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 return spl_object_hash( $function[0] ) . $function[1];
99 if ( is_string( $function[0] ) ) {
100 return $function[0]. '::' .$function[1];
106 * Performs a filtering operation on a YOURLS element or event.
110 * 1) Modify a variable if a function is attached to hook 'yourls_hook'
111 * $yourls_var = "default value";
112 * $yourls_var = yourls_apply_filter( 'yourls_hook', $yourls_var );
114 * 2) Trigger functions is attached to event 'yourls_event'
115 * yourls_apply_filter( 'yourls_event' );
116 * (see yourls_do_action() )
118 * Returns an element which may have been filtered by a filter.
120 * @global array $yourls_filters storage for all of the filters
121 * @param string $hook the name of the YOURLS element or action
122 * @param mixed $value the value of the element before filtering
125 function yourls_apply_filter( $hook, $value = '' ) {
126 global $yourls_filters;
127 if ( !isset( $yourls_filters[ $hook ] ) )
130 $args = func_get_args();
132 // Sort filters by priority
133 ksort( $yourls_filters[ $hook ] );
135 // Loops through each filter
136 reset( $yourls_filters[ $hook ] );
138 foreach( (array) current( $yourls_filters[ $hook ] ) as $the_ ) {
139 if ( !is_null( $the_['function'] ) ){
141 $count = $the_['accepted_args'];
142 if ( is_null( $count ) ) {
143 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1 ) );
145 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1, (int) $count ) );
148 if( $the_['type'] == 'filter' )
152 } while ( next( $yourls_filters[ $hook ] ) !== false );
154 if( $the_['type'] == 'filter' )
159 * Performs an action triggered by a YOURLS event.
161 * @param string $hook the name of the YOURLS action
162 * @param mixed $arg action arguments
164 function yourls_do_action( $hook, $arg = '' ) {
165 global $yourls_actions;
167 // Keep track of actions that are "done"
168 if ( !isset( $yourls_actions ) )
169 $yourls_actions = array();
170 if ( !isset( $yourls_actions[ $hook ] ) ) {
171 $yourls_actions[ $hook ] = 1;
173 ++$yourls_actions[ $hook ];
177 if ( is_array( $arg ) && 1 == count( $arg ) && isset( $arg[0] ) && is_object( $arg[0] ) ) // array(&$this)
181 for ( $a = 2; $a < func_num_args(); $a++ )
182 $args[] = func_get_arg( $a );
184 yourls_apply_filter( $hook, $args );
188 * Retrieve the number times an action is fired.
190 * @param string $hook Name of the action hook.
191 * @return int The number of times action hook <tt>$hook</tt> is fired
193 function yourls_did_action( $hook ) {
194 global $yourls_actions;
195 if ( !isset( $yourls_actions ) || !isset( $yourls_actions[ $hook ] ) )
197 return $yourls_actions[ $hook ];
201 * Removes a function from a specified filter hook.
203 * This function removes a function attached to a specified filter hook. This
204 * method can be used to remove default functions attached to a specific filter
205 * hook and possibly replace them with a substitute.
207 * To remove a hook, the $function_to_remove and $priority arguments must match
208 * when the hook was added.
210 * @global array $yourls_filters storage for all of the filters
211 * @param string $hook The filter hook to which the function to be removed is hooked.
212 * @param callback $function_to_remove The name of the function which should be removed.
213 * @param int $priority optional. The priority of the function (default: 10).
214 * @return boolean Whether the function was registered as a filter before it was removed.
216 function yourls_remove_filter( $hook, $function_to_remove, $priority = 10 ) {
217 global $yourls_filters;
219 $function_to_remove = yourls_filter_unique_id( $hook, $function_to_remove, $priority );
221 $remove = isset( $yourls_filters[ $hook ][ $priority ][ $function_to_remove ] );
223 if ( $remove === true ) {
224 unset ( $yourls_filters[$hook][$priority][$function_to_remove] );
225 if ( empty( $yourls_filters[$hook][$priority] ) )
226 unset( $yourls_filters[$hook] );
232 * Removes a function from a specified action hook.
234 * @see yourls_remove_filter()
236 * @param string $hook The action hook to which the function to be removed is hooked.
237 * @param callback $function_to_remove The name of the function which should be removed.
238 * @param int $priority optional. The priority of the function (default: 10).
239 * @return boolean Whether the function was registered as an action before it was removed.
242 function yourls_remove_action( $hook, $function_to_remove, $priority = 10 ) {
243 return yourls_remove_filter( $hook, $function_to_remove, $priority );
247 * Check if any filter has been registered for a hook.
249 * @global array $yourls_filters storage for all of the filters
250 * @param string $hook The name of the filter hook.
251 * @param callback $function_to_check optional. If specified, return the priority of that function on this hook or false if not attached.
252 * @return int|boolean Optionally returns the priority on that hook for the specified function.
254 function yourls_has_filter( $hook, $function_to_check = false ) {
255 global $yourls_filters;
257 $has = !empty( $yourls_filters[ $hook ] );
258 if ( false === $function_to_check || false == $has ) {
261 if ( !$idx = yourls_filter_unique_id( $hook, $function_to_check, false ) ) {
265 foreach ( (array) array_keys( $yourls_filters[ $hook ] ) as $priority ) {
266 if ( isset( $yourls_filters[ $hook ][ $priority ][ $idx ] ) )
272 function yourls_has_action( $hook, $function_to_check = false ) {
273 return yourls_has_filter( $hook, $function_to_check );
277 * Return number of active plugins
279 * @return integer Number of activated plugins
281 function yourls_has_active_plugins( ) {
284 if( !property_exists( $ydb, 'plugins' ) || !$ydb->plugins )
285 $ydb->plugins = array();
287 return count( $ydb->plugins );
292 * List plugins in /user/plugins
294 * @global object $ydb Storage of mostly everything YOURLS needs to know
295 * @return array Array of [/plugindir/plugin.php]=>array('Name'=>'Ozh', 'Title'=>'Hello', )
297 function yourls_get_plugins( ) {
298 $plugins = (array) glob( YOURLS_PLUGINDIR .'/*/plugin.php');
303 foreach( $plugins as $key => $plugin ) {
304 $_plugin = yourls_plugin_basename( $plugin );
305 $plugins[ $_plugin ] = yourls_get_plugin_data( $plugin );
306 unset( $plugins[ $key ] );
313 * Check if a plugin is active
315 * @param string $plugin Physical path to plugin file
318 function yourls_is_active_plugin( $plugin ) {
319 if( !yourls_has_active_plugins( ) )
323 $plugin = yourls_plugin_basename( $plugin );
325 return in_array( $plugin, $ydb->plugins );
330 * Parse a plugin header
332 * @param string $file Physical path to plugin file
333 * @return array Array of 'Field'=>'Value' from plugin comment header lines of the form "Field: Value"
335 function yourls_get_plugin_data( $file ) {
336 $fp = fopen( $file, 'r' ); // assuming $file is readable, since yourls_load_plugins() filters this
337 $data = fread( $fp, 8192 ); // get first 8kb
340 // Capture all the header within first comment block
341 if( !preg_match( '!.*?/\*(.*?)\*/!ms', $data, $matches ) )
344 // Capture each line with "Something: some text"
346 $lines = preg_split( "[\n|\r]", $matches[1] );
349 $plugin_data = array();
350 foreach( $lines as $line ) {
351 if( !preg_match( '!(.*?):\s+(.*)!', $line, $matches ) )
354 list( $null, $field, $value ) = array_map( 'trim', $matches);
355 $plugin_data[ $field ] = $value;
361 // Include active plugins
362 function yourls_load_plugins() {
363 // Don't load plugins when installing or updating
364 if( yourls_is_installing() OR yourls_is_upgrading() )
367 $active_plugins = yourls_get_option( 'active_plugins' );
368 if( false === $active_plugins )
372 $ydb->plugins = array();
374 foreach( (array)$active_plugins as $key=>$plugin ) {
375 if( yourls_validate_plugin_file( YOURLS_PLUGINDIR.'/'.$plugin ) ) {
376 include_once( YOURLS_PLUGINDIR.'/'.$plugin );
377 $ydb->plugins[] = $plugin;
378 unset( $active_plugins[$key] );
382 // $active_plugins should be empty now, if not, a plugin could not be find: remove it
383 if( count( $active_plugins ) ) {
384 yourls_update_option( 'active_plugins', $ydb->plugins );
385 $message = yourls_n( 'Could not find and deactivated plugin :', 'Could not find and deactivated plugins :', count( $active_plugins ) );
386 $missing = '<strong>'.join( '</strong>, <strong>', $active_plugins ).'</strong>';
387 yourls_add_notice( $message .' '. $missing );
392 * Check if a file is safe for inclusion (well, "safe", no guarantee)
394 * @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, $ydb->plugins ) )
428 return yourls__( 'Plugin already activated' );
430 // attempt activation. TODO: uber cool fail proof sandbox like in WP.
432 include_once( YOURLS_PLUGINDIR.'/'.$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 );
440 // so far, so good: update active plugin list
441 $ydb->plugins[] = $plugin;
442 yourls_update_option( 'active_plugins', $ydb->plugins );
443 yourls_do_action( 'activated_plugin', $plugin );
444 yourls_do_action( 'activated_' . $plugin );
450 * Deactivate a plugin
452 * @param string $plugin Plugin filename (full relative to plugins directory)
453 * @return mixed string if error or true if success
455 function yourls_deactivate_plugin( $plugin ) {
456 $plugin = yourls_plugin_basename( $plugin );
458 // Check plugin is active
459 if( !yourls_is_active_plugin( $plugin ) )
460 return yourls__( 'Plugin not active' );
462 // Deactivate the plugin
464 $key = array_search( $plugin, $ydb->plugins );
465 if( $key !== false ) {
466 array_splice( $ydb->plugins, $key, 1 );
469 yourls_update_option( 'active_plugins', $ydb->plugins );
470 yourls_do_action( 'deactivated_plugin', $plugin );
471 yourls_do_action( 'deactivated_' . $plugin );
477 * Return the path of a plugin file, relative to the plugins directory
479 function yourls_plugin_basename( $file ) {
480 $file = yourls_sanitize_filename( $file );
481 $plugindir = yourls_sanitize_filename( YOURLS_PLUGINDIR );
482 $file = str_replace( $plugindir, '', $file );
483 return trim( $file, '/' );
487 * Return the URL of the directory a plugin
489 function yourls_plugin_url( $file ) {
490 $url = YOURLS_PLUGINURL . '/' . yourls_plugin_basename( $file );
491 if( yourls_is_ssl() or yourls_needs_ssl() )
492 $url = str_replace( 'http://', 'https://', $url );
493 return yourls_apply_filter( 'plugin_url', $url, $file );
497 * Display list of links to plugin admin pages, if any
499 function yourls_list_plugin_admin_pages() {
502 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
505 $plugin_links = array();
506 foreach( (array)$ydb->plugin_pages as $plugin => $page ) {
507 $plugin_links[ $plugin ] = array(
508 'url' => yourls_admin_url( 'plugins.php?page='.$page['slug'] ),
509 'anchor' => $page['title'],
512 return $plugin_links;
516 * Register a plugin administration page
518 function yourls_register_plugin_page( $slug, $title, $function ) {
521 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
522 $ydb->plugin_pages = array();
524 $ydb->plugin_pages[ $slug ] = array(
527 'function' => $function,
532 * Handle plugin administration page
535 function yourls_plugin_admin_page( $plugin_page ) {
538 // Check the plugin page is actually registered
539 if( !isset( $ydb->plugin_pages[$plugin_page] ) ) {
540 yourls_die( yourls__( 'This page does not exist. Maybe a plugin you thought was activated is inactive?' ), yourls__( 'Invalid link' ) );
543 // Draw the page itself
544 yourls_do_action( 'load-' . $plugin_page);
545 yourls_html_head( 'plugin_page_' . $plugin_page, $ydb->plugin_pages[$plugin_page]['title'] );
549 call_user_func( $ydb->plugin_pages[$plugin_page]['function'] );
551 yourls_html_footer();
558 * Callback function: Sort plugins
560 * @link http://php.net/uasort
562 * @param array $plugin_a
563 * @param array $plugin_b
564 * @return int 0, 1 or -1, see uasort()
566 function yourls_plugins_sort_callback( $plugin_a, $plugin_b ) {
567 $orderby = yourls_apply_filter( 'plugins_sort_callback', 'Plugin Name' );
568 $order = yourls_apply_filter( 'plugins_sort_callback', 'ASC' );
570 $a = isset( $plugin_a[ $orderby ] ) ? $plugin_a[ $orderby ] : '';
571 $b = isset( $plugin_b[ $orderby ] ) ? $plugin_b[ $orderby ] : '';
576 if ( 'DESC' == $order )
577 return ( $a < $b ) ? 1 : -1;
579 return ( $a < $b ) ? -1 : 1;