4 * The filter/plugin API is located in this file, which allows for creating filters
5 * and hooking functions, and methods. The functions or methods will be run when
6 * the filter is called.
8 * Any of the syntaxes explained in the PHP documentation for the
9 * {@link http://us2.php.net/manual/en/language.pseudo-types.php#language.types.callback 'callback'}
12 * This API is heavily inspired by the one I implemented in Zenphoto 1.3, which was heavily inspired by the one used in WordPress.
18 $yourls_filters = array();
19 /* This global var will collect filters with the following structure:
20 * $yourls_filters['hook']['array of priorities']['serialized function names']['array of ['array (functions, accepted_args)]']
24 * Registers a filtering function
27 * yourls_add_filter('some_hook', 'function_handler_for_hook');
29 * @global array $yourls_filters Storage for all of the filters
30 * @param string $hook the name of the YOURLS element to be filtered or YOURLS action to be triggered
31 * @param callback $function_name the name of the function that is to be called.
32 * @param integer $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default=10, lower=earlier execution, and functions with the same priority are executed in the order in which they were added to the filter)
33 * @param int $accepted_args optional. The number of arguments the function accept (default is the number provided).
36 function yourls_add_filter( $hook, $function_name, $priority = 10, $accepted_args = NULL, $type = 'filter' ) {
37 global $yourls_filters;
38 // At this point, we cannot check if the function exists, as it may well be defined later (which is OK)
39 $id = yourls_filter_unique_id( $hook, $function_name, $priority );
41 $yourls_filters[ $hook ][ $priority ][ $id ] = array(
42 'function' => $function_name,
43 'accepted_args' => $accepted_args,
49 * Hooks a function on to a specific action.
51 * Actions are the hooks that YOURLS launches at specific points
52 * during execution, or when specific events occur. Plugins can specify that
53 * one or more of its PHP functions are executed at these points, using the
56 * @param string $hook The name of the action to which the $function_to_add is hooked.
57 * @param callback $function_name The name of the function you wish to be called.
58 * @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.
59 * @param int $accepted_args optional. The number of arguments the function accept (default 1).
61 function yourls_add_action( $hook, $function_name, $priority = 10, $accepted_args = 1 ) {
62 return yourls_add_filter( $hook, $function_name, $priority, $accepted_args, 'action' );
68 * Build Unique ID for storage and retrieval.
70 * Simply using a function name is not enough, as several functions can have the same name when they are enclosed in classes.
72 * @global array $yourls_filters storage for all of the filters
73 * @param string $hook hook to which the function is attached
74 * @param string|array $function used for creating unique id
75 * @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.
76 * @return string unique ID for usage as array key
78 function yourls_filter_unique_id( $hook, $function, $priority ) {
79 global $yourls_filters;
81 // If function then just skip all of the tests and not overwrite the following.
82 if ( is_string( $function ) ) {
86 if( is_object($function) ) {
87 // Closures are currently implemented as objects
88 $function = array( $function, '' );
90 $function = (array) $function;
93 // Object Class Calling
94 if ( is_object( $function[0] ) ) {
95 // Object Class Calling
96 if ( function_exists('spl_object_hash') ) {
97 return spl_object_hash($function[0]) . $function[1];
99 $obj_idx = get_class( $function[0] ) . $function[1];
100 if ( !isset( $function[0]->_yourls_filters_id ) ) {
101 if ( false === $priority )
103 $count = isset( $yourls_filters[ $hook ][ $priority ]) ? count( (array)$yourls_filters[ $hook ][ $priority ] ) : 0;
104 $function[0]->_yourls_filters_id = $count;
108 $obj_idx .= $function[0]->_yourls_filters_id;
115 else if ( is_string( $function[0] ) ) {
116 return $function[0]. '::' .$function[1];
121 * Performs a filtering operation on a YOURLS element or event.
125 * 1) Modify a variable if a function is attached to hook 'yourls_hook'
126 * $yourls_var = "default value";
127 * $yourls_var = yourls_apply_filter( 'yourls_hook', $yourls_var );
129 * 2) Trigger functions is attached to event 'yourls_event'
130 * yourls_apply_filter( 'yourls_event' );
131 * (see yourls_do_action() )
133 * Returns an element which may have been filtered by a filter.
135 * @global array $yourls_filters storage for all of the filters
136 * @param string $hook the name of the YOURLS element or action
137 * @param mixed $value the value of the element before filtering
140 function yourls_apply_filter( $hook, $value = '' ) {
141 global $yourls_filters;
142 if ( !isset( $yourls_filters[ $hook ] ) )
145 $args = func_get_args();
147 // Sort filters by priority
148 ksort( $yourls_filters[ $hook ] );
150 // Loops through each filter
151 reset( $yourls_filters[ $hook ] );
153 foreach( (array) current( $yourls_filters[ $hook ] ) as $the_ ) {
154 if ( !is_null( $the_['function'] ) ){
156 $count = $the_['accepted_args'];
157 if ( is_null( $count ) ) {
158 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1 ) );
160 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1, (int) $count ) );
163 if( $the_['type'] == 'filter' )
167 } while ( next( $yourls_filters[ $hook ] ) !== false );
169 if( $the_['type'] == 'filter' )
174 * Performs an action triggered by a YOURLS event.
176 * @param string $hook the name of the YOURLS action
177 * @param mixed $arg action arguments
179 function yourls_do_action( $hook, $arg = '' ) {
180 global $yourls_actions;
182 // Keep track of actions that are "done"
183 if ( !isset( $yourls_actions ) )
184 $yourls_actions = array();
185 if ( !isset( $yourls_actions[ $hook ] ) )
186 $yourls_actions[ $hook ] = 1;
188 ++$yourls_actions[ $hook ];
191 if ( is_array( $arg ) && 1 == count( $arg ) && isset( $arg[0] ) && is_object( $arg[0] ) ) // array(&$this)
195 for ( $a = 2; $a < func_num_args(); $a++ )
196 $args[] = func_get_arg( $a );
198 yourls_apply_filter( $hook, $args );
202 * Retrieve the number times an action is fired.
204 * @param string $hook Name of the action hook.
205 * @return int The number of times action hook <tt>$hook</tt> is fired
207 function yourls_did_action( $hook ) {
208 global $yourls_actions;
209 if ( !isset( $yourls_actions ) || !isset( $yourls_actions[ $hook ] ) )
211 return $yourls_actions[ $hook ];
215 * Removes a function from a specified filter hook.
217 * This function removes a function attached to a specified filter hook. This
218 * method can be used to remove default functions attached to a specific filter
219 * hook and possibly replace them with a substitute.
221 * To remove a hook, the $function_to_remove and $priority arguments must match
222 * when the hook was added.
224 * @global array $yourls_filters storage for all of the filters
225 * @param string $hook The filter hook to which the function to be removed is hooked.
226 * @param callback $function_to_remove The name of the function which should be removed.
227 * @param int $priority optional. The priority of the function (default: 10).
228 * @return boolean Whether the function was registered as a filter before it was removed.
230 function yourls_remove_filter( $hook, $function_to_remove, $priority = 10 ) {
231 global $yourls_filters;
233 $function_to_remove = yourls_filter_unique_id( $hook, $function_to_remove, $priority );
235 $remove = isset( $yourls_filters[ $hook ][ $priority ][ $function_to_remove ] );
237 if ( $remove === true ) {
238 unset ( $yourls_filters[$hook][$priority][$function_to_remove] );
239 if ( empty( $yourls_filters[$hook][$priority] ) )
240 unset( $yourls_filters[$hook] );
246 * Removes a function from a specified action hook.
248 * @see yourls_remove_filter()
250 * @param string $hook The action hook to which the function to be removed is hooked.
251 * @param callback $function_to_remove The name of the function which should be removed.
252 * @param int $priority optional. The priority of the function (default: 10).
253 * @return boolean Whether the function was registered as an action before it was removed.
256 function yourls_remove_action( $hook, $function_to_remove, $priority = 10 ) {
257 return yourls_remove_filter( $hook, $function_to_remove, $priority );
261 * Check if any filter has been registered for a hook.
263 * @global array $yourls_filters storage for all of the filters
264 * @param string $hook The name of the filter hook.
265 * @param callback $function_to_check optional. If specified, return the priority of that function on this hook or false if not attached.
266 * @return int|boolean Optionally returns the priority on that hook for the specified function.
268 function yourls_has_filter( $hook, $function_to_check = false ) {
269 global $yourls_filters;
271 $has = !empty( $yourls_filters[ $hook ] );
272 if ( false === $function_to_check || false == $has ) {
275 if ( !$idx = yourls_filter_unique_id( $hook, $function_to_check, false ) ) {
279 foreach ( (array) array_keys( $yourls_filters[ $hook ] ) as $priority ) {
280 if ( isset( $yourls_filters[ $hook ][ $priority ][ $idx ] ) )
286 function yourls_has_action( $hook, $function_to_check = false ) {
287 return yourls_has_filter( $hook, $function_to_check );
291 * Return number of active plugins
293 * @return integer Number of activated plugins
295 function yourls_has_active_plugins( ) {
298 if( !property_exists( $ydb, 'plugins' ) || !$ydb->plugins )
299 $ydb->plugins = array();
301 return count( $ydb->plugins );
306 * List plugins in /user/plugins
308 * @global object $ydb Storage of mostly everything YOURLS needs to know
309 * @return array Array of [/plugindir/plugin.php]=>array('Name'=>'Ozh', 'Title'=>'Hello', )
311 function yourls_get_plugins( ) {
312 $plugins = (array) glob( YOURLS_PLUGINDIR .'/*/plugin.php');
317 foreach( $plugins as $key => $plugin ) {
318 $_plugin = yourls_plugin_basename( $plugin );
319 $plugins[ $_plugin ] = yourls_get_plugin_data( $plugin );
320 unset( $plugins[ $key ] );
327 * Check if a plugin is active
329 * @param string $plugin Physical path to plugin file
332 function yourls_is_active_plugin( $plugin ) {
333 if( !yourls_has_active_plugins( ) )
337 $plugin = yourls_plugin_basename( $plugin );
339 return in_array( $plugin, $ydb->plugins );
344 * Parse a plugin header
346 * @param string $file Physical path to plugin file
347 * @return array Array of 'Field'=>'Value' from plugin comment header lines of the form "Field: Value"
349 function yourls_get_plugin_data( $file ) {
350 $fp = fopen( $file, 'r' ); // assuming $file is readable, since yourls_load_plugins() filters this
351 $data = fread( $fp, 8192 ); // get first 8kb
354 // Capture all the header within first comment block
355 if( !preg_match( '!.*?/\*(.*?)\*/!ms', $data, $matches ) )
358 // Capture each line with "Something: some text"
360 $lines = preg_split( "[\n|\r]", $matches[1] );
363 $plugin_data = array();
364 foreach( $lines as $line ) {
365 if( !preg_match( '!(.*?):\s+(.*)!', $line, $matches ) )
368 list( $null, $field, $value ) = array_map( 'trim', $matches);
369 $plugin_data[ $field ] = $value;
375 // Include active plugins
376 function yourls_load_plugins() {
377 // Don't load plugins when installing or updating
378 if( yourls_is_installing() OR yourls_is_upgrading() )
381 $active_plugins = yourls_get_option( 'active_plugins' );
382 if( false === $active_plugins )
386 $ydb->plugins = array();
388 foreach( (array)$active_plugins as $key=>$plugin ) {
389 if( yourls_validate_plugin_file( YOURLS_PLUGINDIR.'/'.$plugin ) ) {
390 include_once( YOURLS_PLUGINDIR.'/'.$plugin );
391 $ydb->plugins[] = $plugin;
392 unset( $active_plugins[$key] );
396 // $active_plugins should be empty now, if not, a plugin could not be find: remove it
397 if( count( $active_plugins ) ) {
398 yourls_update_option( 'active_plugins', $ydb->plugins );
399 $message = yourls_n( 'Could not find and deactivated plugin :', 'Could not find and deactivated plugins :', count( $active_plugins ) );
400 $missing = '<strong>'.join( '</strong>, <strong>', $active_plugins ).'</strong>';
401 yourls_add_notice( $message .' '. $missing );
406 * Check if a file is safe for inclusion (well, "safe", no guarantee)
408 * @param string $file Full pathname to a file
411 function yourls_validate_plugin_file( $file ) {
413 false !== strpos( $file, '..' )
415 false !== strpos( $file, './' )
417 'plugin.php' !== substr( $file, -10 ) // a plugin must be named 'plugin.php'
419 !is_readable( $file )
429 * @param string $plugin Plugin filename (full or relative to plugins directory)
430 * @return mixed string if error or true if success
432 function yourls_activate_plugin( $plugin ) {
434 $plugin = yourls_plugin_basename( $plugin );
435 $plugindir = yourls_sanitize_filename( YOURLS_PLUGINDIR );
436 if( !yourls_validate_plugin_file( $plugindir.'/'.$plugin ) )
437 return yourls__( 'Not a valid plugin file' );
439 // check not activated already
441 if( yourls_has_active_plugins() && in_array( $plugin, $ydb->plugins ) )
442 return yourls__( 'Plugin already activated' );
444 // attempt activation. TODO: uber cool fail proof sandbox like in WP.
446 include_once( YOURLS_PLUGINDIR.'/'.$plugin );
447 if ( ob_get_length() > 0 ) {
448 // there was some output: error
449 $output = ob_get_clean();
450 return yourls_s( 'Plugin generated unexpected output. Error was: <br/><pre>%s</pre>', $output );
454 // so far, so good: update active plugin list
455 $ydb->plugins[] = $plugin;
456 yourls_update_option( 'active_plugins', $ydb->plugins );
457 yourls_do_action( 'activated_plugin', $plugin );
458 yourls_do_action( 'activated_' . $plugin );
464 * Deactivate a plugin
466 * @param string $plugin Plugin filename (full relative to plugins directory)
467 * @return mixed string if error or true if success
469 function yourls_deactivate_plugin( $plugin ) {
470 $plugin = yourls_plugin_basename( $plugin );
472 // Check plugin is active
473 if( !yourls_is_active_plugin( $plugin ) )
474 return yourls__( 'Plugin not active' );
476 // Deactivate the plugin
478 $key = array_search( $plugin, $ydb->plugins );
479 if( $key !== false ) {
480 array_splice( $ydb->plugins, $key, 1 );
483 yourls_update_option( 'active_plugins', $ydb->plugins );
484 yourls_do_action( 'deactivated_plugin', $plugin );
485 yourls_do_action( 'deactivated_' . $plugin );
491 * Return the path of a plugin file, relative to the plugins directory
493 function yourls_plugin_basename( $file ) {
494 $file = yourls_sanitize_filename( $file );
495 $plugindir = yourls_sanitize_filename( YOURLS_PLUGINDIR );
496 $file = str_replace( $plugindir, '', $file );
497 return trim( $file, '/' );
501 * Return the URL of the directory a plugin
503 function yourls_plugin_url( $file ) {
504 $url = YOURLS_PLUGINURL . '/' . yourls_plugin_basename( $file );
505 if( yourls_is_ssl() or yourls_needs_ssl() )
506 $url = str_replace( 'http://', 'https://', $url );
507 return yourls_apply_filter( 'plugin_url', $url, $file );
511 * Display list of links to plugin admin pages, if any
513 function yourls_list_plugin_admin_pages() {
516 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
519 $plugin_links = array();
520 foreach( (array)$ydb->plugin_pages as $plugin => $page ) {
521 $plugin_links[ $plugin ] = array(
522 'url' => yourls_admin_url( 'plugins.php?page='.$page['slug'] ),
523 'anchor' => $page['title'],
526 return $plugin_links;
530 * Register a plugin administration page
532 function yourls_register_plugin_page( $slug, $title, $function ) {
535 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
536 $ydb->plugin_pages = array();
538 $ydb->plugin_pages[ $slug ] = array(
541 'function' => $function,
546 * Handle plugin administration page
549 function yourls_plugin_admin_page( $plugin_page ) {
552 // Check the plugin page is actually registered
553 if( !isset( $ydb->plugin_pages[$plugin_page] ) ) {
554 yourls_die( yourls__( 'This page does not exist. Maybe a plugin you thought was activated is inactive?' ), yourls__( 'Invalid link' ) );
557 // Draw the page itself
558 yourls_do_action( 'load-' . $plugin_page);
559 yourls_html_head( 'plugin_page_' . $plugin_page, $ydb->plugin_pages[$plugin_page]['title'] );
563 call_user_func( $ydb->plugin_pages[$plugin_page]['function'] );
565 yourls_html_footer();
572 * Callback function: Sort plugins
574 * @link http://php.net/uasort
576 * @param array $plugin_a
577 * @param array $plugin_b
578 * @return int 0, 1 or -1, see uasort()
580 function yourls_plugins_sort_callback( $plugin_a, $plugin_b ) {
581 $orderby = yourls_apply_filter( 'plugins_sort_callback', 'Plugin Name' );
582 $order = yourls_apply_filter( 'plugins_sort_callback', 'ASC' );
584 $a = isset( $plugin_a[ $orderby ] ) ? $plugin_a[ $orderby ] : '';
585 $b = isset( $plugin_b[ $orderby ] ) ? $plugin_b[ $orderby ] : '';
590 if ( 'DESC' == $order )
591 return ( $a < $b ) ? 1 : -1;
593 return ( $a < $b ) ? -1 : 1;