Implement extension registration from an extension.json file

[mediawiki.git] / includes / Status.php

<?php
/**
 * Generic operation result.
 *
 * 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
 */

/**
 * Generic operation result class
 * Has warning/error list, boolean status and arbitrary value
 *
 * "Good" means the operation was completed with no warnings or errors.
 *
 * "OK" means the operation was partially or wholly completed.
 *
 * An operation which is not OK should have errors so that the user can be
 * informed as to what went wrong. Calling the fatal() function sets an error
 * message and simultaneously switches off the OK flag.
 *
 * The recommended pattern for Status objects is to return a Status object
 * unconditionally, i.e. both on success and on failure -- so that the
 * developer of the calling code is reminded that the function can fail, and
 * so that a lack of error-handling will be explicit.
 */
class Status {
        /** @var bool */
        public $ok = true;

        /** @var mixed */
        public $value;

        /** Counters for batch operations */
        /** @var int */
        public $successCount = 0;

        /** @var int */
        public $failCount = 0;

        /** Array to indicate which items of the batch operations were successful */
        /** @var array */
        public $success = array();

        /** @var array */
        public $errors = array();

        /** @var callable */
        public $cleanCallback = false;

        /**
         * Factory function for fatal errors
         *
         * @param string|Message $message Message name or object
         * @return Status
         */
        static function newFatal( $message /*, parameters...*/ ) {
                $params = func_get_args();
                $result = new self;
                call_user_func_array( array( &$result, 'error' ), $params );
                $result->ok = false;
                return $result;
        }

        /**
         * Factory function for good results
         *
         * @param mixed $value
         * @return Status
         */
        static function newGood( $value = null ) {
                $result = new self;
                $result->value = $value;
                return $result;
        }

        /**
         * Change operation result
         *
         * @param bool $ok Whether the operation completed
         * @param mixed $value
         */
        public function setResult( $ok, $value = null ) {
                $this->ok = $ok;
                $this->value = $value;
        }

        /**
         * Returns whether the operation completed and didn't have any error or
         * warnings
         *
         * @return bool
         */
        public function isGood() {
                return $this->ok && !$this->errors;
        }

        /**
         * Returns whether the operation completed
         *
         * @return bool
         */
        public function isOK() {
                return $this->ok;
        }

        /**
         * Add a new warning
         *
         * @param string|Message $message Message name or object
         */
        public function warning( $message /*, parameters... */ ) {
                $params = array_slice( func_get_args(), 1 );
                $this->errors[] = array(
                        'type' => 'warning',
                        'message' => $message,
                        'params' => $params );
        }

        /**
         * Add an error, do not set fatal flag
         * This can be used for non-fatal errors
         *
         * @param string|Message $message Message name or object
         */
        public function error( $message /*, parameters... */ ) {
                $params = array_slice( func_get_args(), 1 );
                $this->errors[] = array(
                        'type' => 'error',
                        'message' => $message,
                        'params' => $params );
        }

        /**
         * Add an error and set OK to false, indicating that the operation
         * as a whole was fatal
         *
         * @param string|Message $message Message name or object
         */
        public function fatal( $message /*, parameters... */ ) {
                $params = array_slice( func_get_args(), 1 );
                $this->errors[] = array(
                        'type' => 'error',
                        'message' => $message,
                        'params' => $params );
                $this->ok = false;
        }

        /**
         * Don't save the callback when serializing, because Closures can't be
         * serialized and we're going to clear it in __wakeup anyway.
         */
        public function __sleep() {
                $keys = array_keys( get_object_vars( $this ) );
                return array_diff( $keys, array( 'cleanCallback' ) );
        }

        /**
         * Sanitize the callback parameter on wakeup, to avoid arbitrary execution.
         */
        public function __wakeup() {
                $this->cleanCallback = false;
        }

        /**
         * @param array $params
         * @return array
         */
        protected function cleanParams( $params ) {
                if ( !$this->cleanCallback ) {
                        return $params;
                }
                $cleanParams = array();
                foreach ( $params as $i => $param ) {
                        $cleanParams[$i] = call_user_func( $this->cleanCallback, $param );
                }
                return $cleanParams;
        }

        /**
         * Get the error list as a wikitext formatted list
         *
         * @param string|bool $shortContext A short enclosing context message name, to
         *        be used when there is a single error
         * @param string|bool $longContext A long enclosing context message name, for a list
         * @return string
         */
        public function getWikiText( $shortContext = false, $longContext = false ) {
                if ( count( $this->errors ) == 0 ) {
                        if ( $this->ok ) {
                                $this->fatal( 'internalerror_info',
                                        __METHOD__ . " called for a good result, this is incorrect\n" );
                        } else {
                                $this->fatal( 'internalerror_info',
                                        __METHOD__ . ": Invalid result object: no error text but not OK\n" );
                        }
                }
                if ( count( $this->errors ) == 1 ) {
                        $s = $this->getErrorMessage( $this->errors[0] )->plain();
                        if ( $shortContext ) {
                                $s = wfMessage( $shortContext, $s )->plain();
                        } elseif ( $longContext ) {
                                $s = wfMessage( $longContext, "* $s\n" )->plain();
                        }
                } else {
                        $errors = $this->getErrorMessageArray( $this->errors );
                        foreach ( $errors as &$error ) {
                                $error = $error->plain();
                        }
                        $s = '* ' . implode( "\n* ", $errors ) . "\n";
                        if ( $longContext ) {
                                $s = wfMessage( $longContext, $s )->plain();
                        } elseif ( $shortContext ) {
                                $s = wfMessage( $shortContext, "\n$s\n" )->plain();
                        }
                }
                return $s;
        }

        /**
         * Get the error list as a Message object
         *
         * @param string|string[] $shortContext A short enclosing context message name (or an array of
         * message names), to be used when there is a single error.
         * @param string|string[] $longContext A long enclosing context message name (or an array of
         * message names), for a list.
         *
         * @return Message
         */
        public function getMessage( $shortContext = false, $longContext = false ) {
                if ( count( $this->errors ) == 0 ) {
                        if ( $this->ok ) {
                                $this->fatal( 'internalerror_info',
                                        __METHOD__ . " called for a good result, this is incorrect\n" );
                        } else {
                                $this->fatal( 'internalerror_info',
                                        __METHOD__ . ": Invalid result object: no error text but not OK\n" );
                        }
                }
                if ( count( $this->errors ) == 1 ) {
                        $s = $this->getErrorMessage( $this->errors[0] );
                        if ( $shortContext ) {
                                $s = wfMessage( $shortContext, $s );
                        } elseif ( $longContext ) {
                                $wrapper = new RawMessage( "* \$1\n" );
                                $wrapper->params( $s )->parse();
                                $s = wfMessage( $longContext, $wrapper );
                        }
                } else {
                        $msgs = $this->getErrorMessageArray( $this->errors );
                        $msgCount = count( $msgs );

                        if ( $shortContext ) {
                                $msgCount++;
                        }

                        $s = new RawMessage( '* $' . implode( "\n* \$", range( 1, $msgCount ) ) );
                        $s->params( $msgs )->parse();

                        if ( $longContext ) {
                                $s = wfMessage( $longContext, $s );
                        } elseif ( $shortContext ) {
                                $wrapper = new RawMessage( "\n\$1\n", $s );
                                $wrapper->parse();
                                $s = wfMessage( $shortContext, $wrapper );
                        }
                }

                return $s;
        }

        /**
         * Return the message for a single error.
         * @param mixed $error With an array & two values keyed by
         * 'message' and 'params', use those keys-value pairs.
         * Otherwise, if its an array, just use the first value as the
         * message and the remaining items as the params.
         *
         * @return string
         */
        protected function getErrorMessage( $error ) {
                if ( is_array( $error ) ) {
                        if ( isset( $error['message'] ) && $error['message'] instanceof Message ) {
                                $msg = $error['message'];
                        } elseif ( isset( $error['message'] ) && isset( $error['params'] ) ) {
                                $msg = wfMessage( $error['message'],
                                        array_map( 'wfEscapeWikiText', $this->cleanParams( $error['params'] ) ) );
                        } else {
                                $msgName = array_shift( $error );
                                $msg = wfMessage( $msgName,
                                        array_map( 'wfEscapeWikiText', $this->cleanParams( $error ) ) );
                        }
                } else {
                        $msg = wfMessage( $error );
                }
                return $msg;
        }

        /**
         * Get the error message as HTML. This is done by parsing the wikitext error
         * message.
         * @param string $shortContext A short enclosing context message name, to
         *        be used when there is a single error
         * @param string $longContext A long enclosing context message name, for a list
         * @return string
         */
        public function getHTML( $shortContext = false, $longContext = false ) {
                $text = $this->getWikiText( $shortContext, $longContext );
                $out = MessageCache::singleton()->parse( $text, null, true, true );
                return $out instanceof ParserOutput ? $out->getText() : $out;
        }

        /**
         * Return an array with the wikitext for each item in the array.
         * @param array $errors
         * @return array
         */
        protected function getErrorMessageArray( $errors ) {
                return array_map( array( $this, 'getErrorMessage' ), $errors );
        }

        /**
         * Merge another status object into this one
         *
         * @param Status $other Other Status object
         * @param bool $overwriteValue Whether to override the "value" member
         */
        public function merge( $other, $overwriteValue = false ) {
                $this->errors = array_merge( $this->errors, $other->errors );
                $this->ok = $this->ok && $other->ok;
                if ( $overwriteValue ) {
                        $this->value = $other->value;
                }
                $this->successCount += $other->successCount;
                $this->failCount += $other->failCount;
        }

        /**
         * Get the list of errors (but not warnings)
         *
         * @return array A list in which each entry is an array with a message key as its first element.
         *         The remaining array elements are the message parameters.
         */
        public function getErrorsArray() {
                return $this->getStatusArray( "error" );
        }

        /**
         * Get the list of warnings (but not errors)
         *
         * @return array A list in which each entry is an array with a message key as its first element.
         *         The remaining array elements are the message parameters.
         */
        public function getWarningsArray() {
                return $this->getStatusArray( "warning" );
        }

        /**
         * Returns a list of status messages of the given type (or all if false)
         * @param string $type
         * @return array
         */
        protected function getStatusArray( $type = false ) {
                $result = array();
                foreach ( $this->errors as $error ) {
                        if ( $type === false || $error['type'] === $type ) {
                                if ( $error['message'] instanceof Message ) {
                                        $result[] = array_merge(
                                                array( $error['message']->getKey() ),
                                                $error['message']->getParams()
                                        );
                                } elseif ( $error['params'] ) {
                                        $result[] = array_merge( array( $error['message'] ), $error['params'] );
                                } else {
                                        $result[] = array( $error['message'] );
                                }
                        }
                }

                return $result;
        }

        /**
         * Returns a list of status messages of the given type, with message and
         * params left untouched, like a sane version of getStatusArray
         *
         * @param string $type
         *
         * @return array
         */
        public function getErrorsByType( $type ) {
                $result = array();
                foreach ( $this->errors as $error ) {
                        if ( $error['type'] === $type ) {
                                $result[] = $error;
                        }
                }
                return $result;
        }

        /**
         * Returns true if the specified message is present as a warning or error
         *
         * @param string|Message $message Message key or object to search for
         *
         * @return bool
         */
        public function hasMessage( $message ) {
                if ( $message instanceof Message ) {
                        $message = $message->getKey();
                }
                foreach ( $this->errors as $error ) {
                        if ( $error['message'] instanceof Message
                                && $error['message']->getKey() === $message
                        ) {
                                return true;
                        } elseif ( $error['message'] === $message ) {
                                return true;
                        }
                }
                return false;
        }

        /**
         * If the specified source message exists, replace it with the specified
         * destination message, but keep the same parameters as in the original error.
         *
         * Note, due to the lack of tools for comparing Message objects, this
         * function will not work when using a Message object as the search parameter.
         *
         * @param Message|string $source Message key or object to search for
         * @param Message|string $dest Replacement message key or object
         * @return bool Return true if the replacement was done, false otherwise.
         */
        public function replaceMessage( $source, $dest ) {
                $replaced = false;
                foreach ( $this->errors as $index => $error ) {
                        if ( $error['message'] === $source ) {
                                $this->errors[$index]['message'] = $dest;
                                $replaced = true;
                        }
                }
                return $replaced;
        }

        /**
         * @return mixed
         */
        public function getValue() {
                return $this->value;
        }

        /**
         * @return string
         */
        public function __toString() {
                $status = $this->isOK() ? "OK" : "Error";
                if ( count( $this->errors ) ) {
                        $errorcount = "collected " . ( count( $this->errors ) ) . " error(s) on the way";
                } else {
                        $errorcount = "no errors detected";
                }
                if ( isset( $this->value ) ) {
                        $valstr = gettype( $this->value ) . " value set";
                        if ( is_object( $this->value ) ) {
                                $valstr .= "\"" . get_class( $this->value ) . "\" instance";
                        }
                } else {
                        $valstr = "no value set";
                }
                $out = sprintf( "<%s, %s, %s>",
                        $status,
                        $errorcount,
                        $valstr
                );
                if ( count( $this->errors ) > 0 ) {
                        $hdr = sprintf( "+-%'-4s-+-%'-25s-+-%'-40s-+\n", "", "", "" );
                        $i = 1;
                        $out .= "\n";
                        $out .= $hdr;
                        foreach ( $this->getStatusArray() as $stat ) {
                                $out .= sprintf( "| %4d | %-25.25s | %-40.40s |\n",
                                        $i,
                                        $stat[0],
                                        implode( " ", array_slice( $stat, 1 ) )
                                );
                                $i += 1;
                        }
                        $out .= $hdr;
                };
                return $out;
        }
}