message to display
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setPostText( $msg ) {
                $this->mPost = $msg;
                return $this;
        }

        /**
         * Add a hidden field to the output
         * @param string $name field name.  This will be used exactly as entered
         * @param string $value field value
         * @param $attribs Array
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function addHiddenField( $name, $value, $attribs = array() ) {
                $attribs += array( 'name' => $name );
                $this->mHiddenFields[] = array( $value, $attribs );
                return $this;
        }

        /**
         * Add an array of hidden fields to the output
         *
         * @since 1.22
         * @param array $fields Associative array of fields to add;
         *        mapping names to their values
         * @return HTMLForm $this for chaining calls
         */
        public function addHiddenFields( array $fields ) {
                foreach ( $fields as $name => $value ) {
                        $this->mHiddenFields[] = array( $value, array( 'name' => $name ) );
                }
                return $this;
        }

        /**
         * Add a button to the form
         * @param string $name field name.
         * @param string $value field value
         * @param string $id DOM id for the button (default: null)
         * @param $attribs Array
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function addButton( $name, $value, $id = null, $attribs = null ) {
                $this->mButtons[] = compact( 'name', 'value', 'id', 'attribs' );
                return $this;
        }

        /**
         * Display the form (sending to the context's OutputPage object), with an
         * appropriate error message or stack of messages, and any validation errors, etc.
         *
         * @attention You should call prepareForm() before calling this function.
         * Moreover, when doing method chaining this should be the very last method
         * call just after prepareForm().
         *
         * @param $submitResult Mixed output from HTMLForm::trySubmit()
         * @return Nothing, should be last call
         */
        function displayForm( $submitResult ) {
                $this->getOutput()->addHTML( $this->getHTML( $submitResult ) );
        }

        /**
         * Returns the raw HTML generated by the form
         * @param $submitResult Mixed output from HTMLForm::trySubmit()
         * @return string
         */
        function getHTML( $submitResult ) {
                # For good measure (it is the default)
                $this->getOutput()->preventClickjacking();
                $this->getOutput()->addModules( 'mediawiki.htmlform' );
                if ( $this->isVForm() ) {
                        $this->getOutput()->addModuleStyles( 'mediawiki.ui' );
                        // TODO should vertical form set setWrapperLegend( false )
                        // to hide ugly fieldsets?
                }

                $html = ''
                        . $this->getErrors( $submitResult )
                        . $this->mHeader
                        . $this->getBody()
                        . $this->getHiddenFields()
                        . $this->getButtons()
                        . $this->mFooter
                ;

                $html = $this->wrapForm( $html );

                return '' . $this->mPre . $html . $this->mPost;
        }

        /**
         * Wrap the form innards in an actual "<form>" element
         * @param string $html HTML contents to wrap.
         * @return String wrapped HTML.
         */
        function wrapForm( $html ) {

                # Include a <fieldset> wrapper for style, if requested.
                if ( $this->mWrapperLegend !== false ) {
                        $html = Xml::fieldset( $this->mWrapperLegend, $html );
                }
                # Use multipart/form-data
                $encType = $this->mUseMultipart
                        ? 'multipart/form-data'
                        : 'application/x-www-form-urlencoded';
                # Attributes
                $attribs = array(
                        'action' => $this->getAction(),
                        'method' => $this->getMethod(),
                        'class' => array( 'visualClear' ),
                        'enctype' => $encType,
                );
                if ( !empty( $this->mId ) ) {
                        $attribs['id'] = $this->mId;
                }

                if ( $this->isVForm() ) {
                        array_push( $attribs['class'], 'mw-ui-vform', 'mw-ui-container' );
                }
                return Html::rawElement( 'form', $attribs, $html );
        }

        /**
         * Get the hidden fields that should go inside the form.
         * @return String HTML.
         */
        function getHiddenFields() {
                global $wgArticlePath;

                $html = '';
                if ( $this->getMethod() == 'post' ) {
                        $html .= Html::hidden( 'wpEditToken', $this->getUser()->getEditToken(), array( 'id' => 'wpEditToken' ) ) . "\n";
                        $html .= Html::hidden( 'title', $this->getTitle()->getPrefixedText() ) . "\n";
                }

                if ( strpos( $wgArticlePath, '?' ) !== false && $this->getMethod() == 'get' ) {
                        $html .= Html::hidden( 'title', $this->getTitle()->getPrefixedText() ) . "\n";
                }

                foreach ( $this->mHiddenFields as $data ) {
                        list( $value, $attribs ) = $data;
                        $html .= Html::hidden( $attribs['name'], $value, $attribs ) . "\n";
                }

                return $html;
        }

        /**
         * Get the submit and (potentially) reset buttons.
         * @return String HTML.
         */
        function getButtons() {
                $html = '<span class="mw-htmlform-submit-buttons">';

                if ( $this->mShowSubmit ) {
                        $attribs = array();

                        if ( isset( $this->mSubmitID ) ) {
                                $attribs['id'] = $this->mSubmitID;
                        }

                        if ( isset( $this->mSubmitName ) ) {
                                $attribs['name'] = $this->mSubmitName;
                        }

                        if ( isset( $this->mSubmitTooltip ) ) {
                                $attribs += Linker::tooltipAndAccesskeyAttribs( $this->mSubmitTooltip );
                        }

                        $attribs['class'] = array( 'mw-htmlform-submit' );

                        if ( $this->isVForm() ) {
                                // mw-ui-block is necessary because the buttons aren't necessarily in an 
                                // immediate child div of the vform.
                                array_push( $attribs['class'], 'mw-ui-button', 'mw-ui-big', 'mw-ui-primary', 'mw-ui-block' );
                        }

                        $html .= Xml::submitButton( $this->getSubmitText(), $attribs ) . "\n";

                        // Buttons are top-level form elements in table and div layouts,
                        // but vform wants all elements inside divs to get spaced-out block
                        // styling.
                        if ( $this->isVForm() ) {
                                $html = Html::rawElement( 'div', null, "\n$html\n" );
                        }
                }

                if ( $this->mShowReset ) {
                        $html .= Html::element(
                                'input',
                                array(
                                        'type' => 'reset',
                                        'value' => $this->msg( 'htmlform-reset' )->text()
                                )
                        ) . "\n";
                }

                foreach ( $this->mButtons as $button ) {
                        $attrs = array(
                                'type' => 'submit',
                                'name' => $button['name'],
                                'value' => $button['value']
                        );

                        if ( $button['attribs'] ) {
                                $attrs += $button['attribs'];
                        }

                        if ( isset( $button['id'] ) ) {
                                $attrs['id'] = $button['id'];
                        }

                        $html .= Html::element( 'input', $attrs );
                }

                $html .= '</span>';

                return $html;
        }

        /**
         * Get the whole body of the form.
         * @return String
         */
        function getBody() {
                return $this->displaySection( $this->mFieldTree, $this->mTableId );
        }

        /**
         * Format and display an error message stack.
         * @param $errors String|Array|Status
         * @return String
         */
        function getErrors( $errors ) {
                if ( $errors instanceof Status ) {
                        if ( $errors->isOK() ) {
                                $errorstr = '';
                        } else {
                                $errorstr = $this->getOutput()->parse( $errors->getWikiText() );
                        }
                } elseif ( is_array( $errors ) ) {
                        $errorstr = $this->formatErrors( $errors );
                } else {
                        $errorstr = $errors;
                }

                return $errorstr
                        ? Html::rawElement( 'div', array( 'class' => 'error' ), $errorstr )
                        : '';
        }

        /**
         * Format a stack of error messages into a single HTML string
         * @param array $errors of message keys/values
         * @return String HTML, a "<ul>" list of errors
         */
        public static function formatErrors( $errors ) {
                $errorstr = '';

                foreach ( $errors as $error ) {
                        if ( is_array( $error ) ) {
                                $msg = array_shift( $error );
                        } else {
                                $msg = $error;
                                $error = array();
                        }

                        $errorstr .= Html::rawElement(
                                'li',
                                array(),
                                wfMessage( $msg, $error )->parse()
                        );
                }

                $errorstr = Html::rawElement( 'ul', array(), $errorstr );

                return $errorstr;
        }

        /**
         * Set the text for the submit button
         * @param string $t plaintext.
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setSubmitText( $t ) {
                $this->mSubmitText = $t;
                return $this;
        }

        /**
         * Set the text for the submit button to a message
         * @since 1.19
         * @param string $msg message key
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function setSubmitTextMsg( $msg ) {
                $this->setSubmitText( $this->msg( $msg )->text() );
                return $this;
        }

        /**
         * Get the text for the submit button, either customised or a default.
         * @return string
         */
        function getSubmitText() {
                return $this->mSubmitText
                        ? $this->mSubmitText
                        : $this->msg( 'htmlform-submit' )->text();
        }

        /**
         * @param string $name Submit button name
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function setSubmitName( $name ) {
                $this->mSubmitName = $name;
                return $this;
        }

        /**
         * @param string $name Tooltip for the submit button
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function setSubmitTooltip( $name ) {
                $this->mSubmitTooltip = $name;
                return $this;
        }

        /**
         * Set the id for the submit button.
         * @param $t String.
         * @todo FIXME: Integrity of $t is *not* validated
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setSubmitID( $t ) {
                $this->mSubmitID = $t;
                return $this;
        }

        /**
         * Stop a default submit button being shown for this form. This implies that an
         * alternate submit method must be provided manually.
         *
         * @since 1.22
         *
         * @param bool $suppressSubmit Set to false to re-enable the button again
         *
         * @return HTMLForm $this for chaining calls
         */
        function suppressDefaultSubmit( $suppressSubmit = true ) {
                $this->mShowSubmit = !$suppressSubmit;
                return $this;
        }

        /**
         * Set the id of the \<table\> or outermost \<div\> element.
         *
         * @since 1.22
         * @param string $id new value of the id attribute, or "" to remove
         * @return HTMLForm $this for chaining calls
         */
        public function setTableId( $id ) {
                $this->mTableId = $id;
                return $this;
        }

        /**
         * @param string $id DOM id for the form
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function setId( $id ) {
                $this->mId = $id;
                return $this;
        }

        /**
         * Prompt the whole form to be wrapped in a "<fieldset>", with
         * this text as its "<legend>" element.
         * @param string|false $legend HTML to go inside the "<legend>" element, or
         * false for no <legend>
         *       Will be escaped
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function setWrapperLegend( $legend ) {
                $this->mWrapperLegend = $legend;
                return $this;
        }

        /**
         * Prompt the whole form to be wrapped in a "<fieldset>", with
         * this message as its "<legend>" element.
         * @since 1.19
         * @param string $msg message key
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function setWrapperLegendMsg( $msg ) {
                $this->setWrapperLegend( $this->msg( $msg )->text() );
                return $this;
        }

        /**
         * Set the prefix for various default messages
         * @todo currently only used for the "<fieldset>" legend on forms
         * with multiple sections; should be used elsewhere?
         * @param $p String
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setMessagePrefix( $p ) {
                $this->mMessagePrefix = $p;
                return $this;
        }

        /**
         * Set the title for form submission
         * @param $t Title of page the form is on/should be posted to
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function setTitle( $t ) {
                $this->mTitle = $t;
                return $this;
        }

        /**
         * Get the title
         * @return Title
         */
        function getTitle() {
                return $this->mTitle === false
                        ? $this->getContext()->getTitle()
                        : $this->mTitle;
        }

        /**
         * Set the method used to submit the form
         * @param $method String
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function setMethod( $method = 'post' ) {
                $this->mMethod = $method;
                return $this;
        }

        public function getMethod() {
                return $this->mMethod;
        }

        /**
         * @todo Document
         * @param array[]|HTMLFormField[] $fields array of fields (either arrays or objects)
         * @param string $sectionName ID attribute of the "<table>" tag for this section, ignored if empty
         * @param string $fieldsetIDPrefix ID prefix for the "<fieldset>" tag of each subsection, ignored if empty
         * @param boolean &$hasUserVisibleFields Whether the section had user-visible fields
         * @return String
         */
        public function displaySection( $fields, $sectionName = '', $fieldsetIDPrefix = '', &$hasUserVisibleFields = false ) {
                $displayFormat = $this->getDisplayFormat();

                $html = '';
                $subsectionHtml = '';
                $hasLabel = false;

                switch( $displayFormat ) {
                        case 'table':
                                $getFieldHtmlMethod = 'getTableRow';
                                break;
                        case 'vform':
                                // Close enough to a div.
                                $getFieldHtmlMethod = 'getDiv';
                                break;
                        default:
                                $getFieldHtmlMethod = 'get' . ucfirst( $displayFormat );
                }

                foreach ( $fields as $key => $value ) {
                        if ( $value instanceof HTMLFormField ) {
                                $v = empty( $value->mParams['nodata'] )
                                        ? $this->mFieldData[$key]
                                        : $value->getDefault();
                                $html .= $value->$getFieldHtmlMethod( $v );

                                $labelValue = trim( $value->getLabel() );
                                if ( $labelValue != '&#160;' && $labelValue !== '' ) {
                                        $hasLabel = true;
                                }

                                if ( get_class( $value ) !== 'HTMLHiddenField' &&
                                                get_class( $value ) !== 'HTMLApiField' ) {
                                        $hasUserVisibleFields = true;
                                }
                        } elseif ( is_array( $value ) ) {
                                $subsectionHasVisibleFields = false;
                                $section = $this->displaySection( $value, "mw-htmlform-$key", "$fieldsetIDPrefix$key-", $subsectionHasVisibleFields );
                                $legend = null;

                                if ( $subsectionHasVisibleFields === true ) {
                                        // Display the section with various niceties.
                                        $hasUserVisibleFields = true;

                                        $legend = $this->getLegend( $key );

                                        if ( isset( $this->mSectionHeaders[$key] ) ) {
                                                $section = $this->mSectionHeaders[$key] . $section;
                                        }
                                        if ( isset( $this->mSectionFooters[$key] ) ) {
                                                $section .= $this->mSectionFooters[$key];
                                        }

                                        $attributes = array();
                                        if ( $fieldsetIDPrefix ) {
                                                $attributes['id'] = Sanitizer::escapeId( "$fieldsetIDPrefix$key" );
                                        }
                                        $subsectionHtml .= Xml::fieldset( $legend, $section, $attributes ) . "\n";
                                } else {
                                        // Just return the inputs, nothing fancy.
                                        $subsectionHtml .= $section;
                                }
                        }
                }

                if ( $displayFormat !== 'raw' ) {
                        $classes = array();

                        if ( !$hasLabel ) { // Avoid strange spacing when no labels exist
                                $classes[] = 'mw-htmlform-nolabel';
                        }

                        $attribs = array(
                                'class' => implode( ' ', $classes ),
                        );

                        if ( $sectionName ) {
                                $attribs['id'] = Sanitizer::escapeId( $sectionName );
                        }

                        if ( $displayFormat === 'table' ) {
                                $html = Html::rawElement( 'table', $attribs,
                                        Html::rawElement( 'tbody', array(), "\n$html\n" ) ) . "\n";
                        } elseif ( $displayFormat === 'div' || $displayFormat === 'vform' ) {
                                $html = Html::rawElement( 'div', $attribs, "\n$html\n" );
                        }
                }

                if ( $this->mSubSectionBeforeFields ) {
                        return $subsectionHtml . "\n" . $html;
                } else {
                        return $html . "\n" . $subsectionHtml;
                }
        }

        /**
         * Construct the form fields from the Descriptor array
         */
        function loadData() {
                $fieldData = array();

                foreach ( $this->mFlatFields as $fieldname => $field ) {
                        if ( !empty( $field->mParams['nodata'] ) ) {
                                continue;
                        } elseif ( !empty( $field->mParams['disabled'] ) ) {
                                $fieldData[$fieldname] = $field->getDefault();
                        } else {
                                $fieldData[$fieldname] = $field->loadDataFromRequest( $this->getRequest() );
                        }
                }

                # Filter data.
                foreach ( $fieldData as $name => &$value ) {
                        $field = $this->mFlatFields[$name];
                        $value = $field->filter( $value, $this->mFlatFields );
                }

                $this->mFieldData = $fieldData;
        }

        /**
         * Stop a reset button being shown for this form
         * @param bool $suppressReset set to false to re-enable the
         *       button again
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        function suppressReset( $suppressReset = true ) {
                $this->mShowReset = !$suppressReset;
                return $this;
        }

        /**
         * Overload this if you want to apply special filtration routines
         * to the form as a whole, after it's submitted but before it's
         * processed.
         * @param $data
         * @return
         */
        function filterDataForSubmit( $data ) {
                return $data;
        }

        /**
         * Get a string to go in the "<legend>" of a section fieldset.
         * Override this if you want something more complicated.
         * @param $key String
         * @return String
         */
        public function getLegend( $key ) {
                return $this->msg( "{$this->mMessagePrefix}-$key" )->text();
        }

        /**
         * Set the value for the action attribute of the form.
         * When set to false (which is the default state), the set title is used.
         *
         * @since 1.19
         *
         * @param string|bool $action
         * @return HTMLForm $this for chaining calls (since 1.20)
         */
        public function setAction( $action ) {
                $this->mAction = $action;
                return $this;
        }

        /**
         * Get the value for the action attribute of the form.
         *
         * @since 1.22
         *
         * @return string
         */
        public function getAction() {
                global $wgScript, $wgArticlePath;

                // If an action is alredy provided, return it
                if ( $this->mAction !== false ) {
                        return $this->mAction;
                }

                // Check whether we are in GET mode and $wgArticlePath contains a "?"
                // meaning that getLocalURL() would return something like "index.php?title=...".
                // As browser remove the query string before submitting GET forms,
                // it means that the title would be lost. In such case use $wgScript instead
                // and put title in an hidden field (see getHiddenFields()).
                if ( strpos( $wgArticlePath, '?' ) !== false && $this->getMethod() === 'get' ) {
                        return $wgScript;
                }

                return $this->getTitle()->getLocalURL();
        }
}

/**
 * The parent class to generate form fields.  Any field type should
 * be a subclass of this.
 */
abstract class HTMLFormField {

        protected $mValidationCallback;
        protected $mFilterCallback;
        protected $mName;
        public $mParams;
        protected $mLabel;      # String label.  Set on construction
        protected $mID;
        protected $mClass = '';
        protected $mDefault;

        /**
         * @var bool If true will generate an empty div element with no label
         * @since 1.22
         */
        protected $mShowEmptyLabels = true;

        /**
         * @var HTMLForm
         */
        public $mParent;

        /**
         * This function must be implemented to return the HTML to generate
         * the input object itself.  It should not implement the surrounding
         * table cells/rows, or labels/help messages.
         * @param string $value the value to set the input to; eg a default
         *       text for a text input.
         * @return String valid HTML.
         */
        abstract function getInputHTML( $value );

        /**
         * Get a translated interface message
         *
         * This is a wrapper around $this->mParent->msg() if $this->mParent is set
         * and wfMessage() otherwise.
         *
         * Parameters are the same as wfMessage().
         *
         * @return Message object
         */
        function msg() {
                $args = func_get_args();

                if ( $this->mParent ) {
                        $callback = array( $this->mParent, 'msg' );
                } else {
                        $callback = 'wfMessage';
                }

                return call_user_func_array( $callback, $args );
        }

        /**
         * Override this function to add specific validation checks on the
         * field input.  Don't forget to call parent::validate() to ensure
         * that the user-defined callback mValidationCallback is still run
         * @param string $value the value the field was submitted with
         * @param array $alldata the data collected from the form
         * @return Mixed Bool true on success, or String error to display.
         */
        function validate( $value, $alldata ) {
                if ( isset( $this->mParams['required'] ) && $this->mParams['required'] !== false && $value === '' ) {
                        return $this->msg( 'htmlform-required' )->parse();
                }

                if ( isset( $this->mValidationCallback ) ) {
                        return call_user_func( $this->mValidationCallback, $value, $alldata, $this->mParent );
                }

                return true;
        }

        function filter( $value, $alldata ) {
                if ( isset( $this->mFilterCallback ) ) {
                        $value = call_user_func( $this->mFilterCallback, $value, $alldata, $this->mParent );
                }

                return $value;
        }

        /**
         * Should this field have a label, or is there no input element with the
         * appropriate id for the label to point to?
         *
         * @return bool True to output a label, false to suppress
         */
        protected function needsLabel() {
                return true;
        }

        /**
         * Tell the field whether to generate a separate label element if its label
         * is blank.
         *
         * @since 1.22
         * @param bool $show Set to false to not generate a label.
         * @return void
         */
        public function setShowEmptyLabel( $show ) {
                $this->mShowEmptyLabels = $show;
        }

        /**
         * Get the value that this input has been set to from a posted form,
         * or the input's default value if it has not been set.
         * @param $request WebRequest
         * @return String the value
         */
        function loadDataFromRequest( $request ) {
                if ( $request->getCheck( $this->mName ) ) {
                        return $request->getText( $this->mName );
                } else {
                        return $this->getDefault();
                }
        }

        /**
         * Initialise the object
         * @param array $params Associative Array. See HTMLForm doc for syntax.
         *
         * @since 1.22 The 'label' attribute no longer accepts raw HTML, use 'label-raw' instead
         * @throws MWException
         */
        function __construct( $params ) {
                $this->mParams = $params;

                # Generate the label from a message, if possible
                if ( isset( $params['label-message'] ) ) {
                        $msgInfo = $params['label-message'];

                        if ( is_array( $msgInfo ) ) {
                                $msg = array_shift( $msgInfo );
                        } else {
                                $msg = $msgInfo;
                                $msgInfo = array();
                        }

                        $this->mLabel = wfMessage( $msg, $msgInfo )->parse();
                } elseif ( isset( $params['label'] ) ) {
                        if ( $params['label'] === '&#160;' ) {
                                // Apparently some things set &nbsp directly and in an odd format
                                $this->mLabel = '&#160;';
                        } else {
                                $this->mLabel = htmlspecialchars( $params['label'] );
                        }
                } elseif ( isset( $params['label-raw'] ) ) {
                        $this->mLabel = $params['label-raw'];
                }

                $this->mName = "wp{$params['fieldname']}";
                if ( isset( $params['name'] ) ) {
                        $this->mName = $params['name'];
                }

                $validName = Sanitizer::escapeId( $this->mName );
                if ( $this->mName != $validName && !isset( $params['nodata'] ) ) {
                        throw new MWException( "Invalid name '{$this->mName}' passed to " . __METHOD__ );
                }

                $this->mID = "mw-input-{$this->mName}";

                if ( isset( $params['default'] ) ) {
                        $this->mDefault = $params['default'];
                }

                if ( isset( $params['id'] ) ) {
                        $id = $params['id'];
                        $validId = Sanitizer::escapeId( $id );

                        if ( $id != $validId ) {
                                throw new MWException( "Invalid id '$id' passed to " . __METHOD__ );
                        }

                        $this->mID = $id;
                }

                if ( isset( $params['cssclass'] ) ) {
                        $this->mClass = $params['cssclass'];
                }

                if ( isset( $params['validation-callback'] ) ) {
                        $this->mValidationCallback = $params['validation-callback'];
                }

                if ( isset( $params['filter-callback'] ) ) {
                        $this->mFilterCallback = $params['filter-callback'];
                }

                if ( isset( $params['flatlist'] ) ) {
                        $this->mClass .= ' mw-htmlform-flatlist';
                }

                if ( isset( $params['hidelabel'] ) ) {
                        $this->mShowEmptyLabels = false;
                }
        }

        /**
         * Get the complete table row for the input, including help text,
         * labels, and whatever.
         * @param string $value the value to set the input to.
         * @return String complete HTML table row.
         */
        function getTableRow( $value ) {
                list( $errors, $errorClass ) = $this->getErrorsAndErrorClass( $value );
                $inputHtml = $this->getInputHTML( $value );
                $fieldType = get_class( $this );
                $helptext = $this->getHelpTextHtmlTable( $this->getHelpText() );
                $cellAttributes = array();

                if ( !empty( $this->mParams['vertical-label'] ) ) {
                        $cellAttributes['colspan'] = 2;
                        $verticalLabel = true;
                } else {
                        $verticalLabel = false;
                }

                $label = $this->getLabelHtml( $cellAttributes );

                $field = Html::rawElement(
                        'td',
                        array( 'class' => 'mw-input' ) + $cellAttributes,
                        $inputHtml . "\n$errors"
                );

                if ( $verticalLabel ) {
                        $html = Html::rawElement( 'tr',
                                array( 'class' => 'mw-htmlform-vertical-label' ), $label );
                        $html .= Html::rawElement( 'tr',
                                array( 'class' => "mw-htmlform-field-$fieldType {$this->mClass} $errorClass" ),
                                $field );
                } else {
                        $html = Html::rawElement( 'tr',
                                array( 'class' => "mw-htmlform-field-$fieldType {$this->mClass} $errorClass" ),
                                $label . $field );
                }

                return $html . $helptext;
        }

        /**
         * Get the complete div for the input, including help text,
         * labels, and whatever.
         * @since 1.20
         * @param string $value the value to set the input to.
         * @return String complete HTML table row.
         */
        public function getDiv( $value ) {
                list( $errors, $errorClass ) = $this->getErrorsAndErrorClass( $value );
                $inputHtml = $this->getInputHTML( $value );
                $fieldType = get_class( $this );
                $helptext = $this->getHelpTextHtmlDiv( $this->getHelpText() );
                $cellAttributes = array();
                $label = $this->getLabelHtml( $cellAttributes );

                $outerDivClass = array(
                        'mw-input',
                        'mw-htmlform-nolabel' => ( $label === '' )
                );

                $field = Html::rawElement(
                        'div',
                        array( 'class' => $outerDivClass ) + $cellAttributes,
                        $inputHtml . "\n$errors"
                );
                $divCssClasses = array( "mw-htmlform-field-$fieldType", $this->mClass, $errorClass );
                if ( $this->mParent->isVForm() ) {
                        $divCssClasses[] = 'mw-ui-vform-div';
                }
                $html = Html::rawElement( 'div',
                        array( 'class' => $divCssClasses ),
                        $label . $field );
                $html .= $helptext;
                return $html;
        }

        /**
         * Get the complete raw fields for the input, including help text,
         * labels, and whatever.
         * @since 1.20
         * @param string $value the value to set the input to.
         * @return String complete HTML table row.
         */
        public function getRaw( $value ) {
                list( $errors, ) = $this->getErrorsAndErrorClass( $value );
                $inputHtml = $this->getInputHTML( $value );
                $helptext = $this->getHelpTextHtmlRaw( $this->getHelpText() );
                $cellAttributes = array();
                $label = $this->getLabelHtml( $cellAttributes );

                $html = "\n$errors";
                $html .= $label;
                $html .= $inputHtml;
                $html .= $helptext;
                return $html;
        }

        /**
         * Generate help text HTML in table format
         * @since 1.20
         * @param $helptext String|null
         * @return String
         */
        public function getHelpTextHtmlTable( $helptext ) {
                if ( is_null( $helptext ) ) {
                        return '';
                }

                $row = Html::rawElement(
                        'td',
                        array( 'colspan' => 2, 'class' => 'htmlform-tip' ),
                        $helptext
                );
                $row = Html::rawElement( 'tr', array(), $row );
                return $row;
        }

        /**
         * Generate help text HTML in div format
         * @since 1.20
         * @param $helptext String|null
         * @return String
         */
        public function getHelpTextHtmlDiv( $helptext ) {
                if ( is_null( $helptext ) ) {
                        return '';
                }

                $div = Html::rawElement( 'div', array( 'class' => 'htmlform-tip' ), $helptext );
                return $div;
        }

        /**
         * Generate help text HTML formatted for raw output
         * @since 1.20
         * @param $helptext String|null
         * @return String
         */
        public function getHelpTextHtmlRaw( $helptext ) {
                return $this->getHelpTextHtmlDiv( $helptext );
        }

        /**
         * Determine the help text to display
         * @since 1.20
         * @return String
         */
        public function getHelpText() {
                $helptext = null;

                if ( isset( $this->mParams['help-message'] ) ) {
                        $this->mParams['help-messages'] = array( $this->mParams['help-message'] );
                }

                if ( isset( $this->mParams['help-messages'] ) ) {
                        foreach ( $this->mParams['help-messages'] as $name ) {
                                $helpMessage = (array)$name;
                                $msg = $this->msg( array_shift( $helpMessage ), $helpMessage );

                                if ( $msg->exists() ) {
                                        if ( is_null( $helptext ) ) {
                                                $helptext = '';
                                        } else {
                                                $helptext .= $this->msg( 'word-separator' )->escaped(); // some space
                                        }
                                        $helptext .= $msg->parse(); // Append message
                                }
                        }
                }
                elseif ( isset( $this->mParams['help'] ) ) {
                        $helptext = $this->mParams['help'];
                }
                return $helptext;
        }

        /**
         * Determine form errors to display and their classes
         * @since 1.20
         * @param string $value the value of the input
         * @return Array
         */
        public function getErrorsAndErrorClass( $value ) {
                $errors = $this->validate( $value, $this->mParent->mFieldData );

                if ( $errors === true || ( !$this->mParent->getRequest()->wasPosted() && ( $this->mParent->getMethod() == 'post' ) ) ) {
                        $errors = '';
                        $errorClass = '';
                } else {
                        $errors = self::formatErrors( $errors );
                        $errorClass = 'mw-htmlform-invalid-input';
                }
                return array( $errors, $errorClass );
        }

        function getLabel() {
                return is_null( $this->mLabel ) ? '' : $this->mLabel;
        }

        function getLabelHtml( $cellAttributes = array() ) {
                # Don't output a for= attribute for labels with no associated input.
                # Kind of hacky here, possibly we don't want these to be <label>s at all.
                $for = array();

                if ( $this->needsLabel() ) {
                        $for['for'] = $this->mID;
                }

                $labelValue = trim( $this->getLabel() );
                $hasLabel = false;
                if ( $labelValue !== '&#160;' && $labelValue !== '' ) {
                        $hasLabel = true;
                }

                $displayFormat = $this->mParent->getDisplayFormat();
                $html = '';

                if ( $displayFormat === 'table' ) {
                        $html = Html::rawElement( 'td', array( 'class' => 'mw-label' ) + $cellAttributes,
                                Html::rawElement( 'label', $for, $labelValue )
                        );
                } elseif ( $hasLabel || $this->mShowEmptyLabels ) {
                        if ( $displayFormat === 'div' ) {
                                $html = Html::rawElement(
                                        'div',
                                        array( 'class' => 'mw-label' ) + $cellAttributes,
                                        Html::rawElement( 'label', $for, $labelValue )
                                );
                        } else {
                                $html = Html::rawElement( 'label', $for, $labelValue );
                        }
                }

                return $html;
        }

        function getDefault() {
                if ( isset( $this->mDefault ) ) {
                        return $this->mDefault;
                } else {
                        return null;
                }
        }

        /**
         * Returns the attributes required for the tooltip and accesskey.
         *
         * @return array Attributes
         */
        public function getTooltipAndAccessKey() {
                if ( empty( $this->mParams['tooltip'] ) ) {
                        return array();
                }
                return Linker::tooltipAndAccesskeyAttribs( $this->mParams['tooltip'] );
        }

        /**
         * flatten an array of options to a single array, for instance,
         * a set of "<options>" inside "<optgroups>".
         * @param array $options Associative Array with values either Strings
         *       or Arrays
         * @return Array flattened input
         */
        public static function flattenOptions( $options ) {
                $flatOpts = array();

                foreach ( $options as $value ) {
                        if ( is_array( $value ) ) {
                                $flatOpts = array_merge( $flatOpts, self::flattenOptions( $value ) );
                        } else {
                                $flatOpts[] = $value;
                        }
                }

                return $flatOpts;
        }

        /**
         * Formats one or more errors as accepted by field validation-callback.
         * @param $errors String|Message|Array of strings or Message instances
         * @return String html
         * @since 1.18
         */
        protected static function formatErrors( $errors ) {
                if ( is_array( $errors ) && count( $errors ) === 1 ) {
                        $errors = array_shift( $errors );
                }

                if ( is_array( $errors ) ) {
                        $lines = array();
                        foreach ( $errors as $error ) {
                                if ( $error instanceof Message ) {
                                        $lines[] = Html::rawElement( 'li', array(), $error->parse() );
                                } else {
                                        $lines[] = Html::rawElement( 'li', array(), $error );
                                }
                        }
                        return Html::rawElement( 'ul', array( 'class' => 'error' ), implode( "\n", $lines ) );
                } else {
                        if ( $errors instanceof Message ) {
                                $errors = $errors->parse();
                        }
                        return Html::rawElement( 'span', array( 'class' => 'error' ), $errors );
                }
        }
}

class HTMLTextField extends HTMLFormField {
        function getSize() {
                return isset( $this->mParams['size'] )
                        ? $this->mParams['size']
                        : 45;
        }

        function getInputHTML( $value ) {
                $attribs = array(
                        'id' => $this->mID,
                        'name' => $this->mName,
                        'size' => $this->getSize(),
                        'value' => $value,
                ) + $this->getTooltipAndAccessKey();

                if ( $this->mClass !== '' ) {
                        $attribs['class'] = $this->mClass;
                }

                if ( !empty( $this->mParams['disabled'] ) ) {
                        $attribs['disabled'] = 'disabled';
                }

                # TODO: Enforce pattern, step, required, readonly on the server side as
                # well
                $allowedParams = array( 'min', 'max', 'pattern', 'title', 'step',
                        'placeholder', 'list', 'maxlength' );
                foreach ( $allowedParams as $param ) {
                        if ( isset( $this->mParams[$param] ) ) {
                                $attribs[$param] = $this->mParams[$param];
                        }
                }

                foreach ( array( 'required', 'autofocus', 'multiple', 'readonly' ) as $param ) {
                        if ( isset( $this->mParams[$param] ) ) {
                                $attribs[$param] = '';
                        }
                }

                # Implement tiny differences between some field variants
                # here, rather than creating a new class for each one which
                # is essentially just a clone of this one.
                if ( isset( $this->mParams['type'] ) ) {
                        switch ( $this->mParams['type'] ) {
                                case 'email':
                                        $attribs['type'] = 'email';
                                        break;
                                case 'int':
                                        $attribs['type'] = 'number';
                                        break;
                                case 'float':
                                        $attribs['type'] = 'number';
                                        $attribs['step'] = 'any';
                                        break;
                                # Pass through
                                case 'password':
                                case 'file':
                                        $attribs['type'] = $this->mParams['type'];
                                        break;
                        }
                }

                return Html::element( 'input', $attribs );
        }
}
class HTMLTextAreaField extends HTMLFormField {
        const DEFAULT_COLS = 80;
        const DEFAULT_ROWS = 25;

        function getCols() {
                return isset( $this->mParams['cols'] )
                        ? $this->mParams['cols']
                        : static::DEFAULT_COLS;
        }

        function getRows() {
                return isset( $this->mParams['rows'] )
                        ? $this->mParams['rows']
                        : static::DEFAULT_ROWS;
        }

        function getInputHTML( $value ) {
                $attribs = array(
                        'id' => $this->mID,
                        'name' => $this->mName,
                        'cols' => $this->getCols(),
                        'rows' => $this->getRows(),
                ) + $this->getTooltipAndAccessKey();

                if ( $this->mClass !== '' ) {
                        $attribs['class'] = $this->mClass;
                }

                if ( !empty( $this->mParams['disabled'] ) ) {
                        $attribs['disabled'] = 'disabled';
                }

                if ( !empty( $this->mParams['readonly'] ) ) {
                        $attribs['readonly'] = 'readonly';
                }

                if ( isset( $this->mParams['placeholder'] ) ) {
                        $attribs['placeholder'] = $this->mParams['placeholder'];
                }

                foreach ( array( 'required', 'autofocus' ) as $param ) {
                        if ( isset( $this->mParams[$param] ) ) {
                                $attribs[$param] = '';
                        }
                }

                return Html::element( 'textarea', $attribs, $value );
        }
}

/**
 * A field that will contain a numeric value
 */
class HTMLFloatField extends HTMLTextField {
        function getSize() {
                return isset( $this->mParams['size'] )
                        ? $this->mParams['size']
                        : 20;
        }

        function validate( $value, $alldata ) {
                $p = parent::validate( $value, $alldata );

                if ( $p !== true ) {
                        return $p;
                }

                $value = trim( $value );

                # http://dev.w3.org/html5/spec/common-microsyntaxes.html#real-numbers
                # with the addition that a leading '+' sign is ok.
                if ( !preg_match( '/^((\+|\-)?\d+(\.\d+)?(E(\+|\-)?\d+)?)?$/i', $value ) ) {
                        return $this->msg( 'htmlform-float-invalid' )->parseAsBlock();
                }

                # The "int" part of these message names is rather confusing.
                # They make equal sense for all numbers.
                if ( isset( $this->mParams['min'] ) ) {
                        $min = $this->mParams['min'];

                        if ( $min > $value ) {
                                return $this->msg( 'htmlform-int-toolow', $min )->parseAsBlock();
                        }
                }

                if ( isset( $this->mParams['max'] ) ) {
                        $max = $this->mParams['max'];

                        if ( $max < $value ) {
                                return $this->msg( 'htmlform-int-toohigh', $max )->parseAsBlock();
                        }
                }

                return true;
        }
}

/**
 * A field that must contain a number
 */
class HTMLIntField extends HTMLFloatField {
        function validate( $value, $alldata ) {
                $p = parent::validate( $value, $alldata );

                if ( $p !== true ) {
                        return $p;
                }

                # http://dev.w3.org/html5/spec/common-microsyntaxes.html#signed-integers
                # with the addition that a leading '+' sign is ok. Note that leading zeros
                # are fine, and will be left in the input, which is useful for things like
                # phone numbers when you know that they are integers (the HTML5 type=tel
                # input does not require its value to be numeric).  If you want a tidier
                # value to, eg, save in the DB, clean it up with intval().
                if ( !preg_match( '/^((\+|\-)?\d+)?$/', trim( $value ) )
                ) {
                        return $this->msg( 'htmlform-int-invalid' )->parseAsBlock();
                }

                return true;
        }
}

/**
 * A checkbox field
 */
class HTMLCheckField extends HTMLFormField {
        function getInputHTML( $value ) {
                if ( !empty( $this->mParams['invert'] ) ) {
                        $value = !$value;
                }

                $attr = $this->getTooltipAndAccessKey();
                $attr['id'] = $this->mID;

                if ( !empty( $this->mParams['disabled'] ) ) {
                        $attr['disabled'] = 'disabled';
                }

                if ( $this->mClass !== '' ) {
                        $attr['class'] = $this->mClass;
                }

                if ( $this->mParent->isVForm() ) {
                        // Nest checkbox inside label.
                        return Html::rawElement(
                                        'label',
                                        array(
                                                'class' => 'mw-ui-checkbox-label'
                                        ),
                                        Xml::check(
                                                $this->mName,
                                                $value,
                                                $attr
                                        ) .
                                        // Html:rawElement doesn't escape contents.
                                        htmlspecialchars( $this->mLabel )
                                );
                } else {
                        return Xml::check( $this->mName, $value, $attr ) . '&#160;' .
                                Html::rawElement( 'label', array( 'for' => $this->mID ), $this->mLabel );
                }
        }

        /**
         * For a checkbox, the label goes on the right hand side, and is
         * added in getInputHTML(), rather than HTMLFormField::getRow()
         * @return String
         */
        function getLabel() {
                return '&#160;';
        }

        /**
         * checkboxes don't need a label.
         */
        protected function needsLabel() {
                return false;
        }

        /**
         * @param  $request WebRequest
         * @return String
         */
        function loadDataFromRequest( $request ) {
                $invert = false;
                if ( isset( $this->mParams['invert'] ) && $this->mParams['invert'] ) {
                        $invert = true;
                }

                // GetCheck won't work like we want for checks.
                // Fetch the value in either one of the two following case:
                // - we have a valid token (form got posted or GET forged by the user)
                // - checkbox name has a value (false or true), ie is not null
                if ( $request->getCheck( 'wpEditToken' ) || $request->getVal( $this->mName ) !== null ) {
                        // XOR has the following truth table, which is what we want
                        // INVERT VALUE | OUTPUT
                        // true   true  | false
                        // false  true  | true
                        // false  false | false
                        // true   false | true
                        return $request->getBool( $this->mName ) xor $invert;
                } else {
                        return $this->getDefault();
                }
        }
}

/**
 * A checkbox matrix
 * Operates similarly to HTMLMultiSelectField, but instead of using an array of
 * options, uses an array of rows and an array of columns to dynamically
 * construct a matrix of options. The tags used to identify a particular cell
 * are of the form "columnName-rowName"
 *
 * Options:
 *   - columns
 *     - Required list of columns in the matrix.
 *   - rows
 *     - Required list of rows in the matrix.
 *   - force-options-on
 *     - Accepts array of column-row tags to be displayed as enabled but unavailable to change
 *   - force-options-off
 *     - Accepts array of column-row tags to be displayed as disabled but unavailable to change.
 *   - tooltips
 *     - Optional array mapping row label to tooltip content
 *   - tooltip-class
 *     - Optional CSS class used on tooltip container span. Defaults to mw-icon-question.
 */
class HTMLCheckMatrix extends HTMLFormField implements HTMLNestedFilterable {

        static private $requiredParams = array(
                // Required by underlying HTMLFormField
                'fieldname',
                // Required by HTMLCheckMatrix
                'rows', 'columns'
        );

        public function __construct( $params ) {
                $missing = array_diff( self::$requiredParams, array_keys( $params ) );
                if ( $missing ) {
                        throw new HTMLFormFieldRequiredOptionsException( $this, $missing );
                }
                parent::__construct( $params );
        }

        function validate( $value, $alldata ) {
                $rows = $this->mParams['rows'];
                $columns = $this->mParams['columns'];

                // Make sure user-defined validation callback is run
                $p = parent::validate( $value, $alldata );
                if ( $p !== true ) {
                        return $p;
                }

                // Make sure submitted value is an array
                if ( !is_array( $value ) ) {
                        return false;
                }

                // If all options are valid, array_intersect of the valid options
                // and the provided options will return the provided options.
                $validOptions = array();
                foreach ( $rows as $rowTag ) {
                        foreach ( $columns as $columnTag ) {
                                $validOptions[] = $columnTag . '-' . $rowTag;
                        }
                }
                $validValues = array_intersect( $value, $validOptions );
                if ( count( $validValues ) == count( $value ) ) {
                        return true;
                } else {
                        return $this->msg( 'htmlform-select-badoption' )->parse();
                }
        }

        /**
         * Build a table containing a matrix of checkbox options.
         * The value of each option is a combination of the row tag and column tag.
         * mParams['rows'] is an array with row labels as keys and row tags as values.
         * mParams['columns'] is an array with column labels as keys and column tags as values.
         * @param array $value of the options that should be checked
         * @return String
         */
        function getInputHTML( $value ) {
                $html = '';
                $tableContents = '';
                $attribs = array();
                $rows = $this->mParams['rows'];
                $columns = $this->mParams['columns'];

                // If the disabled param is set, disable all the options
                if ( !empty( $this->mParams['disabled'] ) ) {
                        $attribs['disabled'] = 'disabled';
                }

                // Build the column headers
                $headerContents = Html::rawElement( 'td', array(), '&#160;' );
                foreach ( $columns as $columnLabel => $columnTag ) {
                        $headerContents .= Html::rawElement( 'td', array(), $columnLabel );
                }
                $tableContents .= Html::rawElement( 'tr', array(), "\n$headerContents\n" );

                $tooltipClass = 'mw-icon-question';
                if ( isset( $this->mParams['tooltip-class'] ) ) {
                        $tooltipClass = $this->mParams['tooltip-class'];
                }

                // Build the options matrix
                foreach ( $rows as $rowLabel => $rowTag ) {
                        // Append tooltip if configured
                        if ( isset( $this->mParams['tooltips'][$rowLabel] ) ) {
                                $tooltipAttribs = array(
                                        'class' => "mw-htmlform-tooltip $tooltipClass",
                                        'title' =>  $this->mParams['tooltips'][$rowLabel],
                                );
                                $rowLabel .= ' ' . Html::element( 'span', $tooltipAttribs, '' );
                        }
                        $rowContents = Html::rawElement( 'td', array(), $rowLabel );
                        foreach ( $columns as $columnTag ) {
                                $thisTag = "$columnTag-$rowTag";
                                // Construct the checkbox
                                $thisAttribs = array(
                                        'id' => "{$this->mID}-$thisTag",
                                        'value' => $thisTag,
                                );
                                $checked = in_array( $thisTag, (array)$value, true );
                                if ( $this->isTagForcedOff( $thisTag ) ) {
                                        $checked = false;
                                        $thisAttribs['disabled'] = 1;
                                } elseif ( $this->isTagForcedOn( $thisTag ) ) {
                                        $checked = true;
                                        $thisAttribs['disabled'] = 1;
                                }
                                $rowContents .= Html::rawElement(
                                        'td',
                                        array(),
                                        Xml::check( "{$this->mName}[]", $checked, $attribs + $thisAttribs )
                                );
                        }
                        $tableContents .= Html::rawElement( 'tr', array(), "\n$rowContents\n" );
                }

                // Put it all in a table
                $html .= Html::rawElement( 'table', array( 'class' => 'mw-htmlform-matrix' ),
                        Html::rawElement( 'tbody', array(), "\n$tableContents\n" ) ) . "\n";

                return $html;
        }

        protected function isTagForcedOff( $tag ) {
                return isset( $this->mParams['force-options-off'] )
                        && in_array( $tag, $this->mParams['force-options-off'] );
        }

        protected function isTagForcedOn( $tag ) {
                return isset( $this->mParams['force-options-on'] )
                        && in_array( $tag, $this->mParams['force-options-on'] );
        }

        /**
         * Get the complete table row for the input, including help text,
         * labels, and whatever.
         * We override this function since the label should always be on a separate
         * line above the options in the case of a checkbox matrix, i.e. it's always
         * a "vertical-label".
         * @param string $value the value to set the input to
         * @return String complete HTML table row
         */
        function getTableRow( $value ) {
                list( $errors, $errorClass ) = $this->getErrorsAndErrorClass( $value );
                $inputHtml = $this->getInputHTML( $value );
                $fieldType = get_class( $this );
                $helptext = $this->getHelpTextHtmlTable( $this->getHelpText() );
                $cellAttributes = array( 'colspan' => 2 );

                $label = $this->getLabelHtml( $cellAttributes );

                $field = Html::rawElement(
                        'td',
                        array( 'class' => 'mw-input' ) + $cellAttributes,
                        $inputHtml . "\n$errors"
                );

                $html = Html::rawElement( 'tr',
                        array( 'class' => 'mw-htmlform-vertical-label' ), $label );
                $html .= Html::rawElement( 'tr',
                        array( 'class' => "mw-htmlform-field-$fieldType {$this->mClass} $errorClass" ),
                        $field );

                return $html . $helptext;
        }

        /**
         * @param $request WebRequest
         * @return Array
         */
        function loadDataFromRequest( $request ) {
                if ( $this->mParent->getMethod() == 'post' ) {
                        if ( $request->wasPosted() ) {
                                // Checkboxes are not added to the request arrays if they're not checked,
                                // so it's perfectly possible for there not to be an entry at all
                                return $request->getArray( $this->mName, array() );
                        } else {
                                // That's ok, the user has not yet submitted the form, so show the defaults
                                return $this->getDefault();
                        }
                } else {
                        // This is the impossible case: if we look at $_GET and see no data for our
                        // field, is it because the user has not yet submitted the form, or that they
                        // have submitted it with all the options unchecked. We will have to assume the
                        // latter, which basically means that you can't specify 'positive' defaults
                        // for GET forms.
                        return $request->getArray( $this->mName, array() );
                }
        }

        function getDefault() {
                if ( isset( $this->mDefault ) ) {
                        return $this->mDefault;
                } else {
                        return array();
                }
        }

        function filterDataForSubmit( $data ) {
                $columns = HTMLFormField::flattenOptions( $this->mParams['columns'] );
                $rows = HTMLFormField::flattenOptions( $this->mParams['rows'] );
                $res = array();
                foreach ( $columns as $column ) {
                        foreach ( $rows as $row ) {
                                // Make sure option hasn't been forced
                                $thisTag = "$column-$row";
                                if ( $this->isTagForcedOff( $thisTag ) ) {
                                        $res[$thisTag] = false;
                                } elseif ( $this->isTagForcedOn( $thisTag ) ) {
                                        $res[$thisTag] = true;
                                } else {
                                        $res[$thisTag] = in_array( $thisTag, $data );
                                }
                        }
                }

                return $res;
        }
}

/**
 * A select dropdown field.  Basically a wrapper for Xmlselect class
 */
class HTMLSelectField extends HTMLFormField {
        function validate( $value, $alldata ) {
                $p = parent::validate( $value, $alldata );

                if ( $p !== true ) {
                        return $p;
                }

                $validOptions = HTMLFormField::flattenOptions( $this->mParams['options'] );

                if ( in_array( $value, $validOptions ) ) {
                        return true;
                } else {
                        return $this->msg( 'htmlform-select-badoption' )->parse();
                }
        }

        function getInputHTML( $value ) {
                $select = new XmlSelect( $this->mName, $this->mID, strval( $value ) );

                # If one of the options' 'name' is int(0), it is automatically selected.
                # because PHP sucks and thinks int(0) == 'some string'.
                # Working around this by forcing all of them to strings.
                foreach ( $this->mParams['options'] as &$opt ) {
                        if ( is_int( $opt ) ) {
                                $opt = strval( $opt );
                        }
                }
                unset( $opt ); # PHP keeps $opt around as a reference, which is a bit scary

                if ( !empty( $this->mParams['disabled'] ) ) {
                        $select->setAttribute( 'disabled', 'disabled' );
                }

                if ( $this->mClass !== '' ) {
                        $select->setAttribute( 'class', $this->mClass );
                }

                $select->addOptions( $this->mParams['options'] );

                return $select->getHTML();
        }
}

/**
 * Select dropdown field, with an additional "other" textbox.
 */
class HTMLSelectOrOtherField extends HTMLTextField {

        function __construct( $params ) {
                if ( !in_array( 'other', $params['options'], true ) ) {
                        $msg = isset( $params['other'] ) ?
                                $params['other'] :
                                wfMessage( 'htmlform-selectorother-other' )->text();
                        $params['options'][$msg] = 'other';
                }

                parent::__construct( $params );
        }

        static function forceToStringRecursive( $array ) {
                if ( is_array( $array ) ) {
                        return array_map( array( __CLASS__, 'forceToStringRecursive' ), $array );
                } else {
                        return strval( $array );
                }
        }

        function getInputHTML( $value ) {
                $valInSelect = false;

                if ( $value !== false ) {
                        $valInSelect = in_array(
                                $value,
                                HTMLFormField::flattenOptions( $this->mParams['options'] )
                        );
                }

                $selected = $valInSelect ? $value : 'other';

                $opts = self::forceToStringRecursive( $this->mParams['options'] );

                $select = new XmlSelect( $this->mName, $this->mID, $selected );
                $select->addOptions( $opts );

                $select->setAttribute( 'class', 'mw-htmlform-select-or-other' );

                $tbAttribs = array( 'id' => $this->mID . '-other', 'size' => $this->getSize() );

                if ( !empty( $this->mParams['disabled'] ) ) {
                        $select->setAttribute( 'disabled', 'disabled' );
                        $tbAttribs['disabled'] = 'disabled';
                }

                $select = $select->getHTML();

                if ( isset( $this->mParams['maxlength'] ) ) {
                        $tbAttribs['maxlength'] = $this->mParams['maxlength'];
                }

                if ( $this->mClass !== '' ) {
                        $tbAttribs['class'] = $this->mClass;
                }

                $textbox = Html::input(
                        $this->mName . '-other',
                        $valInSelect ? '' : $value,
                        'text',
                        $tbAttribs
                );

                return "$select<br />\n$textbox";
        }

        /**
         * @param  $request WebRequest
         * @return String
         */
        function loadDataFromRequest( $request ) {
                if ( $request->getCheck( $this->mName ) ) {
                        $val = $request->getText( $this->mName );

                        if ( $val == 'other' ) {
                                $val = $request->getText( $this->mName . '-other' );
                        }

                        return $val;
                } else {
                        return $this->getDefault();
                }
        }
}

/**
 * Multi-select field
 */
class HTMLMultiSelectField extends HTMLFormField implements HTMLNestedFilterable {

        function validate( $value, $alldata ) {
                $p = parent::validate( $value, $alldata );

                if ( $p !== true ) {
                        return $p;
                }

                if ( !is_array( $value ) ) {
                        return false;
                }

                # If all options are valid, array_intersect of the valid options
                # and the provided options will return the provided options.
                $validOptions = HTMLFormField::flattenOptions( $this->mParams['options'] );

                $validValues = array_intersect( $value, $validOptions );
                if ( count( $validValues ) == count( $value ) ) {
                        return true;
                } else {
                        return $this->msg( 'htmlform-select-badoption' )->parse();
                }
        }

        function getInputHTML( $value ) {
                $html = $this->formatOptions( $this->mParams['options'], $value );

                return $html;
        }

        function formatOptions( $options, $value ) {
                $html = '';

                $attribs = array();

                if ( !empty( $this->mParams['disabled'] ) ) {
                        $attribs['disabled'] = 'disabled';
                }

                foreach ( $options as $label => $info ) {
                        if ( is_array( $info ) ) {
                                $html .= Html::rawElement( 'h1', array(), $label ) . "\n";
                                $html .= $this->formatOptions( $info, $value );
                        } else {
                                $thisAttribs = array( 'id' => "{$this->mID}-$info", 'value' => $info );

                                $checkbox = Xml::check(
                                        $this->mName . '[]',
                                        in_array( $info, $value, true ),
                                        $attribs + $thisAttribs );
                                $checkbox .= '&#160;' . Html::rawElement( 'label', array( 'for' => "{$this->mID}-$info" ), $label );

                                $html .= ' ' . Html::rawElement( 'div', array( 'class' => 'mw-htmlform-flatlist-item' ), $checkbox );
                        }
                }

                return $html;
        }

        /**
         * @param  $request WebRequest
         * @return String
         */
        function loadDataFromRequest( $request ) {
                if ( $this->mParent->getMethod() == 'post' ) {
                        if ( $request->wasPosted() ) {
                                # Checkboxes are just not added to the request arrays if they're not checked,
                                # so it's perfectly possible for there not to be an entry at all
                                return $request->getArray( $this->mName, array() );
                        } else {
                                # That's ok, the user has not yet submitted the form, so show the defaults
                                return $this->getDefault();
                        }
                } else {
                        # This is the impossible case: if we look at $_GET and see no data for our
                        # field, is it because the user has not yet submitted the form, or that they
                        # have submitted it with all the options unchecked? We will have to assume the
                        # latter, which basically means that you can't specify 'positive' defaults
                        # for GET forms.
                        # @todo FIXME...
                        return $request->getArray( $this->mName, array() );
                }
        }

        function getDefault() {
                if ( isset( $this->mDefault ) ) {
                        return $this->mDefault;
                } else {
                        return array();
                }
        }

        function filterDataForSubmit( $data ) {
                $options = HTMLFormField::flattenOptions( $this->mParams['options'] );

                $res = array();
                foreach ( $options as $opt ) {
                        $res["$opt"] = in_array( $opt, $data );
                }

                return $res;
        }

        protected function needsLabel() {
                return false;
        }
}

/**
 * Double field with a dropdown list constructed from a system message in the format
 *     * Optgroup header
 *     ** <option value>
 *     * New Optgroup header
 * Plus a text field underneath for an additional reason.  The 'value' of the field is
 * "<select>: <extra reason>", or "<extra reason>" if nothing has been selected in the
 * select dropdown.
 * @todo FIXME: If made 'required', only the text field should be compulsory.
 */
class HTMLSelectAndOtherField extends HTMLSelectField {

        function __construct( $params ) {
                if ( array_key_exists( 'other', $params ) ) {
                } elseif ( array_key_exists( 'other-message', $params ) ) {
                        $params['other'] = wfMessage( $params['other-message'] )->plain();
                } else {
                        $params['other'] = null;
                }

                if ( array_key_exists( 'options', $params ) ) {
                        # Options array already specified
                } elseif ( array_key_exists( 'options-message', $params ) ) {
                        # Generate options array from a system message
                        $params['options'] = self::parseMessage(
                                wfMessage( $params['options-message'] )->inContentLanguage()->plain(),
                                $params['other']
                        );
                } else {
                        # Sulk
                        throw new MWException( 'HTMLSelectAndOtherField called without any options' );
                }
                $this->mFlatOptions = self::flattenOptions( $params['options'] );

                parent::__construct( $params );
        }

        /**
         * Build a drop-down box from a textual list.
         * @param string $string message text
         * @param string $otherName name of "other reason" option
         * @return Array
         * TODO: this is copied from Xml::listDropDown(), deprecate/avoid duplication?
         */
        public static function parseMessage( $string, $otherName = null ) {
                if ( $otherName === null ) {
                        $otherName = wfMessage( 'htmlform-selectorother-other' )->plain();
                }

                $optgroup = false;
                $options = array( $otherName => 'other' );

                foreach ( explode( "\n", $string ) as $option ) {
                        $value = trim( $option );
                        if ( $value == '' ) {
                                continue;
                        } elseif ( substr( $value, 0, 1 ) == '*' && substr( $value, 1, 1 ) != '*' ) {
                                # A new group is starting...
                                $value = trim( substr( $value, 1 ) );
                                $optgroup = $value;
                        } elseif ( substr( $value, 0, 2 ) == '**' ) {
                                # groupmember
                                $opt = trim( substr( $value, 2 ) );
                                if ( $optgroup === false ) {
                                        $options[$opt] = $opt;
                                } else {
                                        $options[$optgroup][$opt] = $opt;
                                }
                        } else {
                                # groupless reason list
                                $optgroup = false;
                                $options[$option] = $option;
                        }
                }

                return $options;
        }

        function getInputHTML( $value ) {
                $select = parent::getInputHTML( $value[1] );

                $textAttribs = array(
                        'id' => $this->mID . '-other',
                        'size' => $this->getSize(),
                );

                if ( $this->mClass !== '' ) {
                        $textAttribs['class'] = $this->mClass;
                }

                foreach ( array( 'required', 'autofocus', 'multiple', 'disabled' ) as $param ) {
                        if ( isset( $this->mParams[$param] ) ) {
                                $textAttribs[$param] = '';
                        }
                }

                $textbox = Html::input(
                        $this->mName . '-other',
                        $value[2],
                        'text',
                        $textAttribs
                );

                return "$select<br />\n$textbox";
        }

        /**
         * @param  $request WebRequest
         * @return Array("<overall message>","<select value>","<text field value>")
         */
        function loadDataFromRequest( $request ) {
                if ( $request->getCheck( $this->mName ) ) {

                        $list = $request->getText( $this->mName );
                        $text = $request->getText( $this->mName . '-other' );

                        if ( $list == 'other' ) {
                                $final = $text;
                        } elseif ( !in_array( $list, $this->mFlatOptions ) ) {
                                # User has spoofed the select form to give an option which wasn't
                                # in the original offer.  Sulk...
                                $final = $text;
                        } elseif ( $text == '' ) {
                                $final = $list;
                        } else {
                                $final = $list . $this->msg( 'colon-separator' )->inContentLanguage()->text() . $text;
                        }

                } else {
                        $final = $this->getDefault();

                        $list = 'other';
                        $text = $final;
                        foreach ( $this->mFlatOptions as $option ) {
                                $match = $option . $this->msg( 'colon-separator' )->inContentLanguage()->text();
                                if ( strpos( $text, $match ) === 0 ) {
                                        $list = $option;
                                        $text = substr( $text, strlen( $match ) );
                                        break;
                                }
                        }
                }
                return array( $final, $list, $text );
        }

        function getSize() {
                return isset( $this->mParams['size'] )
                        ? $this->mParams['size']
                        : 45;
        }

        function validate( $value, $alldata ) {
                # HTMLSelectField forces $value to be one of the options in the select
                # field, which is not useful here.  But we do want the validation further up
                # the chain
                $p = parent::validate( $value[1], $alldata );

                if ( $p !== true ) {
                        return $p;
                }

                if ( isset( $this->mParams['required'] ) && $this->mParams['required'] !== false && $value[1] === '' ) {
                        return $this->msg( 'htmlform-required' )->parse();
                }

                return true;
        }
}

/**
 * Radio checkbox fields.
 */
class HTMLRadioField extends HTMLFormField {

        function validate( $value, $alldata ) {
                $p = parent::validate( $value, $alldata );

                if ( $p !== true ) {
                        return $p;
                }

                if ( !is_string( $value ) && !is_int( $value ) ) {
                        return false;
                }

                $validOptions = HTMLFormField::flattenOptions( $this->mParams['options'] );

                if ( in_array( $value, $validOptions ) ) {
                        return true;
                } else {
                        return $this->msg( 'htmlform-select-badoption' )->parse();
                }
        }

        /**
         * This returns a block of all the radio options, in one cell.
         * @see includes/HTMLFormField#getInputHTML()
         * @param $value String
         * @return String
         */
        function getInputHTML( $value ) {
                $html = $this->formatOptions( $this->mParams['options'], $value );

                return $html;
        }

        function formatOptions( $options, $value ) {
                $html = '';

                $attribs = array();
                if ( !empty( $this->mParams['disabled'] ) ) {
                        $attribs['disabled'] = 'disabled';
                }

                # TODO: should this produce an unordered list perhaps?
                foreach ( $options as $label => $info ) {
                        if ( is_array( $info ) ) {
                                $html .= Html::rawElement( 'h1', array(), $label ) . "\n";
                                $html .= $this->formatOptions( $info, $value );
                        } else {
                                $id = Sanitizer::escapeId( $this->mID . "-$info" );
                                $radio = Xml::radio(
                                        $this->mName,
                                        $info,
                                        $info == $value,
                                        $attribs + array( 'id' => $id )
                                );
                                $radio .= '&#160;' .
                                                Html::rawElement( 'label', array( 'for' => $id ), $label );

                                $html .= ' ' . Html::rawElement( 'div', array( 'class' => 'mw-htmlform-flatlist-item' ), $radio );
                        }
                }

                return $html;
        }

        protected function needsLabel() {
                return false;
        }
}

/**
 * An information field (text blob), not a proper input.
 */
class HTMLInfoField extends HTMLFormField {
        public function __construct( $info ) {
                $info['nodata'] = true;

                parent::__construct( $info );
        }

        public function getInputHTML( $value ) {
                return !empty( $this->mParams['raw'] ) ? $value : htmlspecialchars( $value );
        }

        public function getTableRow( $value ) {
                if ( !empty( $this->mParams['rawrow'] ) ) {
                        return $value;
                }

                return parent::getTableRow( $value );
        }

        /**
         * @since 1.20
         */
        public function getDiv( $value ) {
                if ( !empty( $this->mParams['rawrow'] ) ) {
                        return $value;
                }

                return parent::getDiv( $value );
        }

        /**
         * @since 1.20
         */
        public function getRaw( $value ) {
                if ( !empty( $this->mParams['rawrow'] ) ) {
                        return $value;
                }

                return parent::getRaw( $value );
        }

        protected function needsLabel() {
                return false;
        }
}

class HTMLHiddenField extends HTMLFormField {
        public function __construct( $params ) {
                parent::__construct( $params );

                # Per HTML5 spec, hidden fields cannot be 'required'
                # http://dev.w3.org/html5/spec/states-of-the-type-attribute.html#hidden-state
                unset( $this->mParams['required'] );
        }

        public function getTableRow( $value ) {
                $params = array();
                if ( $this->mID ) {
                        $params['id'] = $this->mID;
                }

                $this->mParent->addHiddenField(
                        $this->mName,
                        $this->mDefault,
                        $params
                );

                return '';
        }

        /**
         * @since 1.20
         */
        public function getDiv( $value ) {
                return $this->getTableRow( $value );
        }

        /**
         * @since 1.20
         */
        public function getRaw( $value ) {
                return $this->getTableRow( $value );
        }

        public function getInputHTML( $value ) {
                return '';
        }
}

/**
 * Add a submit button inline in the form (as opposed to
 * HTMLForm::addButton(), which will add it at the end).
 */
class HTMLSubmitField extends HTMLButtonField {
        protected $buttonType = 'submit';
}

/**
 * Adds a generic button inline to the form. Does not do anything, you must add
 * click handling code in JavaScript. Use a HTMLSubmitField if you merely
 * wish to add a submit button to a form.
 *
 * @since 1.22
 */
class HTMLButtonField extends HTMLFormField {
        protected $buttonType = 'button';

        public function __construct( $info ) {
                $info['nodata'] = true;
                parent::__construct( $info );
        }

        public function getInputHTML( $value ) {
                $attr = array(
                        'class' => 'mw-htmlform-submit ' . $this->mClass,
                        'id' => $this->mID,
                );

                if ( !empty( $this->mParams['disabled'] ) ) {
                        $attr['disabled'] = 'disabled';
                }

                return Html::input(
                        $this->mName,
                        $value,
                        $this->buttonType,
                        $attr
                );
        }

        protected function needsLabel() {
                return false;
        }

        /**
         * Button cannot be invalid
         * @param $value String
         * @param $alldata Array
         * @return Bool
         */
        public function validate( $value, $alldata ) {
                return true;
        }
}

class HTMLEditTools extends HTMLFormField {
        public function getInputHTML( $value ) {
                return '';
        }

        public function getTableRow( $value ) {
                $msg = $this->formatMsg();

                return '<tr><td></td><td class="mw-input">'
                        . '<div class="mw-editTools">'
                        . $msg->parseAsBlock()
                        . "</div></td></tr>\n";
        }

        /**
         * @since 1.20
         */
        public function getDiv( $value ) {
                $msg = $this->formatMsg();
                return '<div class="mw-editTools">' . $msg->parseAsBlock() . '</div>';
        }

        /**
         * @since 1.20
         */
        public function getRaw( $value ) {
                return $this->getDiv( $value );
        }

        protected function formatMsg() {
                if ( empty( $this->mParams['message'] ) ) {
                        $msg = $this->msg( 'edittools' );
                } else {
                        $msg = $this->msg( $this->mParams['message'] );
                        if ( $msg->isDisabled() ) {
                                $msg = $this->msg( 'edittools' );
                        }
                }
                $msg->inContentLanguage();
                return $msg;
        }
}

class HTMLApiField extends HTMLFormField {
        public function getTableRow( $value ) {
                return '';
        }

        public function getDiv( $value ) {
                return $this->getTableRow( $value );
        }

        public function getRaw( $value ) {
                return $this->getTableRow( $value );
        }

        public function getInputHTML( $value ) {
                return '';
        }
}

interface HTMLNestedFilterable {
        /**
         * Support for seperating multi-option preferences into multiple preferences
         * Due to lack of array support.
         * @param $data array
         */
        function filterDataForSubmit( $data );
}

class HTMLFormFieldRequiredOptionsException extends MWException {
        public function __construct( HTMLFormField $field, array $missing ) {
                parent::__construct( sprintf(
                        "Form type `%s` expected the following parameters to be set: %s",
                        get_class( $field ),
                        implode( ', ', $missing )
                ) );
        }
}