event_manager.inc

<?php
class Event_Manager extends MySource_Object
{

    var $_runtime_event_listeners = Array();

    var $_runtime_listener_objects = Array();

    function Event_Manager()
    {
        parent::MySource_Object();

    }//end constructor


    function addEventListener(&$listener, $events=Array(), $broadcast_polling_events=true)
    {
        if (empty($events)) return false;

        foreach ($events as $event_name) {
            $event_name = trim($event_name);
            if (empty($event_name)) continue;

            if (!array_key_exists($event_name, $this->_runtime_event_listeners)) {
                $this->_runtime_event_listeners[$event_name] = Array();
            }
            $index = count($this->_runtime_listener_objects);
            $this->_runtime_listener_objects[] = $listener;
            $this->_runtime_event_listeners[$event_name][$index] = true;
        }
        return true;

    }//end addEventListener()


    function _broadcastRuntimeEvents(&$broadcaster, $event_name, $vars=Array())
    {
        if (!isset($this->_runtime_event_listeners[$event_name])) {
            return false;
        }

        $event_name = trim($event_name);
        $function_name = 'on'.$event_name;

        foreach (array_keys($this->_runtime_event_listeners[$event_name]) as $index) {
            if (!isset($this->_runtime_listener_objects[$index])) {
                continue;
            }
            $listener = $this->_runtime_listener_objects[$index];
            if (is_null($listener)) continue;
            if (!method_exists($listener, $function_name)) {
                continue;
            }
            $listener->$function_name($broadcaster, $vars);
        }

        return true;

    }//end _broadcastRuntimeEvents()


    function broadcastEvent(&$broadcaster, $event_name='', $vars=Array())
    {

        // note: event names should be cammel topped (first letter of each word is a capital, excluding the first word).
        // the listener needs to have a function of the event name prepended with 'on'
        // eg. for an event name contentsUpdated the listener needs a function called onContentsUpdated()
        // The function needs to accept an array in the arguments list (for vars)

        // check the runtime events first
        $this->_broadcastRuntimeEvents($broadcaster, $event_name, $vars);

        // create a temp entry for the event listeners (runtime wide as event_manager is cached)
        if (!isset($this->_tmp['event_listeners'])) {
            $this->_loadCachedEventListeners();
        }

        // we don't have an entry for this event
        if (!isset($this->_tmp['event_listeners']['global'][$event_name]) && !isset($this->_tmp['event_listeners'][strtolower(get_class($broadcaster))][$event_name])) {
            return false;
        }

        $listeners = Array();
        $listener_codes = Array();

        if (isset($this->_tmp['event_listeners']['global'][$event_name])) {
            $listener_codes += $this->_tmp['event_listeners']['global'][$event_name];
        }
        if (isset($this->_tmp['event_listeners'][get_class_lower($broadcaster)][$event_name])) {
            $listener_codes += $this->_tmp['event_listeners'][get_class_lower($broadcaster)][$event_name];
        }

        $possible_listeners_parents = array();
        $possible_listeners_children = array();

        foreach ($listener_codes as $listener_type_code => $options) {
            // these $options never seem to be set, force them to be set to avoid notices from PHP
            if (empty($options['type_code'])) {
                $options['type_code'] = '';
            }
            if (empty($options['strict_type_code'])) {
                $options['strict_type_code'] = false;
            }
            if (empty($options['global'])) {
                $options['global'] = false;
            }

            $side_of_link = (isset($options['side_of_link']) && ($options['side_of_link'] == 'minor')) ? 'major' : 'minor';

            if ($options['global']) {
                // Global: all global events should be heard even if outside the chain
                $assetids = $GLOBALS['SQ_SYSTEM']->am->getTypeAssetids($listener_type_code, true);
            } else if ($options['indirect']) {

                // no point continuing if this object does not inherit from asset
                if (!($broadcaster instanceof asset)) return true;
                if (!$broadcaster->id) return;

                // let's not query the tree unless we have to
                if ($options['is_dependant'] && !$options['is_exclusive']) {
                    if (isset($found_listener)) {
                        continue;
                    }

                    // do this until one of the returned assets matches a listener type code
                    if ($side_of_link === 'minor') {
                        if (empty($possible_listeners_parents)) {
                            $possible_listeners_parents = $GLOBALS['SQ_SYSTEM']->am->getDependantParents($broadcaster->id);
                        }
                        $possible_listeners = $possible_listeners_parents;
                    } else {
                        if (empty($possible_listeners_children)) {
                            $possible_listeners_children = $GLOBALS['SQ_SYSTEM']->am->getDependantChildren($broadcaster->id);
                        }
                        $possible_listeners = $possible_listeners_children;
                    }

                    // get type codes of our assetids (only need to do it once)
                    if (!isset($types)) {
                        for ($i=0; $i<count($possible_listeners); $i++) {
                            $asset = $GLOBALS['SQ_SYSTEM']->am->getAsset($possible_listeners[$i]);
                            $types[$possible_listeners[$i]] = $asset->type();
                        }
                    }

                } else if ($options['is_dependant'] || $options['is_exclusive'] || $options['type_code']) {
                    $assetids = $this->_getDiscreteAssets($broadcaster->id, $listener_type_code, $side_of_link, $options);
                } else {

                    // this is in the reverse to what is normal.
                    // eg. if a form wants to listen to events broadcasted from a bodycopy (which is a child of the form)
                    // then the form wants to hear from minor. When the bodycopy broadcasts, the form is on the major of
                    // the bodycopy, comprende?

                    $function = 'get'.(($options['side_of_link'] == 'minor') ? 'Parents' : 'Children');
                    $assetids = $GLOBALS['SQ_SYSTEM']->am->$function($broadcaster->id, $listener_type_code, $options['strict_type_code']);
                    if (empty($assetids)) continue;
                }

            } else {

                $links = $GLOBALS['SQ_SYSTEM']->am->getLinks($broadcaster->id, $options['link_type'], $listener_type_code, true, $options['side_of_link'], $options['value'], $options['is_dependant'], $options['is_exclusive']);
                if (empty($links)) continue;

                $assetids = Array();
                foreach ($links as $link) {
                    $assetids[] = $link[$side_of_link.'id'];
                }

            }// end if

            // are we filtering our listeners?
            if (isset($types)) {
                // get our listener
                if (in_array($listener_type_code, $types)) {
                    foreach ($types as $assetid => $type_code) {
                        if ($type_code === $listener_type_code) {
                            $found_listener = TRUE;
                            $asset = $GLOBALS['SQ_SYSTEM']->am->getAsset($assetid);
                            if (is_null($asset)) continue;
                            $listeners[] = $asset;
                        }
                    }
                }
            } else {
                foreach ($assetids as $assetid) {
                    $asset = $GLOBALS['SQ_SYSTEM']->am->getAsset($assetid);
                    if (is_null($asset)) continue;
                    $listeners[] = $asset;
                }
            }

        }// end foreach

        if (empty($listeners)) return false;

        $function = 'on'.$event_name;
        for (reset($listeners); null !== ($key = key($listeners)); next($listeners)) {
            $listener = $listeners[$key];
            if (!method_exists($listener, $function)) {
                trigger_localised_error('SYS0127', E_USER_WARNING, $function, $listener->type(), $asset->id);
                return false;
            }
            $listener->$function($broadcaster, $vars);
            $GLOBALS['SQ_SYSTEM']->am->forgetAsset($listener);
        }// end for

        return true;

    }//end broadcastEvent()


    function _getDiscreteAssets($assetid='', $type_code='', $side_of_link='minor', $info=Array())
    {
        if (empty($assetid) || empty($type_code)) {
            return Array();
        }

        $sql = 'SELECT (t2.treeid || \'%\')
                FROM sq_ast_lnk l1
                  INNER JOIN sq_ast_lnk_tree t1 ON l1.linkid = t1.linkid,
                  sq_ast_lnk l2
                  INNER JOIN sq_ast_lnk_tree t2 ON l2.linkid = t2.linkid,
                  sq_ast a
                WHERE l1.'.$side_of_link.'id = :assetid
                  AND SUBSTR(t1.treeid, 1, LENGTH(t2.treeid)) = t2.treeid
                  AND a.assetid=l2.'.$side_of_link.'id
                  AND a.type_code= :type_code
                ORDER BY t2.treeid DESC';

        $result = NULL;
        try {
            $query = MatrixDAL::preparePdoQuery($sql);
            MatrixDAL::bindValueToPdo($query, 'assetid', $assetid);
            MatrixDAL::bindValueToPdo($query, 'type_code', $type_code);
            $result = MatrixDAL::executePdoAssoc($query, 0);
        } catch (Exception $e) {
            throw new Exception('Unable to get Discrete Assets due to database error: '.$e->getMessage());
        }

        if (empty($result)) return Array();

        $treeid_string = '';
        foreach ($result as $treeid) {
            $treeid_string .= 't2.treeid LIKE \''.$treeid.'\' OR ';
        }
        $treeid_string = substr($treeid_string, 0, -4);


        $sql = 'SELECT a.assetid, t2.treeid, a.type_code, l2.link_type, l2.is_dependant, l2.is_exclusive
                FROM sq_ast_lnk l1
                  INNER JOIN sq_ast_lnk_tree t1 ON l1.linkid = t1.linkid,
                  sq_ast_lnk l2
                  INNER JOIN sq_ast_lnk_tree t2 ON l2.linkid = t2.linkid,
                  sq_ast a
                WHERE l1.'.$side_of_link.'id = :assetid
                    AND SUBSTR(t1.treeid, 1, LENGTH(t2.treeid)) = t2.treeid
                    AND a.assetid = l2.'.$side_of_link.'id
                    AND ('.$treeid_string.')
                ORDER BY t2.treeid';

        $result = NULL;

        try {
            $query = MatrixDAL::preparePdoQuery($sql);
            MatrixDAL::bindValueToPdo($query, 'assetid', $assetid);
            $result = MatrixDAL::executePdoAll($query);
        } catch (Exception $e) {
            throw new Exception('Unable to get Discrete Assets due to database error: '.$e->getMessage());
        }//end try

        $assetids = Array();
        $start_treeid = true;
        $popped_treeid = false;

        for ($i = 0; $i < count($result); $i++) {

            if (isset($result[$i+1]) && strpos($result[$i+1]['treeid'], $result[$i]['treeid']) === false) {

                // the next treeid is not based on our treeid, so we will be starting a new branch
                $start_treeid = true;
                $popped_treeid = false;

            } else {

                if (!$popped_treeid) {

                    if (in_array($result[$i]['assetid'], $assetids)) {
                        // we have already approved this asset to get notified
                        // so lets skip the rest of the branch
                        $popped_treeid = true;
                        continue;
                    }

                    if ($side_of_link == 'minor') {
                        if (!isset($result[$i +1])) continue;
                        $test_info = $result[$i +1];
                    } else {
                        $test_info = $result[$i];
                    }

                    $valid_assetid = true;
                    if ($valid_assetid && $info['value'] && $info['value'] != $test_info['value']) {
                        $valid_assetid = false;
                    }
                    if ($valid_assetid && !$test_info['is_dependant'] && $info['is_dependant']) {
                        $valid_assetid = false;
                    }
                    if ($valid_assetid && !$test_info['is_exclusive'] && $info['is_exclusive']) {
                        $valid_assetid = false;
                    }
                    if ($valid_assetid &&  $test_info['link_type'] &  $info['link_type'] <= 0) {
                        $valid_assetid = false;
                    }

                    if ($start_treeid && $valid_assetid) {
                        $assetids[] = $result[$i]['assetid'];
                        $start_treeid = false;
                    } else if (!$start_treeid && !$valid_assetid) {
                        // the last assetid we added failed the test, so get rid of it
                        array_pop($assetids);
                        $popped_treeid = true;
                    }

                }//end if !$popped_treeid

            }//end if not starting again next time around

        }//end for

        return $assetids;

    }//end _getDiscreteAssets()


    function writeStaticEventsCacheFile()
    {
        if (!isset($this->_tmp['event_listeners']) || empty($this->_tmp['event_listeners'])) {
            return false;
        }

        $output = '<'.'?php'."\n".' $cached_event_listeners_array = ';
        $output .= var_export($this->_tmp['event_listeners'], true);
        $output .= "\n?".'>';

        if (!string_to_file($output, SQ_DATA_PATH.'/private/events/event_listeners.inc')) {
            return false;
        }
        unset($this->_tmp['event_listeners']);

        return true;

    }//end writeStaticEventsCacheFile()


    function installStaticEvents($listeners=Array(), $listener_type_code='', $recursive_call=false)
    {
        if (!is_array($listeners)|| empty($listeners)) {
            return false;
        }
        if (!isset($this->_tmp['event_listeners'])) {
            $this->_loadCachedEventListeners();
        }

        $listener_name = Array();
        foreach ($listeners as $index => $info) {
            if (!isset($this->_tmp['event_listeners'][$info['broadcast_type_code']])) {
                $this->_tmp['event_listeners'][$info['broadcast_type_code']] = Array();
            }
            if (!isset($this->_tmp['event_listeners'][$info['broadcast_type_code']][$info['event_name']])) {
                $this->_tmp['event_listeners'][$info['broadcast_type_code']][$info['event_name']] = Array();
            }

            // if they have been lazy, do some cleanup
            if (!isset($info['options']['value'])) {
                $info['options']['value'] = '';
            }

            if (!is_array($info['options'])) {
                trigger_localised_error('SYS0143', E_USER_WARNING, $listener_type_code, gettype($info['options']));
                return false;
            }

            $this->_tmp['event_listeners'][$info['broadcast_type_code']][$info['event_name']][$listener_type_code] = $info['options'];

            // if the broadcast type code can be of multiple types, then we have to add some more
            // entries for these in the array
            if (!$info['broadcast_strict_type_code'] && !$recursive_call) {
                // only broadcast if the listener is installed, fail silently
                if ($GLOBALS['SQ_SYSTEM']->am->installed($info['broadcast_type_code'])) {
                    $type_codes = $GLOBALS['SQ_SYSTEM']->am->getTypeDescendants($info['broadcast_type_code']);
                    if (empty($type_codes)) continue;
                    foreach ($type_codes as $type_code) {
                        $info['broadcast_type_code'] = $type_code;
                        $this->installStaticEvents(Array($info), $listener_type_code, true);
                    }
                }
            }
            $listener_name[] = $info['event_name'];
        }

        // done with everything ?
        // remove any of the listeners that might have been deleted from our asset
        foreach ($this->_tmp['event_listeners'] as $broadcast_type_code => $listener_info) {
            foreach ($listener_info as $name => $asset_array) {
                foreach ($asset_array as $asset_type => $info) {
                    if ($asset_type == $listener_type_code && !in_array($name, $listener_name)) {
                        unset($this->_tmp['event_listeners'][$broadcast_type_code][$name][$asset_type]);
                    }
                }
            }
        }

        return true;

    }//end installStaticEvents()


    function _loadCachedEventListeners()
    {
        if (!file_exists(SQ_DATA_PATH.'/private/events/event_listeners.inc')) {
            $this->_tmp['event_listeners'] = Array();
            return;
        }
        require SQ_DATA_PATH.'/private/events/event_listeners.inc';
        if (!isset($cached_event_listeners_array)) {
            trigger_error('Failed loading event listeners from SQ_DATA_PATH/private/events/event_listeners.inc; Event listeners file may be corrupt', E_USER_ERROR);
            return;
        }
        $this->_tmp['event_listeners'] = $cached_event_listeners_array;

    }//end _loadCachedEventListeners()


}//end class
?>