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];
98 else if ( is_string( $function[0] ) ) {
99 return $function[0]. '::' .$function[1];
104 * Performs a filtering operation on a YOURLS element or event.
108 * 1) Modify a variable if a function is attached to hook 'yourls_hook'
109 * $yourls_var = "default value";
110 * $yourls_var = yourls_apply_filter( 'yourls_hook', $yourls_var );
112 * 2) Trigger functions is attached to event 'yourls_event'
113 * yourls_apply_filter( 'yourls_event' );
114 * (see yourls_do_action() )
116 * Returns an element which may have been filtered by a filter.
118 * @global array $yourls_filters storage for all of the filters
119 * @param string $hook the name of the YOURLS element or action
120 * @param mixed $value the value of the element before filtering
123 function yourls_apply_filter( $hook, $value = '' ) {
124 global $yourls_filters;
125 if ( !isset( $yourls_filters[ $hook ] ) )
128 $args = func_get_args();
130 // Sort filters by priority
131 ksort( $yourls_filters[ $hook ] );
133 // Loops through each filter
134 reset( $yourls_filters[ $hook ] );
136 foreach( (array) current( $yourls_filters[ $hook ] ) as $the_ ) {
137 if ( !is_null( $the_['function'] ) ){
139 $count = $the_['accepted_args'];
140 if ( is_null( $count ) ) {
141 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1 ) );
143 $_value = call_user_func_array( $the_['function'], array_slice( $args, 1, (int) $count ) );
146 if( $the_['type'] == 'filter' )
150 } while ( next( $yourls_filters[ $hook ] ) !== false );
152 if( $the_['type'] == 'filter' )
157 * Performs an action triggered by a YOURLS event.
159 * @param string $hook the name of the YOURLS action
160 * @param mixed $arg action arguments
162 function yourls_do_action( $hook, $arg = '' ) {
163 global $yourls_actions;
165 // Keep track of actions that are "done"
166 if ( !isset( $yourls_actions ) )
167 $yourls_actions = array();
168 if ( !isset( $yourls_actions[ $hook ] ) )
169 $yourls_actions[ $hook ] = 1;
171 ++$yourls_actions[ $hook ];
174 if ( is_array( $arg ) && 1 == count( $arg ) && isset( $arg[0] ) && is_object( $arg[0] ) ) // array(&$this)
178 for ( $a = 2; $a < func_num_args(); $a++ )
179 $args[] = func_get_arg( $a );
181 yourls_apply_filter( $hook, $args );
185 * Retrieve the number times an action is fired.
187 * @param string $hook Name of the action hook.
188 * @return int The number of times action hook <tt>$hook</tt> is fired
190 function yourls_did_action( $hook ) {
191 global $yourls_actions;
192 if ( !isset( $yourls_actions ) || !isset( $yourls_actions[ $hook ] ) )
194 return $yourls_actions[ $hook ];
198 * Removes a function from a specified filter hook.
200 * This function removes a function attached to a specified filter hook. This
201 * method can be used to remove default functions attached to a specific filter
202 * hook and possibly replace them with a substitute.
204 * To remove a hook, the $function_to_remove and $priority arguments must match
205 * when the hook was added.
207 * @global array $yourls_filters storage for all of the filters
208 * @param string $hook The filter hook to which the function to be removed is hooked.
209 * @param callback $function_to_remove The name of the function which should be removed.
210 * @param int $priority optional. The priority of the function (default: 10).
211 * @return boolean Whether the function was registered as a filter before it was removed.
213 function yourls_remove_filter( $hook, $function_to_remove, $priority = 10 ) {
214 global $yourls_filters;
216 $function_to_remove = yourls_filter_unique_id( $hook, $function_to_remove, $priority );
218 $remove = isset( $yourls_filters[ $hook ][ $priority ][ $function_to_remove ] );
220 if ( $remove === true ) {
221 unset ( $yourls_filters[$hook][$priority][$function_to_remove] );
222 if ( empty( $yourls_filters[$hook][$priority] ) )
223 unset( $yourls_filters[$hook] );
229 * Removes a function from a specified action hook.
231 * @see yourls_remove_filter()
233 * @param string $hook The action hook to which the function to be removed is hooked.
234 * @param callback $function_to_remove The name of the function which should be removed.
235 * @param int $priority optional. The priority of the function (default: 10).
236 * @return boolean Whether the function was registered as an action before it was removed.
239 function yourls_remove_action( $hook, $function_to_remove, $priority = 10 ) {
240 return yourls_remove_filter( $hook, $function_to_remove, $priority );
244 * Check if any filter has been registered for a hook.
246 * @global array $yourls_filters storage for all of the filters
247 * @param string $hook The name of the filter hook.
248 * @param callback $function_to_check optional. If specified, return the priority of that function on this hook or false if not attached.
249 * @return int|boolean Optionally returns the priority on that hook for the specified function.
251 function yourls_has_filter( $hook, $function_to_check = false ) {
252 global $yourls_filters;
254 $has = !empty( $yourls_filters[ $hook ] );
255 if ( false === $function_to_check || false == $has ) {
258 if ( !$idx = yourls_filter_unique_id( $hook, $function_to_check, false ) ) {
262 foreach ( (array) array_keys( $yourls_filters[ $hook ] ) as $priority ) {
263 if ( isset( $yourls_filters[ $hook ][ $priority ][ $idx ] ) )
269 function yourls_has_action( $hook, $function_to_check = false ) {
270 return yourls_has_filter( $hook, $function_to_check );
274 * Return number of active plugins
276 * @return integer Number of activated plugins
278 function yourls_has_active_plugins( ) {
281 if( !property_exists( $ydb, 'plugins' ) || !$ydb->plugins )
282 $ydb->plugins = array();
284 return count( $ydb->plugins );
289 * List plugins in /user/plugins
291 * @global object $ydb Storage of mostly everything YOURLS needs to know
292 * @return array Array of [/plugindir/plugin.php]=>array('Name'=>'Ozh', 'Title'=>'Hello', )
294 function yourls_get_plugins( ) {
295 $plugins = (array) glob( YOURLS_PLUGINDIR .'/*/plugin.php');
300 foreach( $plugins as $key => $plugin ) {
301 $_plugin = yourls_plugin_basename( $plugin );
302 $plugins[ $_plugin ] = yourls_get_plugin_data( $plugin );
303 unset( $plugins[ $key ] );
310 * Check if a plugin is active
312 * @param string $plugin Physical path to plugin file
315 function yourls_is_active_plugin( $plugin ) {
316 if( !yourls_has_active_plugins( ) )
320 $plugin = yourls_plugin_basename( $plugin );
322 return in_array( $plugin, $ydb->plugins );
327 * Parse a plugin header
329 * @param string $file Physical path to plugin file
330 * @return array Array of 'Field'=>'Value' from plugin comment header lines of the form "Field: Value"
332 function yourls_get_plugin_data( $file ) {
333 $fp = fopen( $file, 'r' ); // assuming $file is readable, since yourls_load_plugins() filters this
334 $data = fread( $fp, 8192 ); // get first 8kb
337 // Capture all the header within first comment block
338 if( !preg_match( '!.*?/\*(.*?)\*/!ms', $data, $matches ) )
341 // Capture each line with "Something: some text"
343 $lines = preg_split( "[\n|\r]", $matches[1] );
346 $plugin_data = array();
347 foreach( $lines as $line ) {
348 if( !preg_match( '!(.*?):\s+(.*)!', $line, $matches ) )
351 list( $null, $field, $value ) = array_map( 'trim', $matches);
352 $plugin_data[ $field ] = $value;
358 // Include active plugins
359 function yourls_load_plugins() {
360 // Don't load plugins when installing or updating
361 if( yourls_is_installing() OR yourls_is_upgrading() )
364 $active_plugins = yourls_get_option( 'active_plugins' );
365 if( false === $active_plugins )
369 $ydb->plugins = array();
371 foreach( (array)$active_plugins as $key=>$plugin ) {
372 if( yourls_validate_plugin_file( YOURLS_PLUGINDIR.'/'.$plugin ) ) {
373 include_once( YOURLS_PLUGINDIR.'/'.$plugin );
374 $ydb->plugins[] = $plugin;
375 unset( $active_plugins[$key] );
379 // $active_plugins should be empty now, if not, a plugin could not be find: remove it
380 if( count( $active_plugins ) ) {
381 yourls_update_option( 'active_plugins', $ydb->plugins );
382 $message = yourls_n( 'Could not find and deactivated plugin :', 'Could not find and deactivated plugins :', count( $active_plugins ) );
383 $missing = '<strong>'.join( '</strong>, <strong>', $active_plugins ).'</strong>';
384 yourls_add_notice( $message .' '. $missing );
389 * Check if a file is safe for inclusion (well, "safe", no guarantee)
391 * @param string $file Full pathname to a file
394 function yourls_validate_plugin_file( $file ) {
396 false !== strpos( $file, '..' )
398 false !== strpos( $file, './' )
400 'plugin.php' !== substr( $file, -10 ) // a plugin must be named 'plugin.php'
402 !is_readable( $file )
412 * @param string $plugin Plugin filename (full or relative to plugins directory)
413 * @return mixed string if error or true if success
415 function yourls_activate_plugin( $plugin ) {
417 $plugin = yourls_plugin_basename( $plugin );
418 $plugindir = yourls_sanitize_filename( YOURLS_PLUGINDIR );
419 if( !yourls_validate_plugin_file( $plugindir.'/'.$plugin ) )
420 return yourls__( 'Not a valid plugin file' );
422 // check not activated already
424 if( yourls_has_active_plugins() && in_array( $plugin, $ydb->plugins ) )
425 return yourls__( 'Plugin already activated' );
427 // attempt activation. TODO: uber cool fail proof sandbox like in WP.
429 include_once( YOURLS_PLUGINDIR.'/'.$plugin );
430 if ( ob_get_length() > 0 ) {
431 // there was some output: error
432 $output = ob_get_clean();
433 return yourls_s( 'Plugin generated unexpected output. Error was: <br/><pre>%s</pre>', $output );
437 // so far, so good: update active plugin list
438 $ydb->plugins[] = $plugin;
439 yourls_update_option( 'active_plugins', $ydb->plugins );
440 yourls_do_action( 'activated_plugin', $plugin );
441 yourls_do_action( 'activated_' . $plugin );
447 * Deactivate a plugin
449 * @param string $plugin Plugin filename (full relative to plugins directory)
450 * @return mixed string if error or true if success
452 function yourls_deactivate_plugin( $plugin ) {
453 $plugin = yourls_plugin_basename( $plugin );
455 // Check plugin is active
456 if( !yourls_is_active_plugin( $plugin ) )
457 return yourls__( 'Plugin not active' );
459 // Deactivate the plugin
461 $key = array_search( $plugin, $ydb->plugins );
462 if( $key !== false ) {
463 array_splice( $ydb->plugins, $key, 1 );
466 yourls_update_option( 'active_plugins', $ydb->plugins );
467 yourls_do_action( 'deactivated_plugin', $plugin );
468 yourls_do_action( 'deactivated_' . $plugin );
474 * Return the path of a plugin file, relative to the plugins directory
476 function yourls_plugin_basename( $file ) {
477 $file = yourls_sanitize_filename( $file );
478 $plugindir = yourls_sanitize_filename( YOURLS_PLUGINDIR );
479 $file = str_replace( $plugindir, '', $file );
480 return trim( $file, '/' );
484 * Return the URL of the directory a plugin
486 function yourls_plugin_url( $file ) {
487 $url = YOURLS_PLUGINURL . '/' . yourls_plugin_basename( $file );
488 if( yourls_is_ssl() or yourls_needs_ssl() )
489 $url = str_replace( 'http://', 'https://', $url );
490 return yourls_apply_filter( 'plugin_url', $url, $file );
494 * Display list of links to plugin admin pages, if any
496 function yourls_list_plugin_admin_pages() {
499 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
502 $plugin_links = array();
503 foreach( (array)$ydb->plugin_pages as $plugin => $page ) {
504 $plugin_links[ $plugin ] = array(
505 'url' => yourls_admin_url( 'plugins.php?page='.$page['slug'] ),
506 'anchor' => $page['title'],
509 return $plugin_links;
513 * Register a plugin administration page
515 function yourls_register_plugin_page( $slug, $title, $function ) {
518 if( !property_exists( $ydb, 'plugin_pages' ) || !$ydb->plugin_pages )
519 $ydb->plugin_pages = array();
521 $ydb->plugin_pages[ $slug ] = array(
524 'function' => $function,
529 * Handle plugin administration page
532 function yourls_plugin_admin_page( $plugin_page ) {
535 // Check the plugin page is actually registered
536 if( !isset( $ydb->plugin_pages[$plugin_page] ) ) {
537 yourls_die( yourls__( 'This page does not exist. Maybe a plugin you thought was activated is inactive?' ), yourls__( 'Invalid link' ) );
540 // Draw the page itself
541 yourls_do_action( 'load-' . $plugin_page);
542 yourls_html_head( 'plugin_page_' . $plugin_page, $ydb->plugin_pages[$plugin_page]['title'] );
546 call_user_func( $ydb->plugin_pages[$plugin_page]['function'] );
548 yourls_html_footer();
555 * Callback function: Sort plugins
557 * @link http://php.net/uasort
559 * @param array $plugin_a
560 * @param array $plugin_b
561 * @return int 0, 1 or -1, see uasort()
563 function yourls_plugins_sort_callback( $plugin_a, $plugin_b ) {
564 $orderby = yourls_apply_filter( 'plugins_sort_callback', 'Plugin Name' );
565 $order = yourls_apply_filter( 'plugins_sort_callback', 'ASC' );
567 $a = isset( $plugin_a[ $orderby ] ) ? $plugin_a[ $orderby ] : '';
568 $b = isset( $plugin_b[ $orderby ] ) ? $plugin_b[ $orderby ] : '';
573 if ( 'DESC' == $order )
574 return ( $a < $b ) ? 1 : -1;
576 return ( $a < $b ) ? -1 : 1;