diff options
Diffstat (limited to 'wp-includes/plugin.php')
| -rw-r--r-- | wp-includes/plugin.php | 229 |
1 files changed, 203 insertions, 26 deletions
diff --git a/wp-includes/plugin.php b/wp-includes/plugin.php index 385c569..42dde27 100644 --- a/wp-includes/plugin.php +++ b/wp-includes/plugin.php @@ -1,27 +1,79 @@ <?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. + * + * For static methods (you won't have access to the <tt>$this</tt> variable in the + * method): + * <code>array('class_name', 'method_name');</code> + * + * The second method will need the reference to the object to have access to the + * method. + * <code>array(&$this, 'method_name');</code> + * <code> + * $obj = new myObject(); + * array(&$obj, 'method_name'); + * </code> + * 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. + * 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 1.5 + * @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[ $tag ] ); return true; } @@ -33,20 +85,35 @@ function add_filter($tag, $function_to_add, $priority = 10, $accepted_args = 1) * calling this function. This function can be used to create a new filter hook * by simply calling this function with the name of the new hook specified using * the <tt>$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 + * } + * $value = apply_filters('example_filter', 'filter me', 'arg1', 'arg2'); + * </code> + * + * @package WordPress + * @subpackage Plugin + * @since 1.5 + * @global array $wp_filter Stores all of the filters + * @global array $merge_filters Merges the filter hooks using this function. + * * @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 string $value The value on which the filters hooked to <tt>$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>$string</tt> after all hooked functions are applied to it. */ -function apply_filters($tag, $string) { +function apply_filters($tag, $value) { global $wp_filter, $merged_filters; if ( !isset( $merged_filters[ $tag ] ) ) merge_filters($tag); if ( !isset($wp_filter[$tag]) ) - return $string; + return $value; reset( $wp_filter[ $tag ] ); @@ -55,13 +122,13 @@ function apply_filters($tag, $string) { do{ foreach( (array) current($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; + return $value; } /** @@ -70,7 +137,17 @@ function apply_filters($tag, $string) { * It is possible to defined generic filter functions using the filter hook * <em>all</e>. These functions are called for every filter tag. This function * merges the functions attached to the <em>all</em> hook with the functions - * of a specific hoook defined by <tt>$tag</tt>. + * of a specific hook defined by <tt>$tag</tt>. + * + * Bugged if you hook into 'all' tag, then you <strong>will</strong> lose all priority + * information. {@link http://trac.wordpress.org/ticket/4715 Bug #4715} for more information. + * + * @package WordPress + * @subpackage Plugin + * @since 1.5 + * @global array $wp_filter Stores all of the filters + * @global array $merge_filters Merges the filter hooks using this function. + * * @param string $tag The filter hook of which the functions should be merged. */ function merge_filters($tag) { @@ -92,11 +169,20 @@ function merge_filters($tag) { * This function removes a function attached to a specified filter hook. This * method can be used to remove default functions attached to a specific filter * hook and possibly replace them with a substitute. + * + * To remove a hook, the <tt>$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 1.5 + * * @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, $priority); @@ -117,11 +203,16 @@ function remove_filter($tag, $function_to_remove, $priority = 10, $accepted_args * 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 1.5 + * * @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, $accepted_args); @@ -133,9 +224,21 @@ function add_action($tag, $function_to_add, $priority = 10, $accepted_args = 1) * This function invokes all functions attached to action hook <tt>$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 1.5 + * @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, $wp_actions; @@ -169,6 +272,12 @@ function do_action($tag, $arg = '') { /** * 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 */ @@ -182,12 +291,22 @@ function did_action($tag) { } /** - * Execute functions hooked on a specific action hook, specifying arguments in a array. + * Execute functions hooked on a specific action hook, specifying arguments in an array. * - * This function is identical to {@link do_action}, but the argumetns passe to + * @see do_action() This function is identical, but the arguments passed to * the functions hooked to <tt>$tag</tt> are supplied using an array. + * + * @uses merge_filters() + * + * @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, $wp_actions; @@ -217,6 +336,13 @@ function do_action_ref_array($tag, $args) { * 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. + * + * @uses remove_filter() Uses remove_filter to remove actions added. + * + * @package WordPress + * @subpackage Plugin + * @since 1.5 + * * @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 $priority optional The priority of the function (default: 10). @@ -235,6 +361,13 @@ function remove_action($tag, $function_to_remove, $priority = 10, $accepted_args * 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 $file The filename of plugin. * @return string The name of a plugin. */ @@ -242,7 +375,6 @@ function plugin_basename($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 plugins dir return $file; } @@ -253,10 +385,17 @@ function plugin_basename($file) { * 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 1.5 + * + * @access private + * * @param string $file The filename of the plugin including the path. * @param string $function the function hooked to the 'activate_PLUGIN' action. */ @@ -276,6 +415,13 @@ function register_activation_hook($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 $function the function hooked to the 'activate_PLUGIN' action. */ @@ -284,19 +430,49 @@ function register_deactivation_hook($file, $function) { add_action('deactivate_' . $file, $function); } +/** + * 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 $priority Used in counting how many hooks were applied + * @return string Unique ID for usage as array key + */ function _wp_filter_build_unique_id($tag, $function, $priority = 10) { global $wp_filter; // If function then just skip all of the tests and not overwrite the following. - // Static Calling if( is_string($function) ) return $function; // Object Class Calling else if(is_object($function[0]) ) { $obj_idx = get_class($function[0]).$function[1]; - if( is_null($function[0]->wp_filter_id) ) { + if( is_null($function[0]->wp_filter_id) ) { // This should be instead of is_null() change to !isset() to fix notice $count = count((array)$wp_filter[$tag][$priority]); $function[0]->wp_filter_id = $count; $obj_idx .= $count; @@ -305,6 +481,7 @@ function _wp_filter_build_unique_id($tag, $function, $priority = 10) $obj_idx .= $function[0]->wp_filter_id; return $obj_idx; } + // Static Calling else if( is_string($function[0]) ) return $function[0].$function[1]; } |