Remove unneeded commented code, that I accidently added in r82461

[mediawiki.git] / includes / Message.php

<?php
/**
 * This class provides methods for fetching interface messages and
 * processing them into variety of formats that are needed in MediaWiki.
 *
 * It is intented to replace the old wfMsg* functions that over time grew
 * unusable.
 *
 * Examples:
 * Fetching a message text for interface message
 *    $button = Xml::button( wfMessage( 'submit' )->text() );
 * </pre>
 * Messages can have parameters:
 *    wfMessage( 'welcome-to' )->params( $wgSitename )->text(); 
 *        {{GRAMMAR}} and friends work correctly
 *    wfMessage( 'are-friends', $user, $friend );
 *    wfMessage( 'bad-message' )->rawParams( '<script>...</script>' )->escaped();
 * </pre>
 * Sometimes the message text ends up in the database, so content language is needed.
 *    wfMessage( 'file-log', $user, $filename )->inContentLanguage()->text()
 * </pre>
 * Checking if message exists:
 *    wfMessage( 'mysterious-message' )->exists()
 * </pre>
 * If you want to use a different language:
 *    wfMessage( 'email-header' )->inLanguage( $user->getOption( 'language' ) )->plain()
 *        Note that you cannot parse the text except in the content or interface
 *        languages
 * </pre>
 *
 *
 * Comparison with old wfMsg* functions:
 *
 * Use full parsing.
 *     wfMsgExt( 'key', array( 'parseinline' ), 'apple' );
 *     === wfMessage( 'key', 'apple' )->parse();
 * </pre>
 * Parseinline is used because it is more useful when pre-building html.
 * In normal use it is better to use OutputPage::(add|wrap)WikiMsg.
 *
 * Places where html cannot be used. {{-transformation is done.
 *     wfMsgExt( 'key', array( 'parsemag' ), 'apple', 'pear' );
 *     === wfMessage( 'key', 'apple', 'pear' )->text();
 * </pre>
 *
 * Shortcut for escaping the message too, similar to wfMsgHTML, but
 * parameters are not replaced after escaping by default.
 * $escaped = wfMessage( 'key' )->rawParams( 'apple' )->escaped();
 * </pre>
 *
 * TODO:
 * - test, can we have tests?
 * - sort out the details marked with fixme
 *
 * @since 1.17
 * @author Niklas Laxström
 */
class Message {
        /**
         * In which language to get this message. True, which is the default,
         * means the current interface language, false content language.
         */
        protected $interface = true;
        
        /**
         * In which language to get this message. Overrides the $interface
         * variable.
         */
        protected $language = null;
        
        /**
         * The message key.
         */
        protected $key;

        /**
         * List of parameters which will be substituted into the message.
         */
        protected $parameters = array();

        /**
         * Format for the message.
         * Supported formats are:
         * * text (transform)
         * * escaped (transform+htmlspecialchars)
         * * block-parse
         * * parse (default)
         * * plain
         */
        protected $format = 'parse';

        /**
         * Whether database can be used.
         */
        protected $useDatabase = true;

        /**
         * Title object to use as context
         */
        protected $title = null;

        /**
         * Constructor.
         * @param $key: message key, or array of message keys to try and use the first non-empty message for
         * @param $params Array message parameters
         * @return Message: $this
         */
        public function __construct( $key, $params = array() ) {
                global $wgLang;
                $this->key = $key;
                $this->parameters = array_values( $params );
                $this->language = $wgLang;
        }

        /**
         * Factory function that is just wrapper for the real constructor. It is
         * intented to be used instead of the real constructor, because it allows
         * chaining method calls, while new objects don't.
         * @param $key String: message key
         * @param Varargs: parameters as Strings
         * @return Message: $this
         */
        public static function newFromKey( $key /*...*/ ) {
                $params = func_get_args();
                array_shift( $params );
                return new self( $key, $params );
        }

        /**
         * Factory function accepting multiple message keys and returning a message instance
         * for the first message which is non-empty. If all messages are empty then an
         * instance of the first message key is returned.
         * @param Varargs: message keys
         * @return Message: $this
         */
        public static function newFallbackSequence( /*...*/ ) {
                $keys = func_get_args();
                if ( func_num_args() == 1 ) {
                        if ( is_array($keys[0]) ) {
                                // Allow an array to be passed as the first argument instead
                                $keys = array_values($keys[0]);
                        } else {
                                // Optimize a single string to not need special fallback handling
                                $keys = $keys[0];
                        }
                }
                return new self( $keys );
        }

        /**
         * Adds parameters to the parameter list of this message.
         * @param Varargs: parameters as Strings
         * @return Message: $this
         */
        public function params( /*...*/ ) {
                $args = func_get_args();
                if ( isset( $args[0] ) && is_array( $args[0] ) ) {
                        $args = $args[0];
                }
                $args_values = array_values( $args );
                $this->parameters = array_merge( $this->parameters, $args_values );
                return $this;
        }

        /**
         * Add parameters that are substituted after parsing or escaping.
         * In other words the parsing process cannot access the contents
         * of this type of parameter, and you need to make sure it is
         * sanitized beforehand.  The parser will see "$n", instead.
         * @param Varargs: raw parameters as Strings
         * @return Message: $this
         */
        public function rawParams( /*...*/ ) {
                $params = func_get_args();
                if ( isset( $params[0] ) && is_array( $params[0] ) ) {
                        $params = $params[0];
                }
                foreach( $params as $param ) {
                        $this->parameters[] = self::rawParam( $param );
                }
                return $this;
        }
        
        /**
         * Add parameters that are numeric and will be passed through
         * Language::formatNum before substitution
         * @param Varargs: numeric parameters
         * @return Message: $this
         */
        public function numParams( /*...*/ ) {
                $params = func_get_args();
                if ( isset( $params[0] ) && is_array( $params[0] ) ) {
                        $params = $params[0];
                }
                foreach( $params as $param ) {
                        $this->parameters[] = self::numParam( $param );
                }
                return $this;
        }
        
        /**
         * Request the message in any language that is supported.
         * As a side effect interface message status is unconditionally
         * turned off.
         * @param $lang Mixed: language code or Language object.
         * @return Message: $this
         */
        public function inLanguage( $lang ) {
                if( $lang instanceof Language ){
                        $this->language = $lang;
                } elseif ( is_string( $lang ) ) {
                        if( $this->language->getCode() != $lang ) {
                                $this->language = Language::factory( $lang );
                        }
                } else {
                        $type = gettype( $lang );
                        throw new MWException( __METHOD__ . " must be "
                                . "passed a String or Language object; $type given" 
                        );
                }
                $this->interface = false;
                return $this;
        }

        /**
         * Request the message in the wiki's content language.
         * @return Message: $this
         */
        public function inContentLanguage() {
                global $wgContLang;
                $this->interface = false;
                $this->language = $wgContLang;
                return $this;
        }

        /**
         * Enable or disable database use.
         * @param $value Boolean
         * @return Message: $this
         */
        public function useDatabase( $value ) {
                $this->useDatabase = (bool) $value;
                return $this;
        }

        /**
         * Set the Title object to use as context when transforming the message
         *
         * @param $title Title object
         * @return Message: $this
         */
        public function title( $title ) {
                $this->title = $title;
                return $this;
        }

        /**
         * Returns the message parsed from wikitext to HTML.
         * TODO: in PHP >= 5.2.0, we can make this a magic method,
         * and then we can do, eg:
         *     $foo = Message::get($key);
         *     $string = "<abbr>$foo</abbr>";
         * But we shouldn't implement that while MediaWiki still supports
         * PHP < 5.2; or people will start using it...
         * @return String: HTML
         */
        public function toString() {
                $string = $this->getMessageText();
                
                # Replace parameters before text parsing
                $string = $this->replaceParameters( $string, 'before' );
                
                # Maybe transform using the full parser
                if( $this->format === 'parse' ) {
                        $string = $this->parseText( $string );
                        $m = array();
                        if( preg_match( '/^<p>(.*)\n?<\/p>\n?$/sU', $string, $m ) ) {
                                $string = $m[1];
                        }
                } elseif( $this->format === 'block-parse' ){
                        $string = $this->parseText( $string );
                } elseif( $this->format === 'text' ){
                        $string = $this->transformText( $string );
                } elseif( $this->format === 'escaped' ){
                        # FIXME: Sanitizer method here?
                        $string = $this->transformText( $string );
                        $string = htmlspecialchars( $string );
                }
                
                # Raw parameter replacement
                $string = $this->replaceParameters( $string, 'after' );
                
                return $string;
        }
        
        /**
         * Fully parse the text from wikitext to HTML
         * @return String parsed HTML
         */
        public function parse() {
                $this->format = 'parse';
                return $this->toString();
        }

        /**
         * Returns the message text. {{-transformation is done.
         * @return String: Unescaped message text.
         */
        public function text() {
                $this->format = 'text';
                return $this->toString();
        }

        /**
         * Returns the message text as-is, only parameters are subsituted.
         * @return String: Unescaped untransformed message text.
         */
        public function plain() {
                $this->format = 'plain';
                return $this->toString();
        }

        /**
         * Returns the parsed message text which is always surrounded by a block element.
         * @return String: HTML
         */
        public function parseAsBlock() {
                $this->format = 'block-parse';
                return $this->toString();
        }

        /**
         * Returns the message text. {{-transformation is done and the result
         * is escaped excluding any raw parameters.
         * @return String: Escaped message text.
         */
        public function escaped() {
                $this->format = 'escaped';
                return $this->toString();
        }

        /**
         * Check whether a message key has been defined currently.
         * @return Bool: true if it is and false if not.
         */
        public function exists() {
                return $this->fetchMessage() !== false;
        }

        /**
         * Check whether a message does not exist, or is an empty string
         * @return Bool: true if is is and false if not
         * @todo Merge with isDisabled()?
         */
        public function isBlank() {
                $message = $this->fetchMessage();
                return $message === false || $message === '';
        }

        /**
         * Check whether a message does not exist, is an empty string, or is "-"
         * @return Bool: true if is is and false if not
         */
        public function isDisabled() {
                $message = $this->fetchMessage();
                return $message === false || $message === '' || $message === '-';
        }

        public static function rawParam( $value ) {
                return array( 'raw' => $value );
        }
        
        public static function numParam( $value ) {
                return array( 'num' => $value );
        }

        /**
         * Substitutes any paramaters into the message text.
         * @param $message String: the message text
         * @param $type String: either before or after
         * @return String
         */
        protected function replaceParameters( $message, $type = 'before' ) {
                $replacementKeys = array();
                foreach( $this->parameters as $n => $param ) {
                        list( $paramType, $value ) = $this->extractParam( $param );
                        if ( $type === $paramType ) {
                                $replacementKeys['$' . ($n + 1)] = $value;
                        }
                }
                $message = strtr( $message, $replacementKeys );
                return $message;
        }

        /**
         * Extracts the parameter type and preprocessed the value if needed.
         * @param $param String|Array: Parameter as defined in this class.
         * @return Tuple(type, value)
         * @throws MWException
         */
        protected function extractParam( $param ) {
                if ( is_array( $param ) && isset( $param['raw'] ) ) {
                        return array( 'after', $param['raw'] );
                } elseif ( is_array( $param ) && isset( $param['num'] ) ) {
                        // Replace number params always in before step for now.
                        // No support for combined raw and num params
                        return array( 'before', $this->language->formatNum( $param['num'] ) );
                } elseif ( !is_array( $param ) ) {
                        return array( 'before', $param );
                } else {
                        throw new MWException( "Invalid message parameter" );
                }
        }

        /**
         * Wrapper for what ever method we use to parse wikitext.
         * @param $string String: Wikitext message contents
         * @return Wikitext parsed into HTML
         */
        protected function parseText( $string ) {
                global $wgOut;
                return $wgOut->parse( $string, /*linestart*/true, $this->interface, $this->language );
        }

        /**
         * Wrapper for what ever method we use to {{-transform wikitext.
         * @param $string String: Wikitext message contents
         * @return Wikitext with {{-constructs replaced with their values.
         */
        protected function transformText( $string ) {
                return MessageCache::singleton()->transform( $string, $this->interface, $this->language, $this->title );
        }

        /**
         * Returns the textual value for the message.
         * @return Message contents or placeholder
         */
        protected function getMessageText() {
                $message = $this->fetchMessage();
                if ( $message === false ) {
                        return '&lt;' . htmlspecialchars( is_array($this->key) ? $this->key[0] : $this->key ) . '&gt;';
                } else {
                        return $message;
                }
        }

        /**
         * Wrapper for what ever method we use to get message contents
         */
        protected function fetchMessage() {
                if ( !isset( $this->message ) ) {
                        $cache = MessageCache::singleton();
                        if ( is_array($this->key) ) {
                                foreach ( $this->key as $key ) {
                                        $message = $cache->get( $key, $this->useDatabase, $this->language );
                                        if ( $message !== false && $message !== '' ) {
                                                break;
                                        }
                                }
                                $this->message = $message;
                        } else {
                                $this->message = $cache->get( $this->key, $this->useDatabase, $this->language );
                        }
                }
                return $this->message;
        }

}