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Diffstat (limited to '')
| -rw-r--r-- | BSF/include/functions_plugins.inc.php | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/BSF/include/functions_plugins.inc.php b/BSF/include/functions_plugins.inc.php new file mode 100644 index 000000000..e2beb18ac --- /dev/null +++ b/BSF/include/functions_plugins.inc.php @@ -0,0 +1,284 @@ +<?php +// +-----------------------------------------------------------------------+ +// | Piwigo - a PHP based picture gallery | +// +-----------------------------------------------------------------------+ +// | Copyright(C) 2008 Piwigo Team http://piwigo.org | +// | Copyright(C) 2003-2008 PhpWebGallery Team http://phpwebgallery.net | +// | Copyright(C) 2002-2003 Pierrick LE GALL http://le-gall.net/pierrick | +// +-----------------------------------------------------------------------+ +// | This program is free software; you can redistribute it and/or modify | +// | it under the terms of the GNU General Public License as published by | +// | the Free Software Foundation | +// | | +// | This program is distributed in the hope that it will be useful, but | +// | WITHOUT ANY WARRANTY; without even the implied warranty of | +// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | +// | General Public License for more details. | +// | | +// | You should have received a copy of the GNU General Public License | +// | along with this program; if not, write to the Free Software | +// | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, | +// | USA. | +// +-----------------------------------------------------------------------+ + +/* +Events and event handlers are the core of Piwigo plugin management. +Plugins are addons that are found in plugins subdirectory. If activated, PWG +will include the index.php of each plugin. +Events are triggered by PWG core code. Plugins (or even PWG itself) can +register their functions to handle these events. An event is identified by a +string. +*/ + +define('PHPWG_PLUGINS_PATH', PHPWG_ROOT_PATH.'plugins/'); + +define('EVENT_HANDLER_PRIORITY_NEUTRAL', 50); + +/* Register a event handler. + * @param string $event the name of the event to listen to + * @param mixed $func the function that will handle the event + * @param int $priority optional priority (greater priority will + * be executed at last) +*/ +function add_event_handler($event, $func, + $priority=EVENT_HANDLER_PRIORITY_NEUTRAL, $accepted_args=1) +{ + global $pwg_event_handlers; + + if ( isset($pwg_event_handlers[$event][$priority]) ) + { + foreach($pwg_event_handlers[$event][$priority] as $handler) + { + if ( $handler['function'] == $func ) + { + return false; + } + } + } + + $pwg_event_handlers[$event][$priority][] = + array( + 'function'=>$func, + 'accepted_args'=>$accepted_args); + ksort( $pwg_event_handlers[$event] ); + return true; +} + +/* Register a event handler. + * @param string $event the name of the event to listen to + * @param mixed $func the function that needs removal + * @param int $priority optional priority (greater priority will + * be executed at last) +*/ +function remove_event_handler($event, $func, + $priority=EVENT_HANDLER_PRIORITY_NEUTRAL) +{ + global $pwg_event_handlers; + + if (!isset( $pwg_event_handlers[$event][$priority] ) ) + { + return false; + } + for ($i=0; $i<count($pwg_event_handlers[$event][$priority]); $i++) + { + if ($pwg_event_handlers[$event][$priority][$i]['function']==$func) + { + unset($pwg_event_handlers[$event][$priority][$i]); + $pwg_event_handlers[$event][$priority] = + array_values($pwg_event_handlers[$event][$priority]); + + if ( empty($pwg_event_handlers[$event][$priority]) ) + { + unset( $pwg_event_handlers[$event][$priority] ); + if (empty( $pwg_event_handlers[$event] ) ) + { + unset( $pwg_event_handlers[$event] ); + } + } + return true; + } + } + return false; +} + +/* Triggers an event and calls all registered event handlers + * @param string $event name of the event + * @param mixed $data data to pass to handlers +*/ +function trigger_event($event, $data=null) +{ + global $pwg_event_handlers; + + // just for debugging + trigger_action('pre_trigger_event', + array('event'=>$event, 'data'=>$data) ); + + if ( !isset($pwg_event_handlers[$event]) ) + { + trigger_action('post_trigger_event', + array('event'=>$event, 'data'=>$data) ); + return $data; + } + $args = array_slice(func_get_args(), 2); + + foreach ($pwg_event_handlers[$event] as $priority => $handlers) + { + if ( !is_null($handlers) ) + { + foreach($handlers as $handler) + { + $all_args = array_merge( array($data), $args); + $function_name = $handler['function']; + $accepted_args = $handler['accepted_args']; + + if ( $accepted_args == 1 ) + $the_args = array($data); + elseif ( $accepted_args > 1 ) + $the_args = array_slice($all_args, 0, $accepted_args); + elseif ( $accepted_args == 0 ) + $the_args = NULL; + else + $the_args = $all_args; + + $data = call_user_func_array($function_name, $the_args); + } + } + } + trigger_action('post_trigger_event', + array('event'=>$event, 'data'=>$data) ); + return $data; +} + +function trigger_action($event, $data=null) +{ + global $pwg_event_handlers; + if ($event!='pre_trigger_event' + and $event!='post_trigger_event' + and $event!='trigger_action') + {// special case for debugging - avoid recursive calls + trigger_action('trigger_action', + array('event'=>$event, 'data'=>$data) ); + } + + if ( !isset($pwg_event_handlers[$event]) ) + { + return; + } + $args = array_slice(func_get_args(), 2); + + foreach ($pwg_event_handlers[$event] as $priority => $handlers) + { + if ( !is_null($handlers) ) + { + foreach($handlers as $handler) + { + $all_args = array_merge( array($data), $args); + $function_name = $handler['function']; + $accepted_args = $handler['accepted_args']; + + if ( $accepted_args == 1 ) + $the_args = array($data); + elseif ( $accepted_args > 1 ) + $the_args = array_slice($all_args, 0, $accepted_args); + elseif ( $accepted_args == 0 ) + $the_args = NULL; + else + $the_args = $all_args; + + call_user_func_array($function_name, $the_args); + } + } + } +} + +/** Saves some data with the associated plugim id. It can be retrieved later ( + * during this script lifetime) using get_plugin_data + * @param string plugin_id + * @param mixed data + * returns true on success, false otherwise + */ +function set_plugin_data($plugin_id, &$data) +{ + global $pwg_loaded_plugins; + if ( isset($pwg_loaded_plugins[$plugin_id]) ) + { + $pwg_loaded_plugins[$plugin_id]['plugin_data'] = &$data; + return true; + } + return false; +} + +/** Retrieves plugin data saved previously with set_plugin_data + * @param string plugin_id + */ +function &get_plugin_data($plugin_id) +{ + global $pwg_loaded_plugins; + if ( isset($pwg_loaded_plugins[$plugin_id]) ) + { + return $pwg_loaded_plugins[$plugin_id]['plugin_data']; + } + return null; +} + +/* Returns an array of plugins defined in the database + * @param string $state optional filter on this state + * @param string $id optional returns only data about given plugin +*/ +function get_db_plugins($state='', $id='') +{ + $query = ' +SELECT * FROM '.PLUGINS_TABLE; + if (!empty($state) or !empty($id) ) + { + $query .= ' +WHERE 1=1'; + if (!empty($state)) + { + $query .= ' + AND state="'.$state.'"'; + } + if (!empty($id)) + { + $query .= ' + AND id="'.$id.'"'; + } + } + + $result = pwg_query($query); + $plugins = array(); + while ($row = mysql_fetch_array($result)) + { + array_push($plugins, $row); + } + return $plugins; +} + + +function load_plugin($plugin) +{ + $file_name = PHPWG_PLUGINS_PATH.$plugin['id'].'/main.inc.php'; + if ( file_exists($file_name) ) + { + global $pwg_loaded_plugins; + $pwg_loaded_plugins[ $plugin['id'] ] = $plugin; + include_once( $file_name ); + } +} + +/*loads all the plugins on startup*/ +function load_plugins() +{ + global $conf, $pwg_loaded_plugins; + $pwg_loaded_plugins = array(); + if ($conf['enable_plugins']) + { + $plugins = get_db_plugins('active'); + foreach( $plugins as $plugin) + {// include main from a function to avoid using same function context + load_plugin($plugin); + } + trigger_action('plugins_loaded'); + } +} +?>
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