add_filter( $tag, $function_to_add, $priority, $accepted_args ); return true; } /** * Check if any filter has been registered for a hook. * * @since 2.5.0 * * @global array $wp_filter Stores all of the filters. * * @param string $tag The name of the filter hook. * @param callable|bool $function_to_check Optional. The callback to check for. Default false. * @return false|int If $function_to_check is omitted, returns boolean for whether the hook has * anything registered. When checking a specific function, the priority of that * hook is returned, or false if the function is not attached. When using the * $function_to_check argument, this function may return a non-boolean value * that evaluates to false (e.g.) 0, so use the === operator for testing the * return value. */ function has_filter( $tag, $function_to_check = false ) { global $wp_filter; if ( ! isset( $wp_filter[ $tag ] ) ) { return false; } return $wp_filter[ $tag ]->has_filter( $tag, $function_to_check ); } /** * Calls the callback functions that have been added to a filter hook. * * The callback functions attached to the filter hook are invoked by calling * this function. This function can be used to create a new filter hook by * simply calling this function with the name of the new hook specified using * the `$tag` parameter. * * The function also allows for multiple additional arguments to be passed to hooks. * * Example usage: * * // The filter callback function * function example_callback( $string, $arg1, $arg2 ) { * // (maybe) modify $string * return $string; * } * add_filter( 'example_filter', 'example_callback', 10, 3 ); * * /* * * Apply the filters by calling the 'example_callback()' function that's * * hooked onto `example_filter` above. * * * * - 'example_filter' is the filter hook * * - 'filter me' is the value being filtered * * - $arg1 and $arg2 are the additional arguments passed to the callback. * $value = apply_filters( 'example_filter', 'filter me', $arg1, $arg2 ); * * @since 0.71 * * @global array $wp_filter Stores all of the filters. * @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 mixed $value The value to filter. * @param mixed ...$args Additional parameters to pass to the callback functions. * @return mixed The filtered value after all hooked functions are applied to it. */ function apply_filters( $tag, $value ) { global $wp_filter, $wp_current_filter; $args = func_get_args(); // Do 'all' actions first. if ( isset( $wp_filter['all'] ) ) { $wp_current_filter[] = $tag; _wp_call_all_hook( $args ); } if ( ! isset( $wp_filter[ $tag ] ) ) { if ( isset( $wp_filter['all'] ) ) { array_pop( $wp_current_filter ); } return $value; } if ( ! isset( $wp_filter['all'] ) ) { $wp_current_filter[] = $tag; } // Don't pass the tag name to WP_Hook. array_shift( $args ); $filtered = $wp_filter[ $tag ]->apply_filters( $value, $args ); array_pop( $wp_current_filter ); return $filtered; } /** * Calls the callback functions that have been added to a filter hook, specifying arguments in an array. * * @since 3.0.0 * * @see apply_filters() This function is identical, but the arguments passed to the * functions hooked to `$tag` are supplied using an array. * * @global array $wp_filter Stores all of the filters * @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 array $args The arguments supplied to the functions hooked to $tag. * @return mixed The filtered value after all hooked functions are applied to it. */ function apply_filters_ref_array( $tag, $args ) { global $wp_filter, $wp_current_filter; // Do 'all' actions first if ( isset( $wp_filter['all'] ) ) { $wp_current_filter[] = $tag; $all_args = func_get_args(); _wp_call_all_hook( $all_args ); } if ( ! isset( $wp_filter[ $tag ] ) ) { if ( isset( $wp_filter['all'] ) ) { array_pop( $wp_current_filter ); } return $args[0]; } if ( ! isset( $wp_filter['all'] ) ) { $wp_current_filter[] = $tag; } $filtered = $wp_filter[ $tag ]->apply_filters( $args[0], $args ); array_pop( $wp_current_filter ); return $filtered; } /** * 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 $function_to_remove and $priority arguments must match * when the hook was added. This goes for both filters and actions. No warning * will be given on removal failure. * * @since 1.2.0 * * @global array $wp_filter Stores all of the filters * * @param string $tag The filter hook to which the function to be removed is hooked. * @param callable $function_to_remove The name of the function which should be removed. * @param int $priority Optional. The priority of the function. Default 10. * @return bool Whether the function existed before it was removed. */ function remove_filter( $tag, $function_to_remove, $priority = 10 ) { global $wp_filter; $r = false; if ( isset( $wp_filter[ $tag ] ) ) { $r = $wp_filter[ $tag ]->remove_filter( $tag, $function_to_remove, $priority ); if ( ! $wp_filter[ $tag ]->callbacks ) { unset( $wp_filter[ $tag ] ); } } return $r; } /** * Remove all of the hooks from a filter. * * @since 2.7.0 * * @global array $wp_filter Stores all of the filters * * @param string $tag The filter to remove hooks from. * @param int|bool $priority Optional. The priority number to remove. Default false. * @return true True when finished. */ function remove_all_filters( $tag, $priority = false ) { global $wp_filter; if ( isset( $wp_filter[ $tag ] ) ) { $wp_filter[ $tag ]->remove_all_filters( $priority ); if ( ! $wp_filter[ $tag ]->has_filters() ) { unset( $wp_filter[ $tag ] ); } } return true; } /** * Retrieve the name of the current filter or action. * * @since 2.5.0 * * @global array $wp_current_filter Stores the list of current filters with the current one last * * @return string Hook name of the current filter or action. */ function current_filter() { global $wp_current_filter; return end( $wp_current_filter ); } /** * Retrieve the name of the current action. * * @since 3.9.0 * * @return string Hook name of the current action. */ function current_action() { return current_filter(); } /** * Retrieve the name of a filter currently being processed. * * The function current_filter() only returns the most recent filter or action * being executed. did_action() returns true once the action is initially * processed. * * This function allows detection for any filter currently being * executed (despite not being the most recent filter to fire, in the case of * hooks called from hook callbacks) to be verified. * * @since 3.9.0 * * @see current_filter() * @see did_action() * @global array $wp_current_filter Current filter. * * @param null|string $filter Optional. Filter to check. Defaults to null, which * checks if any filter is currently being run. * @return bool Whether the filter is currently in the stack. */ function doing_filter( $filter = null ) { global $wp_current_filter; if ( null === $filter ) { return ! empty( $wp_current_filter ); } return in_array( $filter, $wp_current_filter ); } /** * Retrieve the name of an action currently being processed. * * @since 3.9.0 * * @param string|null $action Optional. Action to check. Defaults to null, which checks * if any action is currently being run. * @return bool Whether the action is currently in the stack. */ function doing_action( $action = null ) { return doing_filter( $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. * * @since 1.2.0 * * @param string $tag The name of the action to which the $function_to_add is hooked. * @param callable $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 accepts. Default 1. * @return true Will always return true. */ function add_action( $tag, $function_to_add, $priority = 10, $accepted_args = 1 ) { return add_filter( $tag, $function_to_add, $priority, $accepted_args ); } /** * Execute functions hooked on a specific action hook. * * This function invokes all functions attached to action hook `$tag`. It is * possible to create new action hooks by simply calling this function, * specifying the name of the new hook using the `$tag` parameter. * * You can pass extra arguments to the hooks, much like you can with `apply_filters()`. * * Example usage: * * // The action callback function * function example_callback( $arg1, $arg2 ) { * // (maybe) do something with the args * } * add_action( 'example_action', 'example_callback', 10, 2 ); * * /* * * Trigger the actions by calling the 'example_callback()' function that's * * hooked onto `example_action` above. * * * * - 'example_action' is the action hook * * - $arg1 and $arg2 are the additional arguments passed to the callback. * $value = do_action( 'example_action', $arg1, $arg2 ); * * @since 1.2.0 * @since 5.3.0 Formalized the existing and already documented `...$arg` parameter * by adding it to the function signature. * * @global array $wp_filter Stores all of the filters * @global array $wp_actions Increments the amount of times action was triggered. * @global array $wp_current_filter Stores the list of current filters with the current one last * * @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. Default empty. */ function do_action( $tag, ...$arg ) { global $wp_filter, $wp_actions, $wp_current_filter; if ( ! isset( $wp_actions[ $tag ] ) ) { $wp_actions[ $tag ] = 1; } else { ++$wp_actions[ $tag ]; } // Do 'all' actions first if ( isset( $wp_filter['all'] ) ) { $wp_current_filter[] = $tag; $all_args = func_get_args(); _wp_call_all_hook( $all_args ); } if ( ! isset( $wp_filter[ $tag ] ) ) { if ( isset( $wp_filter['all'] ) ) { array_pop( $wp_current_filter ); } return; } if ( ! isset( $wp_filter['all'] ) ) { $wp_current_filter[] = $tag; } if ( empty( $arg ) ) { $arg[] = ''; } elseif ( is_array( $arg[0] ) && 1 === count( $arg[0] ) && isset( $arg[0][0] ) && is_object( $arg[0][0] ) ) { // Backward compatibility for PHP4-style passing of `array( &$this )` as action `$arg`. $arg[0] = $arg[0][0]; } $wp_filter[ $tag ]->do_action( $arg ); array_pop( $wp_current_filter ); } /** * Retrieve the number of times an action is fired. * * @since 2.1.0 * * @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 $tag is fired. */ function did_action( $tag ) { global $wp_actions; if ( ! isset( $wp_actions[ $tag ] ) ) { return 0; } return $wp_actions[ $tag ]; } /** * Calls the callback functions that have been added to an action hook, specifying arguments in an array. * * @since 2.1.0 * * @see do_action() This function is identical, but the arguments passed to the * functions hooked to `$tag` are supplied using an array. * @global array $wp_filter Stores all of the filters * @global array $wp_actions Increments the amount of times action was triggered. * @global array $wp_current_filter Stores the list of current filters with the current one last * * @param string $tag The name of the action to be executed. * @param array $args The arguments supplied to the functions hooked to `$tag`. */ function do_action_ref_array( $tag, $args ) { global $wp_filter, $wp_actions, $wp_current_filter; if ( ! isset( $wp_actions[ $tag ] ) ) { $wp_actions[ $tag ] = 1; } else { ++$wp_actions[ $tag ]; } // Do 'all' actions first if ( isset( $wp_filter['all'] ) ) { $wp_current_filter[] = $tag; $all_args = func_get_args(); _wp_call_all_hook( $all_args ); } if ( ! isset( $wp_filter[ $tag ] ) ) { if ( isset( $wp_filter['all'] ) ) { array_pop( $wp_current_filter ); } return; } if ( ! isset( $wp_filter['all'] ) ) { $wp_current_filter[] = $tag; } $wp_filter[ $tag ]->do_action( $args ); array_pop( $wp_current_filter ); } /** * Check if any action has been registered for a hook. * * @since 2.5.0 * * @see has_filter() has_action() is an alias of has_filter(). * * @param string $tag The name of the action hook. * @param callable|bool $function_to_check Optional. The callback to check for. Default false. * @return bool|int If $function_to_check is omitted, returns boolean for whether the hook has * anything registered. When checking a specific function, the priority of that * hook is returned, or false if the function is not attached. When using the * $function_to_check argument, this function may return a non-boolean value * that evaluates to false (e.g.) 0, so use the === operator for testing the * return value. */ function has_action( $tag, $function_to_check = false ) { return has_filter( $tag, $function_to_check ); } /** * 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. * * @since 1.2.0 * * @param string $tag The action hook to which the function to be removed is hooked. * @param callable $function_to_remove The name of the function which should be removed. * @param int $priority Optional. The priority of the function. Default 10. * @return bool Whether the function is removed. */ function remove_action( $tag, $function_to_remove, $priority = 10 ) { return remove_filter( $tag, $function_to_remove, $priority ); } /** * Remove all of the hooks from an action. * * @since 2.7.0 * * @param string $tag The action to remove hooks from. * @param int|bool $priority The priority number to remove them from. Default false. * @return true True when finished. */ function remove_all_actions( $tag, $priority = false ) { return remove_all_filters( $tag, $priority ); } /** * Fires functions attached to a deprecated filter hook. * * When a filter hook is deprecated, the apply_filters() call is replaced with * apply_filters_deprecated(), which triggers a deprecation notice and then fires * the original filter hook. * * Note: the value and extra arguments passed to the original apply_filters() call * must be passed here to `$args` as an array. For example: * * // Old filter. * return apply_filters( 'wpdocs_filter', $value, $extra_arg ); * * // Deprecated. * return apply_filters_deprecated( 'wpdocs_filter', array( $value, $extra_arg ), '4.9.0', 'wpdocs_new_filter' ); * * @since 4.6.0 * * @see _deprecated_hook() * * @param string $tag The name of the filter hook. * @param array $args Array of additional function arguments to be passed to apply_filters(). * @param string $version The version of WordPress that deprecated the hook. * @param string $replacement Optional. The hook that should have been used. Default false. * @param string $message Optional. A message regarding the change. Default null. */ function apply_filters_deprecated( $tag, $args, $version, $replacement = false, $message = null ) { if ( ! has_filter( $tag ) ) { return $args[0]; } _deprecated_hook( $tag, $version, $replacement, $message ); return apply_filters_ref_array( $tag, $args ); } /** * Fires functions attached to a deprecated action hook. * * When an action hook is deprecated, the do_action() call is replaced with * do_action_deprecated(), which triggers a deprecation notice and then fires * the original hook. * * @since 4.6.0 * * @see _deprecated_hook() * * @param string $tag The name of the action hook. * @param array $args Array of additional function arguments to be passed to do_action(). * @param string $version The version of WordPress that deprecated the hook. * @param string $replacement Optional. The hook that should have been used. * @param string $message Optional. A message regarding the change. */ function do_action_deprecated( $tag, $args, $version, $replacement = false, $message = null ) { if ( ! has_action( $tag ) ) { return; } _deprecated_hook( $tag, $version, $replacement, $message ); do_action_ref_array( $tag, $args ); } // // Functions for handling plugins. // /** * Gets the basename of a plugin. * * This method extracts the name of a plugin from its filename. * * @since 1.5.0 * * @global array $wp_plugin_paths * * @param string $file The filename of plugin. * @return string The name of a plugin. */ function plugin_basename( $file ) { global $wp_plugin_paths; // $wp_plugin_paths contains normalized paths. $file = wp_normalize_path( $file ); arsort( $wp_plugin_paths ); foreach ( $wp_plugin_paths as $dir => $realdir ) { if ( strpos( $file, $realdir ) === 0 ) { $file = $dir . substr( $file, strlen( $realdir ) ); } } $plugin_dir = wp_normalize_path( WP_PLUGIN_DIR ); $mu_plugin_dir = wp_normalize_path( WPMU_PLUGIN_DIR ); $file = preg_replace( '#^' . preg_quote( $plugin_dir, '#' ) . '/|^' . preg_quote( $mu_plugin_dir, '#' ) . '/#', '', $file ); // get relative path from plugins dir $file = trim( $file, '/' ); return $file; } /** * Register a plugin's real path. * * This is used in plugin_basename() to resolve symlinked paths. * * @since 3.9.0 * * @see wp_normalize_path() * * @global array $wp_plugin_paths * * @staticvar string $wp_plugin_path * @staticvar string $wpmu_plugin_path * * @param string $file Known path to the file. * @return bool Whether the path was able to be registered. */ function wp_register_plugin_realpath( $file ) { global $wp_plugin_paths; // Normalize, but store as static to avoid recalculation of a constant value static $wp_plugin_path = null, $wpmu_plugin_path = null; if ( ! isset( $wp_plugin_path ) ) { $wp_plugin_path = wp_normalize_path( WP_PLUGIN_DIR ); $wpmu_plugin_path = wp_normalize_path( WPMU_PLUGIN_DIR ); } $plugin_path = wp_normalize_path( dirname( $file ) ); $plugin_realpath = wp_normalize_path( dirname( realpath( $file ) ) ); if ( $plugin_path === $wp_plugin_path || $plugin_path === $wpmu_plugin_path ) { return false; } if ( $plugin_path !== $plugin_realpath ) { $wp_plugin_paths[ $plugin_path ] = $plugin_realpath; } return true; } /** * Get the filesystem directory path (with trailing slash) for the plugin __FILE__ passed in. * * @since 2.8.0 * * @param string $file The filename of the plugin (__FILE__). * @return string the filesystem path of the directory that contains the plugin. */ function plugin_dir_path( $file ) { return trailingslashit( dirname( $file ) ); } /** * Get the URL directory path (with trailing slash) for the plugin __FILE__ passed in. * * @since 2.8.0 * * @param string $file The filename of the plugin (__FILE__). * @return string the URL path of the directory that contains the plugin. */ function plugin_dir_url( $file ) { return trailingslashit( plugins_url( '', $file ) ); } /** * Set the activation hook for a plugin. * * When a plugin is activated, the action 'activate_PLUGINNAME' hook is * called. 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 wp-content/plugins/sampleplugin/sample.php, then * the 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 * wp-content/plugins/sample.php the name of this hook will be * 'activate_sample.php'. * * @since 2.0.0 * * @param string $file The filename of the plugin including the path. * @param callable $function The function hooked to the 'activate_PLUGIN' action. */ function register_activation_hook( $file, $function ) { $file = plugin_basename( $file ); add_action( 'activate_' . $file, $function ); } /** * Set the deactivation hook for a plugin. * * When a plugin is deactivated, the action 'deactivate_PLUGINNAME' hook is * called. 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 wp-content/plugins/sampleplugin/sample.php, then * the name of this hook will become 'deactivate_sampleplugin/sample.php'. * * When the plugin consists of only one file and is (as by default) located at * wp-content/plugins/sample.php the name of this hook will be * 'deactivate_sample.php'. * * @since 2.0.0 * * @param string $file The filename of the plugin including the path. * @param callable $function The function hooked to the 'deactivate_PLUGIN' action. */ function register_deactivation_hook( $file, $function ) { $file = plugin_basename( $file ); add_action( 'deactivate_' . $file, $function ); } /** * Set the uninstallation hook for a plugin. * * Registers the uninstall hook that will be called when the user clicks on the * uninstall link that calls for the plugin to uninstall itself. The link won't * be active unless the plugin hooks into the action. * * The plugin should not run arbitrary code outside of functions, when * registering the uninstall hook. In order to run using the hook, the plugin * will have to be included, which means that any code laying outside of a * function will be run during the uninstallation process. The plugin should not * hinder the uninstallation process. * * If the plugin can not be written without running code within the plugin, then * the plugin should create a file named 'uninstall.php' in the base plugin * folder. This file will be called, if it exists, during the uninstallation process * bypassing the uninstall hook. The plugin, when using the 'uninstall.php' * should always check for the 'WP_UNINSTALL_PLUGIN' constant, before * executing. * * @since 2.7.0 * * @param string $file Plugin file. * @param callable $callback The callback to run when the hook is called. Must be * a static method or function. */ function register_uninstall_hook( $file, $callback ) { if ( is_array( $callback ) && is_object( $callback[0] ) ) { _doing_it_wrong( __FUNCTION__, __( 'Only a static class method or function can be used in an uninstall hook.' ), '3.1.0' ); return; } /* * The option should not be autoloaded, because it is not needed in most * cases. Emphasis should be put on using the 'uninstall.php' way of * uninstalling the plugin. */ $uninstallable_plugins = (array) get_option( 'uninstall_plugins' ); $plugin_basename = plugin_basename( $file ); if ( ! isset( $uninstallable_plugins[ $plugin_basename ] ) || $uninstallable_plugins[ $plugin_basename ] !== $callback ) { $uninstallable_plugins[ $plugin_basename ] = $callback; update_option( 'uninstall_plugins', $uninstallable_plugins ); } } /** * Call 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. * * @since 2.5.0 * @access private * * @global array $wp_filter Stores all of the filters * * @param array $args The collected parameters from the hook that was called. */ function _wp_call_all_hook( $args ) { global $wp_filter; $wp_filter['all']->do_all_hook( $args ); } /** * 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 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. * * @link https://core.trac.wordpress.org/ticket/3875 * * @since 2.2.3 * @access private * * @global array $wp_filter Storage for all of the filters and actions. * @staticvar int $filter_id_count * * @param string $tag Used in counting how many hooks were applied * @param callable $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. * @return string|false Unique ID for usage as array key or false if $priority === false * and $function is an object reference, and it does not already have * a unique id. */ function _wp_filter_build_unique_id( $tag, $function, $priority ) { global $wp_filter; static $filter_id_count = 0; if ( is_string( $function ) ) { return $function; } if ( is_object( $function ) ) { // Closures are currently implemented as objects $function = array( $function, '' ); } else { $function = (array) $function; } if ( is_object( $function[0] ) ) { // Object Class Calling return spl_object_hash( $function[0] ) . $function[1]; } elseif ( is_string( $function[0] ) ) { // Static Calling return $function[0] . '::' . $function[1]; } }