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).
35 function yourls_add_filter( $hook, $function_name, $priority = 10, $accepted_args = NULL, $type = 'filter' ) {
36 global $yourls_filters;
37 // At this point, we cannot check if the function exists, as it may well be defined later (which is OK)
38 $id = yourls_filter_unique_id( $hook, $function_name, $priority );
40 $yourls_filters[ $hook ][ $priority ][ $id ] = array(
41 'function' => $function_name,
42 'accepted_args' => $accepted_args,
48 * Hooks a function on to a specific action.
50 * Actions are the hooks that YOURLS launches at specific points
51 * during execution, or when specific events occur. Plugins can specify that
52 * one or more of its PHP functions are executed at these points, using the
55 * @param string $hook The name of the action to which the $function_to_add is hooked.
56 * @param callback $function_name The name of the function you wish to be called.
57 * @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.
58 * @param int $accepted_args optional. The number of arguments the function accept (default 1).
60 function yourls_add_action( $hook, $function_name, $priority = 10, $accepted_args = 1 ) {
61 return yourls_add_filter( $hook, $function_name, $priority, $accepted_args, 'action' );
67 * Build Unique ID for storage and retrieval.
69 * Simply using a function name is not enough, as several functions can have the same name when they are enclosed in classes.
71 * @global array $yourls_filters storage for all of the filters
72 * @param string $hook hook to which the function is attached
73 * @param string|array $function used for creating unique id
74 * @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.
75 * @param string $type filter or action
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 ) )
84 // Object Class Calling
85 else if ( is_object( $function[0] ) ) {
86 $obj_idx = get_class( $function[0] ) . $function[1];
87 if ( !isset( $function[0]->_yourls_filters_id ) ) {
88 if ( false === $priority )
90 $count = isset( $yourls_filters[ $hook ][ $priority ]) ? count( (array)$yourls_filters[ $hook ][ $priority ] ) : 0;
91 $function[0]->_yourls_filters_id = $count;
95 $obj_idx .= $function[0]->_yourls_filters_id;
99 else if ( is_string( $function[0] ) )
100 return $function[0].$function[1];
105 * Performs a filtering operation on a YOURLS element or event.
109 * 1) Modify a variable if a function is attached to hook 'yourls_hook'
110 * $yourls_var = "default value";
111 * $yourls_var = yourls_apply_filter( 'yourls_hook', $yourls_var );
113 * 2) Trigger functions is attached to event 'yourls_event'
114 * yourls_apply_filter( 'yourls_event' );
115 * (see yourls_do_action() )
117 * Returns an element which may have been filtered by a filter.
119 * @global array $yourls_filters storage for all of the filters
120 * @param string $hook the name of the YOURLS element or action
121 * @param mixed $value the value of the element before filtering
124 function yourls_apply_filter( $hook, $value = '' ) {
125 global $yourls_filters;
126 if ( !isset( $yourls_filters[ $hook ] ) )
129 $args = func_get_args();
131 // Sort filters by priority
132 ksort( $yourls_filters[ $hook ] );
134 // Loops through each filter
135 reset( $yourls_filters[ $hook ] );
137 foreach( (array) current( $yourls_filters[ $hook ] ) as $the_ ) {
138 if ( !is_null( $the_['function'] ) ){
140 $count = $the_['accepted_args'];
141 if ( is_null( $count ) ) {
142 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1 ) );
144 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1, (int) $count ) );
147 if( $the_['type'] == 'filter' )
151 } while ( next( $yourls_filters[ $hook ] ) !== false );
153 if( $the_['type'] == 'filter' )
158 * Alias for yourls_apply_filter because I never remember if it's _filter or _filters
160 * Plus, semantically, it makes more sense. There can be several filters. I should have named it
161 * like this from the very start. Duh.
165 * @param string $hook the name of the YOURLS element or action
166 * @param mixed $value the value of the element before filtering
169 function yourls_apply_filters( $hook, $value = '' ) {
170 return yourls_apply_filter( $hook, $value );
175 * Performs an action triggered by a YOURLS event.
177 * @param string $hook the name of the YOURLS action
178 * @param mixed $arg action arguments
180 function yourls_do_action( $hook, $arg = '' ) {
181 global $yourls_actions;
183 // Keep track of actions that are "done"
184 if ( !isset( $yourls_actions ) )
185 $yourls_actions = array();
186 if ( !isset( $yourls_actions[ $hook ] ) )
187 $yourls_actions[ $hook ] = 1;
189 ++$yourls_actions[ $hook ];
192 if ( is_array( $arg ) && 1 == count( $arg ) && isset( $arg[0] ) && is_object( $arg[0] ) ) // array(&$this)
196 for ( $a = 2; $a < func_num_args(); $a++ )
197 $args[] = func_get_arg( $a );
199 yourls_apply_filter( $hook, $args );
203 * Retrieve the number times an action is fired.
205 * @param string $hook Name of the action hook.
206 * @return int The number of times action hook <tt>$hook</tt> is fired
208 function yourls_did_action( $hook ) {
209 global $yourls_actions;
210 if ( !isset( $yourls_actions ) || !isset( $yourls_actions[ $hook ] ) )
212 return $yourls_actions[ $hook ];
216 * Removes a function from a specified filter hook.
218 * This function removes a function attached to a specified filter hook. This
219 * method can be used to remove default functions attached to a specific filter
220 * hook and possibly replace them with a substitute.
222 * To remove a hook, the $function_to_remove and $priority arguments must match
223 * when the hook was added.
225 * @global array $yourls_filters storage for all of the filters
226 * @param string $hook The filter hook to which the function to be removed is hooked.
227 * @param callback $function_to_remove The name of the function which should be removed.
228 * @param int $priority optional. The priority of the function (default: 10).
229 * @param int $accepted_args optional. The number of arguments the function accepts (default: 1).
230 * @return boolean Whether the function was registered as a filter before it was removed.
232 function yourls_remove_filter( $hook, $function_to_remove, $priority = 10, $accepted_args = 1 ) {
233 global $yourls_filters;
235 $function_to_remove = yourls_filter_unique_id( $hook, $function_to_remove, $priority );
237 $remove = isset( $yourls_filters[ $hook ][ $priority ][ $function_to_remove ] );
239 if ( $remove === true ) {
240 unset ( $yourls_filters[$hook][$priority][$function_to_remove] );
241 if ( empty( $yourls_filters[$hook][$priority] ) )
242 unset( $yourls_filters[$hook] );
249 * Check if any filter has been registered for a hook.
251 * @global array $yourls_filters storage for all of the filters
252 * @param string $hook The name of the filter hook.
253 * @param callback $function_to_check optional. If specified, return the priority of that function on this hook or false if not attached.
254 * @return int|boolean Optionally returns the priority on that hook for the specified function.
256 function yourls_has_filter( $hook, $function_to_check = false ) {
257 global $yourls_filters;
259 $has = !empty( $yourls_filters[ $hook ] );
260 if ( false === $function_to_check || false == $has ) {
263 if ( !$idx = yourls_filter_unique_id( $hook, $function_to_check, false ) ) {
267 foreach ( (array) array_keys( $yourls_filters[ $hook ] ) as $priority ) {
268 if ( isset( $yourls_filters[ $hook ][ $priority ][ $idx ] ) )
274 function yourls_has_action( $hook, $function_to_check = false ) {
275 return yourls_has_filter( $hook, $function_to_check );
279 * Return number of active plugins
281 * @return integer Number of activated plugins
283 function yourls_has_active_plugins( ) {
286 if( !property_exists( $ydb, 'plugins' ) || !$ydb->plugins )
287 $ydb->plugins = array();
289 return count( $ydb->plugins );
294 * List plugins in /user/plugins
296 * @global $ydb Storage of mostly everything YOURLS needs to know
297 * @return array Array of [/plugindir/plugin.php]=>array('Name'=>'Ozh', 'Title'=>'Hello', )
299 function yourls_get_plugins( ) {
302 $plugins = (array) glob( YOURLS_PLUGINDIR .'/*/plugin.php');
307 foreach( $plugins as $key => $plugin ) {
308 $_plugin = yourls_plugin_basename( $plugin );
309 $plugins[ $_plugin ] = yourls_get_plugin_data( $plugin );
310 unset( $plugins[ $key ] );
317 * Check if a plugin is active
319 * @param string $file Physical path to plugin file
322 function yourls_is_active_plugin( $plugin ) {
323 if( !yourls_has_active_plugins( ) )
327 $plugin = yourls_plugin_basename( $plugin );
329 return in_array( $plugin, $ydb->plugins );
334 * Parse a plugin header
336 * @param string $file Physical path to plugin file
337 * @return array Array of 'Field'=>'Value' from plugin comment header lines of the form "Field: Value"
339 function yourls_get_plugin_data( $file ) {
340 $fp = fopen( $file, 'r' ); // assuming $file is readable, since yourls_load_plugins() filters this
341 $data = fread( $fp, 8192 ); // get first 8kb
344 // Capture all the header within first comment block
345 if( !preg_match( '!.*?/\*(.*?)\*/!ms', $data, $matches ) )
348 // Capture each line with "Something: some text"
350 $lines = preg_split( "[\n|\r]", $matches[1] );
353 $plugin_data = array();
354 foreach( $lines as $line ) {
355 if( !preg_match( '!(.*?):\s+(.*)!', $line, $matches ) )
358 list( $null, $field, $value ) = array_map( 'trim', $matches);
359 $plugin_data[ $field ] = $value;
365 // Include active plugins
366 function yourls_load_plugins() {
368 $ydb->plugins = array();
369 $active_plugins = yourls_get_option( 'active_plugins' );
371 // Don't load plugins when installing or updating
372 if( !$active_plugins OR yourls_is_installing() OR yourls_upgrade_is_needed() )
375 foreach( (array)$active_plugins as $key=>$plugin ) {
376 if( yourls_validate_plugin_file( YOURLS_PLUGINDIR.'/'.$plugin ) ) {
377 include_once( YOURLS_PLUGINDIR.'/'.$plugin );
378 $ydb->plugins[] = $plugin;
379 unset( $active_plugins[$key] );
383 // $active_plugins should be empty now, if not, a plugin could not be find: remove it
384 if( count( $active_plugins ) ) {
385 yourls_update_option( 'active_plugins', $ydb->plugins );
386 $message = yourls_n( 'Could not find and deactivated plugin :', 'Could not find and deactivated plugins :', count( $active_plugins ) );
387 $missing = '<strong>'.join( '</strong>, <strong>', $active_plugins ).'</strong>';
388 yourls_add_notice( $message .' '. $missing );
393 * Check if a file is safe for inclusion (well, "safe", no guarantee)
395 * @param string $file Full pathname to a file
397 function yourls_validate_plugin_file( $file ) {
399 false !== strpos( $file, '..' )
401 false !== strpos( $file, './' )
403 'plugin.php' !== substr( $file, -10 ) // a plugin must be named 'plugin.php'
405 !is_readable( $file )
415 * @param string $plugin Plugin filename (full or relative to plugins directory)
416 * @return mixed string if error or true if success
418 function yourls_activate_plugin( $plugin ) {
420 $plugin = yourls_plugin_basename( $plugin );
421 $plugindir = yourls_sanitize_filename( YOURLS_PLUGINDIR );
422 if( !yourls_validate_plugin_file( $plugindir.'/'.$plugin ) )
423 return yourls__( 'Not a valid plugin file' );
425 // check not activated already
427 if( yourls_has_active_plugins() && in_array( $plugin, $ydb->plugins ) )
428 return yourls__( 'Plugin already activated' );
430 // attempt activation. TODO: uber cool fail proof sandbox like in WP.
432 include( YOURLS_PLUGINDIR.'/'.$plugin );
433 if ( ob_get_length() > 0 ) {
434 // there was some output: error
435 $output = ob_get_clean();
436 return yourls_s( 'Plugin generated unexpected output. Error was: <br/><pre>%s</pre>', $output );
439 // so far, so good: update active plugin list
440 $ydb->plugins[] = $plugin;
441 yourls_update_option( 'active_plugins', $ydb->plugins );
442 yourls_do_action( 'activated_plugin', $plugin );
443 yourls_do_action( 'activated_' . $plugin );
451 * @param string $plugin Plugin filename (full relative to plugins directory)
452 * @return mixed string if error or true if success
454 function yourls_deactivate_plugin( $plugin ) {
455 $plugin = yourls_plugin_basename( $plugin );
457 // Check plugin is active
458 if( !yourls_is_active_plugin( $plugin ) )
459 return yourls__( 'Plugin not active' );
461 // Deactivate the plugin
463 $key = array_search( $plugin, $ydb->plugins );
464 if( $key !== false ) {
465 array_splice( $ydb->plugins, $key, 1 );
468 yourls_update_option( 'active_plugins', $ydb->plugins );
469 yourls_do_action( 'deactivated_plugin', $plugin );
470 yourls_do_action( 'deactivated_' . $plugin );
476 * Return the path of a plugin file, relative to the plugins directory
478 function yourls_plugin_basename( $file ) {
479 $file = yourls_sanitize_filename( $file );
480 $plugindir = yourls_sanitize_filename( YOURLS_PLUGINDIR );
481 $file = str_replace( $plugindir, '', $file );
482 return trim( $file, '/' );
486 * Return the URL of the directory a plugin
488 function yourls_plugin_url( $file ) {
489 $url = YOURLS_PLUGINURL . '/' . yourls_plugin_basename( $file );
490 if( yourls_is_ssl() or yourls_needs_ssl() )
491 $url = str_replace( 'http://', 'https://', $url );
492 return yourls_apply_filter( 'plugin_url', $url, $file );
496 * Display list of links to plugin admin pages, if any
498 function yourls_list_plugin_admin_pages() {
501 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
504 $plugin_links = array();
505 foreach( (array)$ydb->plugin_pages as $plugin => $page ) {
506 $plugin_links[ $plugin ] = array(
507 'url' => yourls_admin_url( 'plugins.php?page='.$page['slug'] ),
508 'anchor' => $page['title'],
511 return $plugin_links;
515 * Register a plugin administration page
517 function yourls_register_plugin_page( $slug, $title, $function ) {
520 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
521 $ydb->plugin_pages = array();
523 $ydb->plugin_pages[ $slug ] = array(
526 'function' => $function,
531 * Handle plugin administration page
534 function yourls_plugin_admin_page( $plugin_page ) {
537 // Check the plugin page is actually registered
538 if( !isset( $ydb->plugin_pages[$plugin_page] ) ) {
539 yourls_die( yourls__( 'This page does not exist. Maybe a plugin you thought was activated is inactive?' ), yourls__( 'Invalid link' ) );
542 // Draw the page itself
543 yourls_do_action( 'load-' . $plugin_page);
544 yourls_html_head( 'plugin_page_' . $plugin_page, $ydb->plugin_pages[$plugin_page]['title'] );
548 call_user_func( $ydb->plugin_pages[$plugin_page]['function'] );
550 yourls_html_footer();
557 * Callback function: Sort plugins
559 * @link http://php.net/uasort
561 * @param array $plugin_a
562 * @param array $plugin_b
563 * @return int 0, 1 or -1, see uasort()
565 function yourls_plugins_sort_callback( $plugin_a, $plugin_b ) {
566 $orderby = yourls_apply_filters( 'plugins_sort_callback', 'Plugin Name' );
567 $order = yourls_apply_filters( 'plugins_sort_callback', 'ASC' );
569 $a = $plugin_a[$orderby];
570 $b = $plugin_b[$orderby];
575 if ( 'DESC' == $order )
576 return ( $a < $b ) ? 1 : -1;
578 return ( $a < $b ) ? -1 : 1;