--- a/include/common-transit.inc.php
+++ b/include/common-transit.inc.php
@@ -1,260 +1,339 @@
 <?php
+
+/*
+ *    Copyright 2010,2011 Alexander Sadleir 
+
+  Licensed under the Apache License, Version 2.0 (the 'License');
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an 'AS IS' BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+ */
 $service_periods = Array(
-	'sunday',
-	'saturday',
-	'weekday'
+    'sunday',
+    'saturday',
+    'weekday'
 );
 
-function service_period($date = "")
-{
-	
-	if (isset($_SESSION['service_period'])) return $_SESSION['service_period'];
-	$override = getServiceOverride($date);
-	if ($override['service_id']){
-		return $override['service_id'];
-	}
-
-	switch (date('w',($date != "" ? $date : time()))) {
-	case 0:
-		return 'sunday';
-	case 6:
-		return 'saturday';
-	default:
-		return 'weekday';
-	}
-}
-function midnight_seconds($time = "")
-{
-	// from http://www.perturb.org/display/Perlfunc__Seconds_Since_Midnight.html
-	if ($time != "") {
-		return (date("G", $time) * 3600) + (date("i", $time) * 60) + date("s", $time);
-	}
-	if (isset($_SESSION['time'])) {
-		$time = strtotime($_SESSION['time']);
-		return (date("G", $time) * 3600) + (date("i", $time) * 60) + date("s", $time);
-	}
-	return (date("G") * 3600) + (date("i") * 60) + date("s");
-}
-function midnight_seconds_to_time($seconds)
-{
-	if ($seconds > 0) {
-		$midnight = mktime(0, 0, 0, date("n") , date("j") , date("Y"));
-		return date("h:ia", $midnight + $seconds);
-	}
-	else {
-		return "";
-	}
-}
+function service_period($date = '') {
+
+    if (isset($_REQUEST['service_period'])) {
+        return $_REQUEST['service_period'];
+    }
+
+    $override = getServiceOverride($date);
+    if (isset($override['service_id'])) {
+        return strtolower($override['service_id']);
+    }
+    $date = ($date != '' ? $date : time());
+    $dow = date('w', $date);
+
+    switch ($dow) {
+        case 0:
+            return 'sunday';
+        case 6:
+            return 'saturday';
+        default:
+            return 'weekday';
+    }
+}
+
+function service_ids($service_period, $date = '') {
+    switch ($service_period) {
+        case 'sunday':
+            return Array('Sunday', 'Sunday');
+        case 'saturday':
+            return Array('Saturday', 'Saturday');
+        default:
+            $date = ($date != '' ? $date : time());
+// school holidays
+            $ymd = date('Ymd', $date);
+            $dow = date('w', $date);
+            if (intval($ymd) < '20120203' && $dow != 0 && $dow != 6) {
+                return Array('Weekday-SchoolVacation', 'Weekday-SchoolVacation');
+            } else {
+                return Array('Weekday', 'Weekday');
+            }
+    }
+}
+
+function valid_service_ids() {
+    return array_merge(service_ids(''), service_ids('saturday'), service_ids('sunday'));
+}
+
+function midnight_seconds($time = '') {
+    // from http://www.perturb.org/display/Perlfunc__Seconds_Since_Midnight.html
+    if ($time != '') {
+        return (date('G', $time) * 3600) + (date('i', $time) * 60) + date('s', $time);
+    }
+    if (isset($_SESSION['time'])) {
+        $time = strtotime($_SESSION['time']);
+        return (date('G', $time) * 3600) + (date('i', $time) * 60) + date('s', $time);
+    }
+    return (date('G') * 3600) + (date('i') * 60) + date('s');
+}
+
+function midnight_seconds_to_time($seconds) {
+    if ($seconds > 0) {
+        $midnight = mktime(0, 0, 0, date('n'), date('j'), date('Y'));
+        return date('h:ia', $midnight + $seconds);
+    } else {
+        return '';
+    }
+}
+
 if ($GTFSREnabled) {
-$serviceAlertCause = Array(
-"UNKNOWN_CAUSE" => "Unknown cause",
-"OTHER_CAUSE" => "Other cause",
-"TECHNICAL_PROBLEM" => "Technical problem",
-"STRIKE" => "Strike",
-"DEMONSTRATION" => "Demonstration",
-"ACCIDENT" => "Accident",
-"HOLIDAY" => "Holiday",
-"WEATHER" => "Weather",
-"MAINTENANCE" => "Maintenance",
-"CONSTRUCTION" => "Construction",
-"POLICE_ACTIVITY" => "Police activity",
-"MEDICAL_EMERGENCY" => "Medical emergency"
-);
-$serviceAlertEffect = Array(
-"NO_SERVICE" => "No service",
-"REDUCED_SERVICE" => "Reduced service",
-"SIGNIFICANT_DELAYS" => "Significant delays",
-"DETOUR" => "Detour",
-"ADDITIONAL_SERVICE" => "Additional service",
-"MODIFIED_SERVICE" => "Modified service",
-"OTHER_EFFECT" => "Other effect",
-"UNKNOWN_EFFECT" => "Unknown effect",
-"STOP_MOVED" => "Stop moved");
-
-set_include_path(get_include_path() . PATH_SEPARATOR . $labsPath."lib/Protobuf-PHP/library/DrSlump/");
-
-include_once("Protobuf.php");
-include_once("Protobuf/Message.php");
-include_once("Protobuf/Registry.php");
-include_once("Protobuf/Descriptor.php");
-include_once("Protobuf/Field.php");
-
-include_once($labsPath."lib/Protobuf-PHP/gtfs-realtime.php");
-include_once("Protobuf/CodecInterface.php");
-include_once("Protobuf/Codec/PhpArray.php");
-include_once("Protobuf/Codec/Binary.php");
-include_once("Protobuf/Codec/Binary/Writer.php");
-include_once("Protobuf/Codec/Json.php");
-
-function getServiceAlerts($filter_class = "", $filter_id = "") {
-/*
-
-  also need last modified epoch of client gtfs
-  
-         - add,remove,patch,inform (null)
-            - stop
-            - trip
-            - network
+    $serviceAlertCause = Array(
+        'UNKNOWN_CAUSE' => 'Unknown cause',
+        'OTHER_CAUSE' => 'Other cause',
+        'TECHNICAL_PROBLEM' => 'Technical problem',
+        'STRIKE' => 'Strike',
+        'DEMONSTRATION' => 'Demonstration',
+        'ACCIDENT' => 'Accident',
+        'HOLIDAY' => 'Holiday',
+        'WEATHER' => 'Weather',
+        'MAINTENANCE' => 'Maintenance',
+        'CONSTRUCTION' => 'Construction',
+        'POLICE_ACTIVITY' => 'Police activity',
+        'MEDICAL_EMERGENCY' => 'Medical emergency'
+    );
+    $serviceAlertEffect = Array(
+        'NO_SERVICE' => 'No service',
+        'REDUCED_SERVICE' => 'Reduced service',
+        'SIGNIFICANT_DELAYS' => 'Significant delays',
+        'DETOUR' => 'Detour',
+        'ADDITIONAL_SERVICE' => 'Additional service',
+        'MODIFIED_SERVICE' => 'Modified service',
+        'OTHER_EFFECT' => 'Other effect',
+        'UNKNOWN_EFFECT' => 'Unknown effect',
+        'STOP_MOVED' => 'Stop moved');
+
+    set_include_path(get_include_path() . PATH_SEPARATOR . (ROOT. '/../lib/Protobuf-PHP/library/DrSlump/'));
+
+    include_once('Protobuf.php');
+    include_once('Protobuf/Message.php');
+    include_once('Protobuf/Registry.php');
+    include_once('Protobuf/Descriptor.php');
+    include_once('Protobuf/Field.php');
+
+    include_once(ROOT. '/../lib/Protobuf-PHP/gtfs-realtime.php');
+    include_once('Protobuf/CodecInterface.php');
+    include_once('Protobuf/Codec/PhpArray.php');
+    include_once('Protobuf/Codec/Binary.php');
+    include_once('Protobuf/Codec/Binary/Writer.php');
+    include_once('Protobuf/Codec/Json.php');
+
+    function getServiceAlerts($filter_class = '', $filter_id = '') {
+        /*
+
+          also need last modified epoch of client gtfs
+
+          - add,remove,patch,inform (null)
+          - stop
+          - trip
+          - network
           - classes (WHERE=)
-            - route (short_name or route_id)
-            - street
-            - stop
-            - trip 
-            Currently support:
-            network inform
-            trip patch: stop remove
-            street inform: route inform, trip inform, stop inform
-            route patch: trip remove
-            */
+          - route (short_name or route_id)
+          - street
+          - stop
+          - trip
+          Currently support:
+          network inform
+          trip patch: stop remove
+          street inform: route inform, trip inform, stop inform
+          route patch: trip remove
+         */
+        $current_alerts = getCurrentAlerts();
+        $informed_count = 0;
+        if (sizeof($current_alerts) > 0) {
+
             $fm = new transit_realtime\FeedMessage();
-$fh = new transit_realtime\FeedHeader();
-$fh->setGtfsRealtimeVersion(1);
-$fh->setTimestamp(time());
-$fm->setHeader($fh);
-foreach(getCurrentAlerts() as $alert) {
-$fe = new transit_realtime\FeedEntity();
-	$fe->setId($alert['id']);
-	$fe->setIsDeleted(false);
-	$alert = new transit_realtime\Alert();	
-		$tr = new transit_realtime\TimeRange();
-			$tr->setStart($alert['start']);
-			$tr->setEnd($alert['end']);
-		$alert-> addActivePeriod($tr);
-			$informedEntities = getInformedAlerts($alert['id'],$_REQUEST['filter_class'],$_REQUEST['filter_id']);
-	if (sizeof($informedEntities) >0) {
-		$informed = Array();
-		$es = new transit_realtime\EntitySelector();
-		if ($informedEntity['informed_class'] == "agency") {
-			$es->setAgencyId($informedEntity['informed_id']);
-		}
-		if ($informedEntity['informed_class'] == "stop") {
-			$es->setStopId($informedEntity['informed_id']);
-		}
-		if ($informedEntity['informed_class'] == "route") {
-			$es->setRouteId($informedEntity['informed_id']);
-		}
-		if ($informedEntity['informed_class'] == "trip") {
-			$td = new transit_realtime\TripDescriptor();
-				$td->setTripId($informedEntity['informed_id']);
-			$es->setTrip($td);
-		}
-		$alert-> addInformedEntity($es);
-	}
-		$alert->setCause(constant("transit_realtime\Alert\Cause::".$alert['cause']));
-		$alert->setEffect(constant("transit_realtime\Alert\Effect::".$alert['effect']));
-		$tsUrl = new transit_realtime\TranslatedString();
-			$tUrl = new transit_realtime\TranslatedString\Translation();
-				$tUrl->setText($alert['url']);
-				$tUrl->setLanguage("en");
-			$tsUrl->addTranslation($tUrl);
-		$alert->setUrl($tsUrl);
-		$tsHeaderText= new transit_realtime\TranslatedString();
-			$tHeaderText = new transit_realtime\TranslatedString\Translation();
-				$tHeaderText->setText($alert['header']);
-				$tHeaderText->setLanguage("en");
-			$tsHeaderText->addTranslation($tHeaderText);
-		$alert->setHeaderText($tsHeaderText);
-		$tsDescriptionText= new transit_realtime\TranslatedString();
-			$tDescriptionText = new transit_realtime\TranslatedString\Translation();
-				$tDescriptionText->setText($alert['description']);
-				$tDescriptionText->setLanguage("en");
-			$tsDescriptionText->addTranslation($tDescriptionText);
-		$alert->setDescriptionText($tsDescriptionText);
-	$fe->setAlert($alert);
-$fm->addEntity($fe);
-}
-return $fm;
-}
-function getServiceAlertsAsArray($filter_class = "", $filter_id = "") {
-	$codec = new DrSlump\Protobuf\Codec\PhpArray();
-	return $codec->encode(getServiceAlerts($filter_class, $filter_id));
-}
-
-function getServiceAlertsAsBinary($filter_class = "", $filter_id = "") {
-	$codec = new DrSlump\Protobuf\Codec\Binary();
-	return $codec->encode(getServiceAlerts($filter_class, $filter_id));
-}
-
-function getServiceAlertsAsJSON($filter_class = "", $filter_id = "") {
-	$codec = new DrSlump\Protobuf\Codec\Json();
-	return $codec->encode(getServiceAlerts($filter_class, $filter_id));
-}
-function getServiceAlertsByClass() {
-	$return = Array();
-	$alerts = getServiceAlertsAsArray("","");
-	foreach ($alerts['entities'] as $entity) {
-		foreach ($entity['informed'] as $informed) {
-			foreach($informed as $key => $value){
-				if (strpos("_id",$key) > 0) {
-					$parts = explode($key);
-					$class = $parts[0];
-					$id = $value;
-				}
-			}
-		$return[$class][$id][] = $entity;
-	}
-	}
-}
-
-function getTripUpdates($filter_class = "", $filter_id = "") {
-     $fm = new transit_realtime\FeedMessage();
-$fh = new transit_realtime\FeedHeader();
-$fh->setGtfsRealtimeVersion(1);
-$fh->setTimestamp(time());
-$fm->setHeader($fh);
-foreach(getCurrentAlerts() as $alert) {
-			$informedEntities = getInformedAlerts($alert['id'],$_REQUEST['filter_class'],$_REQUEST['filter_id']);
-	$stops = Array();
-		$routestrips = Array();
-		if (sizeof($informedEntities) >0) {
-		if ($informedEntity['informed_class'] == "stop" && $informed["x-action"] == "remove") {
-			$stops[] = $informedEntity['informed_id'];
-		}
-		if (($informedEntity['informed_class'] == "route" || $informedEntity['informed_class'] == "trip") && $informed["x-action"] == "patch" ) {
-			$routestrips[] = Array( "id" => $informedEntity['informed_id'],
-			"type"=>$informedEntity['informed_class']);
-		}
-		}
-foreach ($routestrips as $routetrip) {
-$fe = new transit_realtime\FeedEntity();
-	$fe->setId($alert['id'].$routetrip['id']);
-	$fe->setIsDeleted(false);
-	$tu = new transit_realtime\TripUpdate();	
-		$td = new transit_realtime\TripDescriptor();
-		if ($routetrip['type'] == "route") {
-			$td->setRouteId($routetrip['id']);
-			} else if ($routetrip['type'] == "trip") {
-				$td->setTripId($routetrip['id']);
-			}
-		$tu->setTrip($td);
-		foreach ($stops as $stop) {
-		$stu = new transit_realtime\TripUpdate\StopTimeUpdate();
-				$stu->setStopId($stop);
-				$stu->setScheduleRelationship(transit_realtime\TripUpdate\StopTimeUpdate\ScheduleRelationship::SKIPPED);
-		$tu->addStopTimeUpdate($stu);
-	}
-	$fe->setTripUpdate($tu);
-$fm->addEntity($fe);
-}		
-
-}
-return $fm;
-	
-}
-function getTripUpdatesAsArray($filter_class = "", $filter_id = "") {
-	$codec = new DrSlump\Protobuf\Codec\PhpArray();
-	return $codec->encode(getTripUpdates($filter_class, $filter_id));
-}
-
-function getTripUpdatesAsBinary($filter_class = "", $filter_id = "") {
-	$codec = new DrSlump\Protobuf\Codec\Binary();
-	return $codec->encode(getTripUpdates($filter_class, $filter_id));
-}
-
-function getTripUpdatesAsJSON($filter_class = "", $filter_id = "") {
-	$codec = new DrSlump\Protobuf\Codec\Json();
-	return $codec->encode(getTripUpdates($filter_class, $filter_id));
-}
-}
-?>
-
+            $fh = new transit_realtime\FeedHeader();
+            $fh->setGtfsRealtimeVersion(1);
+            $fh->setTimestamp(time());
+            $fm->setHeader($fh);
+            foreach ($current_alerts as $current_alert) {
+                $affectsFilteredEntities = false;
+                $fe = new transit_realtime\FeedEntity();
+                $fe->setId($current_alert['id']);
+                $fe->setIsDeleted(false);
+                $alert = new transit_realtime\Alert();
+                $tr = new transit_realtime\TimeRange();
+                $tr->setStart($current_alert['start']);
+                $tr->setEnd($current_alert['end']);
+                $alert->addActivePeriod($tr);
+                $informedEntities = getInformedAlerts($current_alert['id'], $filter_class, $filter_id);
+                if (sizeof($informedEntities) > 0) {
+
+                    $affectsFilteredEntities = true;
+                    foreach ($informedEntities as $informedEntity) {
+	$informed_count++;
+                    $informed = Array();
+                    $es = new transit_realtime\EntitySelector();
+                    if ($informedEntity['informed_class'] == 'agency') {
+                        $es->setAgencyId($informedEntity['informed_id']);
+                    }
+                    if ($informedEntity['informed_class'] == 'stop') {
+                        $es->setStopId($informedEntity['informed_id']);
+                    }
+                    if ($informedEntity['informed_class'] == 'route') {
+                        $es->setRouteId($informedEntity['informed_id']);
+                    }
+                    if ($informedEntity['informed_class'] == 'trip') {
+                        $td = new transit_realtime\TripDescriptor();
+                        $td->setTripId($informedEntity['informed_id']);
+                        $es->setTrip($td);
+                    }
+                    $alert->addInformedEntity($es);
+}
+                }
+                if ($current_alert['cause'] != '') {
+                    $alert->setCause(constant('transit_realtime\Alert\Cause::' . $current_alert['cause']));
+                }
+                if ($current_alert['effect'] != '') {
+                    $alert->setEffect(constant('transit_realtime\Alert\Effect::' . $current_alert['effect']));
+                }
+                if ($current_alert['url'] != '') {
+                    $tsUrl = new transit_realtime\TranslatedString();
+                    $tUrl = new transit_realtime\TranslatedString\Translation();
+                    $tUrl->setText($current_alert['url']);
+                    $tUrl->setLanguage('en');
+                    $tsUrl->addTranslation($tUrl);
+                    $alert->setUrl($tsUrl);
+                }
+                if ($current_alert['header'] != '') {
+                    $tsHeaderText = new transit_realtime\TranslatedString();
+                    $tHeaderText = new transit_realtime\TranslatedString\Translation();
+                    $tHeaderText->setText($current_alert['header']);
+                    $tHeaderText->setLanguage('en');
+                    $tsHeaderText->addTranslation($tHeaderText);
+                    $alert->setHeaderText($tsHeaderText);
+                }
+                if ($current_alert['description'] != '') {
+                    $tsDescriptionText = new transit_realtime\TranslatedString();
+                    $tDescriptionText = new transit_realtime\TranslatedString\Translation();
+                    $tDescriptionText->setText(trim($current_alert['description']));
+                    $tDescriptionText->setLanguage('en');
+                    $tsDescriptionText->addTranslation($tDescriptionText);
+                    $alert->setDescriptionText($tsDescriptionText);
+                }
+                $fe->setAlert($alert);
+                if ($affectsFilteredEntities) {
+                    $fm->addEntity($fe);
+                }
+            }
+            if ($informed_count > 0) {
+                return $fm;
+            } else {
+                return null;
+            }
+        } else
+            return null;
+    }
+
+    function getServiceAlertsAsArray($filter_class = '', $filter_id = '') {
+
+        $alerts = getServiceAlerts($filter_class, $filter_id);
+        if ($alerts != null) {
+            $codec = new DrSlump\Protobuf\Codec\PhpArray();
+
+            return $codec->encode($alerts);
+        } else {
+            return null;
+        }
+    }
+
+    function getServiceAlertsAsBinary($filter_class = '', $filter_id = '') {
+        $codec = new DrSlump\Protobuf\Codec\Binary();
+        return $codec->encode(getServiceAlerts($filter_class, $filter_id));
+    }
+
+    function getServiceAlertsAsJSON($filter_class = '', $filter_id = '') {
+        $codec = new DrSlump\Protobuf\Codec\Json();
+        return $codec->encode(getServiceAlerts($filter_class, $filter_id));
+    }
+
+    function getServiceAlertsByClass() {
+        $return = Array();
+        $alerts = getServiceAlertsAsArray('', '');
+        foreach ($alerts['entities'] as $entity) {
+            foreach ($entity['informed'] as $informed) {
+                foreach ($informed as $key => $value) {
+                    if (strpos('_id', $key) > 0) {
+                        $parts = explode($key);
+                        $class = $parts[0];
+                        $id = $value;
+                    }
+                }
+                $return[$class][$id][] = $entity;
+            }
+        }
+    }
+
+    function getTripUpdates($filter_class = '', $filter_id = '') {
+        $fm = new transit_realtime\FeedMessage();
+        $fh = new transit_realtime\FeedHeader();
+        $fh->setGtfsRealtimeVersion(1);
+        $fh->setTimestamp(time());
+        $fm->setHeader($fh);
+        foreach (getCurrentAlerts() as $alert) {
+            $informedEntities = getInformedAlerts($alert['id'], $_REQUEST['filter_class'], $_REQUEST['filter_id']);
+            $stops = Array();
+            $routestrips = Array();
+            if (sizeof($informedEntities) > 0) {
+                if ($informedEntity['informed_class'] == 'stop' && $informed['x-action'] == 'remove') {
+                    $stops[] = $informedEntity['informed_id'];
+                }
+                if (($informedEntity['informed_class'] == 'route' || $informedEntity['informed_class'] == 'trip') && $informed['x-action'] == 'patch') {
+                    $routestrips[] = Array('id' => $informedEntity['informed_id'],
+                        'type' => $informedEntity['informed_class']);
+                }
+            }
+            foreach ($routestrips as $routetrip) {
+                $fe = new transit_realtime\FeedEntity();
+                $fe->setId($alert['id'] . $routetrip['id']);
+                $fe->setIsDeleted(false);
+                $tu = new transit_realtime\TripUpdate();
+                $td = new transit_realtime\TripDescriptor();
+                if ($routetrip['type'] == 'route') {
+                    $td->setRouteId($routetrip['id']);
+                } else if ($routetrip['type'] == 'trip') {
+                    $td->setTripId($routetrip['id']);
+                }
+                $tu->setTrip($td);
+                foreach ($stops as $stop) {
+                    $stu = new transit_realtime\TripUpdate\StopTimeUpdate();
+                    $stu->setStopId($stop);
+                    $stu->setScheduleRelationship(transit_realtime\TripUpdate\StopTimeUpdate\ScheduleRelationship::SKIPPED);
+                    $tu->addStopTimeUpdate($stu);
+                }
+                $fe->setTripUpdate($tu);
+                $fm->addEntity($fe);
+            }
+        }
+        return $fm;
+    }
+
+    function getTripUpdatesAsArray($filter_class = '', $filter_id = '') {
+        $codec = new DrSlump\Protobuf\Codec\PhpArray();
+        return $codec->encode(getTripUpdates($filter_class, $filter_id));
+    }
+
+    function getTripUpdatesAsBinary($filter_class = '', $filter_id = '') {
+        $codec = new DrSlump\Protobuf\Codec\Binary();
+        return $codec->encode(getTripUpdates($filter_class, $filter_id));
+    }
+
+    function getTripUpdatesAsJSON($filter_class = '', $filter_id = '') {
+        $codec = new DrSlump\Protobuf\Codec\Json();
+        return $codec->encode(getTripUpdates($filter_class, $filter_id));
+    }
+
+}
+