diff options
author | Yaco <franco@reevo.org> | 2020-06-04 11:01:00 -0300 |
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committer | Yaco <franco@reevo.org> | 2020-06-04 11:01:00 -0300 |
commit | fc7369835258467bf97eb64f184b93691f9a9fd5 (patch) | |
tree | daabd60089d2dd76d9f5fb416b005fbe159c799d /www/wiki/includes/Hooks.php |
first commit
Diffstat (limited to 'www/wiki/includes/Hooks.php')
-rw-r--r-- | www/wiki/includes/Hooks.php | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/www/wiki/includes/Hooks.php b/www/wiki/includes/Hooks.php new file mode 100644 index 00000000..c22dc97f --- /dev/null +++ b/www/wiki/includes/Hooks.php @@ -0,0 +1,244 @@ +<?php + +/** + * A tool for running hook functions. + * + * Copyright 2004, 2005 Evan Prodromou <evan@wikitravel.org>. + * + * 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 + * + * @author Evan Prodromou <evan@wikitravel.org> + * @see hooks.txt + * @file + */ + +/** + * Hooks class. + * + * Used to supersede $wgHooks, because globals are EVIL. + * + * @since 1.18 + */ +class Hooks { + /** + * Array of events mapped to an array of callbacks to be run + * when that event is triggered. + */ + protected static $handlers = []; + + /** + * Attach an event handler to a given hook. + * + * @param string $name Name of hook + * @param callable $callback Callback function to attach + * + * @since 1.18 + */ + public static function register( $name, $callback ) { + if ( !isset( self::$handlers[$name] ) ) { + self::$handlers[$name] = []; + } + + self::$handlers[$name][] = $callback; + } + + /** + * Clears hooks registered via Hooks::register(). Does not touch $wgHooks. + * This is intended for use while testing and will fail if MW_PHPUNIT_TEST is not defined. + * + * @param string $name The name of the hook to clear. + * + * @since 1.21 + * @throws MWException If not in testing mode. + */ + public static function clear( $name ) { + if ( !defined( 'MW_PHPUNIT_TEST' ) && !defined( 'MW_PARSER_TEST' ) ) { + throw new MWException( 'Cannot reset hooks in operation.' ); + } + + unset( self::$handlers[$name] ); + } + + /** + * Returns true if a hook has a function registered to it. + * The function may have been registered either via Hooks::register or in $wgHooks. + * + * @since 1.18 + * + * @param string $name Name of hook + * @return bool True if the hook has a function registered to it + */ + public static function isRegistered( $name ) { + global $wgHooks; + return !empty( $wgHooks[$name] ) || !empty( self::$handlers[$name] ); + } + + /** + * Returns an array of all the event functions attached to a hook + * This combines functions registered via Hooks::register and with $wgHooks. + * + * @since 1.18 + * + * @param string $name Name of the hook + * @return array + */ + public static function getHandlers( $name ) { + global $wgHooks; + + if ( !self::isRegistered( $name ) ) { + return []; + } elseif ( !isset( self::$handlers[$name] ) ) { + return $wgHooks[$name]; + } elseif ( !isset( $wgHooks[$name] ) ) { + return self::$handlers[$name]; + } else { + return array_merge( self::$handlers[$name], $wgHooks[$name] ); + } + } + + /** + * @param string $event Event name + * @param array|callable $hook + * @param array $args Array of parameters passed to hook functions + * @param string|null $deprecatedVersion [optional] + * @param string &$fname [optional] Readable name of hook [returned] + * @return null|string|bool + */ + private static function callHook( $event, $hook, array $args, $deprecatedVersion = null, + &$fname = null + ) { + // Turn non-array values into an array. (Can't use casting because of objects.) + if ( !is_array( $hook ) ) { + $hook = [ $hook ]; + } + + if ( !array_filter( $hook ) ) { + // Either array is empty or it's an array filled with null/false/empty. + return null; + } + + if ( is_array( $hook[0] ) ) { + // First element is an array, meaning the developer intended + // the first element to be a callback. Merge it in so that + // processing can be uniform. + $hook = array_merge( $hook[0], array_slice( $hook, 1 ) ); + } + + /** + * $hook can be: a function, an object, an array of $function and + * $data, an array of just a function, an array of object and + * method, or an array of object, method, and data. + */ + if ( $hook[0] instanceof Closure ) { + $fname = "hook-$event-closure"; + $callback = array_shift( $hook ); + } elseif ( is_object( $hook[0] ) ) { + $object = array_shift( $hook ); + $method = array_shift( $hook ); + + // If no method was specified, default to on$event. + if ( $method === null ) { + $method = "on$event"; + } + + $fname = get_class( $object ) . '::' . $method; + $callback = [ $object, $method ]; + } elseif ( is_string( $hook[0] ) ) { + $fname = $callback = array_shift( $hook ); + } else { + throw new MWException( 'Unknown datatype in hooks for ' . $event . "\n" ); + } + + // Run autoloader (workaround for call_user_func_array bug) + // and throw error if not callable. + if ( !is_callable( $callback ) ) { + throw new MWException( 'Invalid callback ' . $fname . ' in hooks for ' . $event . "\n" ); + } + + // mark hook as deprecated, if deprecation version is specified + if ( $deprecatedVersion !== null ) { + wfDeprecated( "$event hook (used in $fname)", $deprecatedVersion ); + } + + // Call the hook. + $hook_args = array_merge( $hook, $args ); + return call_user_func_array( $callback, $hook_args ); + } + + /** + * Call hook functions defined in Hooks::register and $wgHooks. + * + * For the given hook event, fetch the array of hook events and + * process them. Determine the proper callback for each hook and + * then call the actual hook using the appropriate arguments. + * Finally, process the return value and return/throw accordingly. + * + * For hook event that are not abortable through a handler's return value, + * use runWithoutAbort() instead. + * + * @param string $event Event name + * @param array $args Array of parameters passed to hook functions + * @param string|null $deprecatedVersion [optional] Mark hook as deprecated with version number + * @return bool True if no handler aborted the hook + * + * @throws Exception + * @throws FatalError + * @throws MWException + * @since 1.22 A hook function is not required to return a value for + * processing to continue. Not returning a value (or explicitly + * returning null) is equivalent to returning true. + */ + public static function run( $event, array $args = [], $deprecatedVersion = null ) { + foreach ( self::getHandlers( $event ) as $hook ) { + $retval = self::callHook( $event, $hook, $args, $deprecatedVersion ); + if ( $retval === null ) { + continue; + } + + // Process the return value. + if ( is_string( $retval ) ) { + // String returned means error. + throw new FatalError( $retval ); + } elseif ( $retval === false ) { + // False was returned. Stop processing, but no error. + return false; + } + } + + return true; + } + + /** + * Call hook functions defined in Hooks::register and $wgHooks. + * + * @param string $event Event name + * @param array $args Array of parameters passed to hook functions + * @param string|null $deprecatedVersion [optional] Mark hook as deprecated with version number + * @return bool Always true + * @throws MWException If a callback is invalid, unknown + * @throws UnexpectedValueException If a callback returns an abort value. + * @since 1.30 + */ + public static function runWithoutAbort( $event, array $args = [], $deprecatedVersion = null ) { + foreach ( self::getHandlers( $event ) as $hook ) { + $fname = null; + $retval = self::callHook( $event, $hook, $args, $deprecatedVersion, $fname ); + if ( $retval !== null && $retval !== true ) { + throw new UnexpectedValueException( "Invalid return from $fname for unabortable $event." ); + } + } + return true; + } +} |