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Diffstat (limited to 'wp-includes/plugin.php')
-rw-r--r-- | wp-includes/plugin.php | 448 |
1 files changed, 366 insertions, 82 deletions
diff --git a/wp-includes/plugin.php b/wp-includes/plugin.php index 26b79ca..556570a 100644 --- a/wp-includes/plugin.php +++ b/wp-includes/plugin.php @@ -1,150 +1,294 @@ <?php +/** + * The plugin API is located in this file, which allows for creating actions + * and filters and hooking functions, and methods. The functions or methods will + * then be run when the action or filter is called. + * + * The API callback examples reference functions, but can be methods of classes. + * To hook methods, you'll need to pass an array one of two ways. + * + * Any of the syntaxes explained in the PHP documentation for the + * {@link http://us2.php.net/manual/en/language.pseudo-types.php#language.types.callback 'callback'} + * type are valid. + * + * Also see the {@link http://codex.wordpress.org/Plugin_API Plugin API} for more information + * and examples on how to use a lot of these functions. + * + * @package WordPress + * @subpackage Plugin + * @since 1.5 + */ /** - * Hooks a function to a specific filter action. + * add_filter() - Hooks a function or method to a specific filter action. * * Filters are the hooks that WordPress launches to modify text of various types * before adding it to the database or sending it to the browser screen. Plugins * can specify that one or more of its PHP functions is executed to * modify specific types of text at these times, using the Filter API. - * See the [Plugin API] for a list of filter hooks. + * + * To use the API, the following code should be used to bind a callback to the filter + * <code> + * function example_hook($example) { echo $example; } + * + * add_filter('example_filter', 'example_hook'); + * </code> + * + * In WordPress 1.5.1+, hooked functions can take extra arguments that are set when + * the matching do_action() or apply_filters() call is run. The <tt>$accepted_args + * allow for calling functions only when the number of args match. Hooked functions + * can take extra arguments that are set when the matching <tt>do_action()</tt> or + * <tt>apply_filters()</tt> call is run. For example, the action <tt>comment_id_not_found</tt> + * will pass any functions that hook onto it the ID of the requested comment. + * + * <strong>Note:</strong> the function will return true no matter if the function was hooked + * fails or not. There are no checks for whether the function exists beforehand and no checks + * to whether the <tt>$function_to_add is even a string. It is up to you to take care and + * this is done for optimization purposes, so everything is as quick as possible. + * + * @package WordPress + * @subpackage Plugin + * @since 0.71 + * @global array $wp_filter Stores all of the filters added in the form of + * wp_filter['tag']['array of priorities']['array of functions serialized']['array of ['array (functions, accepted_args)]'] + * @global array $merged_filters Tracks the tags that need to be merged for later. If the hook is added, it doesn't need to run through that process. * * @param string $tag The name of the filter to hook the <tt>$function_to_add</tt> to. * @param callback $function_to_add The name of the function to be called when the filter is applied. * @param int $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default: 10). Lower numbers correspond with earlier execution, and functions with the same priority are executed in the order in which they were added to the action. - * @param int $accepted_args optional. The number of arguments the function accept (default 1). In WordPress 1.5.1+, hooked functions can take extra arguments that are set when the matching do_action() or apply_filters() call is run. - * @return boolean true if the <tt>$function_to_add</tt> is added succesfully to filter <tt>$tag</tt>. How many arguments your function takes. In WordPress 1.5.1+, hooked functions can take extra arguments that are set when the matching <tt>do_action()</tt> or <tt>apply_filters()</tt> call is run. For example, the action <tt>comment_id_not_found</tt> will pass any functions that hook onto it the ID of the requested comment. + * @param int $accepted_args optional. The number of arguments the function accept (default 1). + * @return boolean true */ function add_filter($tag, $function_to_add, $priority = 10, $accepted_args = 1) { global $wp_filter, $merged_filters; - // So the format is wp_filter['tag']['array of priorities']['array of functions serialized']['array of ['array (functions, accepted_args)]'] $idx = _wp_filter_build_unique_id($tag, $function_to_add, $priority); - $wp_filter[$tag][$priority][$idx] = array('function' => $function_to_add, 'accepted_args' => $accepted_args); - //$wp_filter[$tag][$priority][serialize($function_to_add)] = array('function' => $function_to_add, 'accepted_args' => $accepted_args); + $wp_filter[$tag][$priority][$idx] = array('function' => $function_to_add, 'accepted_args' => $accepted_args); unset( $merged_filters[ $tag ] ); return true; } /** - * Call the functions added to a filter hook. + * has_filter() - Check if any filter has been registered for a hook. + * + * @package WordPress + * @subpackage Plugin + * @since 2.5 + * @global array $wp_filter Stores all of the filters + * + * @param string $tag The name of the filter hook. + * @param callback $function_to_check optional. If specified, return the priority of that function on this hook or false if not attached. + * @return int|boolean Optionally returns the priority on that hook for the specified function. + */ +function has_filter($tag, $function_to_check = false) { + global $wp_filter; + + $has = !empty($wp_filter[$tag]); + if ( false === $function_to_check || false == $has ) + return $has; + + if ( !$idx = _wp_filter_build_unique_id($tag, $function_to_check, false) ) + return false; + + foreach ( array_keys($wp_filter[$tag]) as $priority ) { + if ( isset($wp_filter[$tag][$priority][$idx]) ) + return $priority; + } + + return false; +} + +/** + * apply_filters() - Call the functions added to a filter hook. * * The callback functions attached to filter hook <tt>$tag</tt> are invoked by * calling this function. This function can be used to create a new filter hook * by simply calling this function with the name of the new hook specified using * the <tt>$tag</a> parameter. - * @uses merge_filters Merges the filter hooks using this function. + * + * The function allows for additional arguments to be added and passed to hooks. + * <code> + * function example_hook($string, $arg1, $arg2) + * { + * //Do stuff + * return $string; + * } + * $value = apply_filters('example_filter', 'filter me', 'arg1', 'arg2'); + * </code> + * + * @package WordPress + * @subpackage Plugin + * @since 0.71 + * @global array $wp_filter Stores all of the filters + * @global array $merge_filters Merges the filter hooks using this function. + * @global array $wp_current_filter stores the list of current filters with the current one last + * * @param string $tag The name of the filter hook. - * @param string $string The text on which the filters hooked to <tt>$tag</tt> are applied on. + * @param mixed $value The value on which the filters hooked to <tt>$tag</tt> are applied on. * @param mixed $var,... Additional variables passed to the functions hooked to <tt>$tag</tt>. - * @return string The text in <tt>$string</tt> after all hooked functions are applied to it. + * @return mixed The filtered value after all hooked functions are applied to it. */ -function apply_filters($tag, $string) { - global $wp_filter, $merged_filters; +function apply_filters($tag, $value) { + global $wp_filter, $merged_filters, $wp_current_filter; - if ( !isset( $merged_filters[ $tag ] ) ) - merge_filters($tag); + $args = array(); + $wp_current_filter[] = $tag; + + // Do 'all' actions first + if ( isset($wp_filter['all']) ) { + $args = func_get_args(); + _wp_call_all_hook($args); + } - if ( !isset($wp_filter[$tag]) ) - return $string; + if ( !isset($wp_filter[$tag]) ) { + array_pop($wp_current_filter); + return $value; + } + + // Sort + if ( !isset( $merged_filters[ $tag ] ) ) { + ksort($wp_filter[$tag]); + $merged_filters[ $tag ] = true; + } reset( $wp_filter[ $tag ] ); - $args = func_get_args(); + if ( empty($args) ) + $args = func_get_args(); - do{ + do { foreach( (array) current($wp_filter[$tag]) as $the_ ) if ( !is_null($the_['function']) ){ - $args[1] = $string; - $string = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args'])); + $args[1] = $value; + $value = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args'])); } } while ( next($wp_filter[$tag]) !== false ); - return $string; -} - -/** - * Merge the filter functions of a specific filter hook with generic filter functions. - * - * It is possible to defined generic filter functions using the filter hook - * <em>all</e>. These functions are called for every filter tag. This function - * merges the functions attached to the <em>all</em> hook with the functions - * of a specific hoook defined by <tt>$tag</tt>. - * @param string $tag The filter hook of which the functions should be merged. - */ -function merge_filters($tag) { - global $wp_filter, $merged_filters; - - if ( isset($wp_filter['all']) && is_array($wp_filter['all']) ) - $wp_filter[$tag] = array_merge($wp_filter['all'], (array) $wp_filter[$tag]); + array_pop( $wp_current_filter ); - if ( isset($wp_filter[$tag]) ){ - reset($wp_filter[$tag]); - uksort($wp_filter[$tag], "strnatcasecmp"); - } - $merged_filters[ $tag ] = true; + return $value; } /** - * Removes a function from a specified filter hook. + * remove_filter() - Removes a function from a specified filter hook. * * This function removes a function attached to a specified filter hook. This * method can be used to remove default functions attached to a specific filter * hook and possibly replace them with a substitute. + * + * To remove a hook, the <tt>$function_to_remove</tt> and <tt>$priority</tt> arguments + * must match when the hook was added. This goes for both filters and actions. No warning + * will be given on removal failure. + * + * @package WordPress + * @subpackage Plugin + * @since 1.2 + * * @param string $tag The filter hook to which the function to be removed is hooked. * @param callback $function_to_remove The name of the function which should be removed. * @param int $priority optional. The priority of the function (default: 10). * @param int $accepted_args optional. The number of arguments the function accpets (default: 1). - * @return boolean Whether the function is removed. + * @return boolean Whether the function existed before it was removed. */ function remove_filter($tag, $function_to_remove, $priority = 10, $accepted_args = 1) { $function_to_remove = _wp_filter_build_unique_id($tag, $function_to_remove, $priority); $r = isset($GLOBALS['wp_filter'][$tag][$priority][$function_to_remove]); - unset($GLOBALS['wp_filter'][$tag][$priority][$function_to_remove]); - unset($GLOBALS['merged_filters'][$tag]); + if ( true === $r) { + unset($GLOBALS['wp_filter'][$tag][$priority][$function_to_remove]); + if ( empty($GLOBALS['wp_filter'][$tag][$priority]) ) + unset($GLOBALS['wp_filter'][$tag][$priority]); + unset($GLOBALS['merged_filters'][$tag]); + } return $r; } + /** - * Hooks a function on to a specific action. + * current_filter() - Return the name of the current filter or action. + * + * @package WordPress + * @subpackage Plugin + * @since 2.5 + * + * @return string Hook name of the current filter or action. + */ +function current_filter() { + global $wp_current_filter; + return end( $wp_current_filter ); +} + + +/** + * add_action() - Hooks a function on to a specific action. * * Actions are the hooks that the WordPress core launches at specific points * during execution, or when specific events occur. Plugins can specify that * one or more of its PHP functions are executed at these points, using the * Action API. * + * @uses add_filter() Adds an action. Parameter list and functionality are the same. + * + * @package WordPress + * @subpackage Plugin + * @since 1.2 + * * @param string $tag The name of the action to which the <tt>$function_to-add</tt> is hooked. - * @param callback $function_to_add The name of the function you wish to be called. Note: any of the syntaxes explained in the PHP documentation for the 'callback' type (http://us2.php.net/manual/en/language.pseudo-types.php#language.types.callback) are valid. + * @param callback $function_to_add The name of the function you wish to be called. * @param int $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default: 10). Lower numbers correspond with earlier execution, and functions with the same priority are executed in the order in which they were added to the action. - * @param int $accepted_args optional. The number of arguments the function accept (default 1). In WordPress 1.5.1+, hooked functions can take extra arguments that are set when the matching do_action() or apply_filters() call is run. - * @return boolean Always true. + * @param int $accepted_args optional. The number of arguments the function accept (default 1). */ function add_action($tag, $function_to_add, $priority = 10, $accepted_args = 1) { - add_filter($tag, $function_to_add, $priority, $accepted_args); + return add_filter($tag, $function_to_add, $priority, $accepted_args); } + /** - * Execute functions hooked on a specific action hook. + * do_action() - Execute functions hooked on a specific action hook. * * This function invokes all functions attached to action hook <tt>$tag</tt>. * It is possible to create new action hooks by simply calling this function, * specifying the name of the new hook using the <tt>$tag</tt> parameter. - * @uses merge_filters + * + * You can pass extra arguments to the hooks, much like you can with apply_filters(). + * + * @see apply_filters() This function works similar with the exception that nothing is + * returned and only the functions or methods are called. + * + * @package WordPress + * @subpackage Plugin + * @since 1.2 + * @global array $wp_filter Stores all of the filters + * @global array $wp_actions Increments the amount of times action was triggered. + * * @param string $tag The name of the action to be executed. * @param mixed $arg,... Optional additional arguments which are passed on to the functions hooked to the action. + * @return null Will return null if $tag does not exist in $wp_filter array */ function do_action($tag, $arg = '') { - global $wp_filter, $wp_actions; + global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter; if ( is_array($wp_actions) ) $wp_actions[] = $tag; else $wp_actions = array($tag); + $wp_current_filter[] = $tag; + + // Do 'all' actions first + if ( isset($wp_filter['all']) ) { + $all_args = func_get_args(); + _wp_call_all_hook($all_args); + } + + if ( !isset($wp_filter[$tag]) ) { + array_pop($wp_current_filter); + return; + } + $args = array(); if ( is_array($arg) && 1 == count($arg) && is_object($arg[0]) ) // array(&$this) $args[] =& $arg[0]; @@ -153,22 +297,32 @@ function do_action($tag, $arg = '') { for ( $a = 2; $a < func_num_args(); $a++ ) $args[] = func_get_arg($a); - merge_filters($tag); + // Sort + if ( !isset( $merged_filters[ $tag ] ) ) { + ksort($wp_filter[$tag]); + $merged_filters[ $tag ] = true; + } - if ( !isset($wp_filter[$tag]) ) - return; + reset( $wp_filter[ $tag ] ); - do{ - foreach( (array) current($wp_filter[$tag]) as $the_ ) + do { + foreach ( (array) current($wp_filter[$tag]) as $the_ ) if ( !is_null($the_['function']) ) call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args'])); } while ( next($wp_filter[$tag]) !== false ); + array_pop($wp_current_filter); } /** - * Return the number times an action is fired. + * did_action() - Return the number times an action is fired. + * + * @package WordPress + * @subpackage Plugin + * @since 2.1 + * @global array $wp_actions Increments the amount of times action was triggered. + * * @param string $tag The name of the action hook. * @return int The number of times action hook <tt>$tag</tt> is fired */ @@ -182,41 +336,87 @@ function did_action($tag) { } /** - * Execute functions hooked on a specific action hook, specifying arguments in a array. + * do_action_ref_array() - Execute functions hooked on a specific action hook, specifying arguments in an array. * - * This function is identical to {@link do_action}, but the argumetns passe to + * @see do_action() This function is identical, but the arguments passed to * the functions hooked to <tt>$tag</tt> are supplied using an array. + * + * @package WordPress + * @subpackage Plugin + * @since 2.1 + * @global array $wp_filter Stores all of the filters + * @global array $wp_actions Increments the amount of times action was triggered. + * * @param string $tag The name of the action to be executed. * @param array $args The arguments supplied to the functions hooked to <tt>$tag</tt> + * @return null Will return null if $tag does not exist in $wp_filter array */ function do_action_ref_array($tag, $args) { - global $wp_filter, $wp_actions; + global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter; if ( !is_array($wp_actions) ) $wp_actions = array($tag); else $wp_actions[] = $tag; - merge_filters($tag); + $wp_current_filter[] = $tag; + + // Do 'all' actions first + if ( isset($wp_filter['all']) ) { + $all_args = func_get_args(); + _wp_call_all_hook($all_args); + } - if ( !isset($wp_filter[$tag]) ) + if ( !isset($wp_filter[$tag]) ) { + array_pop($wp_current_filter); return; + } - do{ + // Sort + if ( !isset( $merged_filters[ $tag ] ) ) { + ksort($wp_filter[$tag]); + $merged_filters[ $tag ] = true; + } + + reset( $wp_filter[ $tag ] ); + + do { foreach( (array) current($wp_filter[$tag]) as $the_ ) if ( !is_null($the_['function']) ) call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args'])); } while ( next($wp_filter[$tag]) !== false ); + array_pop($wp_current_filter); +} + +/** + * has_action() - Check if any action has been registered for a hook. + * + * @package WordPress + * @subpackage Plugin + * @since 2.5 + * @see has_filter() has_action() is an alias of has_filter(). + * + * @param string $tag The name of the action hook. + * @param callback $function_to_check optional. If specified, return the priority of that function on this hook or false if not attached. + * @return int|boolean Optionally returns the priority on that hook for the specified function. + */ +function has_action($tag, $function_to_check = false) { + return has_filter($tag, $function_to_check); } /** - * Removes a function from a specified action hook. + * remove_action() - Removes a function from a specified action hook. * * This function removes a function attached to a specified action hook. This * method can be used to remove default functions attached to a specific filter * hook and possibly replace them with a substitute. + * + * @package WordPress + * @subpackage Plugin + * @since 1.2 + * * @param string $tag The action hook to which the function to be removed is hooked. * @param callback $function_to_remove The name of the function which should be removed. * @param int $priority optional The priority of the function (default: 10). @@ -232,31 +432,44 @@ function remove_action($tag, $function_to_remove, $priority = 10, $accepted_args // /** - * Gets the basename of a plugin. + * plugin_basename() - Gets the basename of a plugin. * * This method extract the name of a plugin from its filename. + * + * @package WordPress + * @subpackage Plugin + * @since 1.5 + * + * @access private + * * @param string $file The filename of plugin. * @return string The name of a plugin. */ function plugin_basename($file) { $file = str_replace('\\','/',$file); // sanitize for Win32 installs $file = preg_replace('|/+|','/', $file); // remove any duplicate slash - $file = preg_replace('|^.*/wp-content/plugins/|','',$file); // get relative path from plugins dir - $file = preg_replace('|^.*/wp-content/mu-plugins/|','',$file); // get relative path from mu-plugins dir + $file = preg_replace('|^.*/' . PLUGINDIR . '/|','',$file); // get relative path from plugins dir return $file; } /** - * Hook a function on a plugin activation action hook. + * register_activation_hook() - Hook a function on a plugin activation action hook. * * When a plugin is activated, the action 'activate_PLUGINNAME' hook is * activated. In the name of this hook, PLUGINNAME is replaced with the name of * the plugin, including the optional subdirectory. For example, when the plugin * is located in <tt>wp-content/plugin/sampleplugin/sample.php</tt>, then the - * name of this hook will become 'activate_sampleplugin/sample.php'. + * name of this hook will become 'activate_sampleplugin/sample.php' * When the plugin consists of only one file and is (as by default) located at * <tt>wp-content/plugin/sample.php</tt> the name of this hook will be * 'activate_sample.php'. + * + * @package WordPress + * @subpackage Plugin + * @since 2.0 + * + * @access private + * * @param string $file The filename of the plugin including the path. * @param string $function the function hooked to the 'activate_PLUGIN' action. */ @@ -266,7 +479,7 @@ function register_activation_hook($file, $function) { } /** - * Hook a function on a plugin deactivation action hook. + * register_deactivation_hook() - Hook a function on a plugin deactivation action hook. * * When a plugin is deactivated, the action 'deactivate_PLUGINNAME' hook is * deactivated. In the name of this hook, PLUGINNAME is replaced with the name of @@ -276,6 +489,13 @@ function register_activation_hook($file, $function) { * When the plugin consists of only one file and is (as by default) located at * <tt>wp-content/plugin/sample.php</tt> the name of this hook will be * 'activate_sample.php'. + * + * @package WordPress + * @subpackage Plugin + * @since 2.0 + * + * @access private + * * @param string $file The filename of the plugin including the path. * @param string $function the function hooked to the 'activate_PLUGIN' action. */ @@ -284,19 +504,82 @@ function register_deactivation_hook($file, $function) { add_action('deactivate_' . $file, $function); } -function _wp_filter_build_unique_id($tag, $function, $priority = 10) -{ +/** + * _wp_call_all_hook() - Calls the 'all' hook, which will process the functions hooked into it. + * + * The 'all' hook passes all of the arguments or parameters that were used for the + * hook, which this function was called for. + * + * This function is used internally for apply_filters(), do_action(), and do_action_ref_array() + * and is not meant to be used from outside those functions. This function does not check for the + * existence of the all hook, so it will fail unless the all hook exists prior to this function call. + * + * @package WordPress + * @subpackage Plugin + * @since 2.5 + * @access private + * + * @uses $wp_filter Used to process all of the functions in the 'all' hook + * + * @param array $args The collected parameters from the hook that was called. + * @param string $hook Optional. The hook name that was used to call the 'all' hook. + */ +function _wp_call_all_hook($args) { + global $wp_filter; + + reset( $wp_filter['all'] ); + do { + foreach( (array) current($wp_filter['all']) as $the_ ) + if ( !is_null($the_['function']) ) + call_user_func_array($the_['function'], $args); + + } while ( next($wp_filter['all']) !== false ); +} + +/** + * _wp_filter_build_unique_id() - Build Unique ID for storage and retrieval + * + * The old way to serialize the callback caused issues and this function is the + * solution. It works by checking for objects and creating an a new property in + * the class to keep track of the object and new objects of the same class that + * need to be added. + * + * It also allows for the removal of actions and filters for objects after they + * change class properties. It is possible to include the property $wp_filter_id + * in your class and set it to "null" or a number to bypass the workaround. However + * this will prevent you from adding new classes and any new classes will overwrite + * the previous hook by the same class. + * + * Functions and static method callbacks are just returned as strings and shouldn't + * have any speed penalty. + * + * @package WordPress + * @subpackage Plugin + * @since 2.2.3 + * + * @link http://trac.wordpress.org/ticket/3875 + * + * @access private + * + * @global array $wp_filter Storage for all of the filters and actions + * @param string $tag Used in counting how many hooks were applied + * @param string|array $function Used for creating unique id + * @param int|bool $priority Used in counting how many hooks were applied. If === false and $function is an object reference, we return the unique id only if it already has one, false otherwise. + * @param string $type filter or action + * @return string Unique ID for usage as array key + */ +function _wp_filter_build_unique_id($tag, $function, $priority) { global $wp_filter; // If function then just skip all of the tests and not overwrite the following. - // Static Calling - if( is_string($function) ) + if ( is_string($function) ) return $function; // Object Class Calling - else if(is_object($function[0]) ) - { + else if (is_object($function[0]) ) { $obj_idx = get_class($function[0]).$function[1]; - if( is_null($function[0]->wp_filter_id) ) { + if ( !isset($function[0]->wp_filter_id) ) { + if ( false === $priority ) + return false; $count = count((array)$wp_filter[$tag][$priority]); $function[0]->wp_filter_id = $count; $obj_idx .= $count; @@ -305,7 +588,8 @@ function _wp_filter_build_unique_id($tag, $function, $priority = 10) $obj_idx .= $function[0]->wp_filter_id; return $obj_idx; } - else if( is_string($function[0]) ) + // Static Calling + else if ( is_string($function[0]) ) return $function[0].$function[1]; } |