git-svn-id: http://piwigo.org/svn/trunk@2357 68402e56-0260-453c-a942-63ccdbb3a9ee

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
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+++ 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');
+  }
+}
+?>
\ No newline at end of file