PHP Examples

There are two PHP libraries which can be used to access the data feeds:

• PECL Stomp package
• Stomp library

PECL Stomp

The PECL Stomp Package can be installed through the PECL command line tool; this is part of the PHP PEAR extensions package. Instructions for installing PEAR and PECL on different systems can be found by searching the web. Once PECL is installed, type pecl install stomp at the command line.

Documentation for the PECL Stomp package can be found on the PHP:Stomp Manual page.

Basic Network Rail Example

This example connects to the Network Rail data feed via STOMP, subscribes to the TRAIN_MVT_ALL_TOC topic, and sets up a loop listening for new frames. Unless the connection is lost, it would need to be killed from the command line. The example for National Rail data includes a brief method of limiting the frames.

<?php
// Network Rail Stomp Handler example by ian13
$server = "tcp://datafeeds.networkrail.co.uk:61618";
$user = "username";
$password = "password";
$channel = "TRAIN_MVT_ALL_TOC";
 
$con = new Stomp($server, $user, $password);
if (!$con) {
   die('Connection failed: ' . stomp_connect_error());
}
 
$con->subscribe("/topic/" . $channel);
 
while($con){
   if ($con->hasFrame()){
       $msg = $con->readFrame();
       foreach (json_decode($msg->body) as $event) {

         // do stuff with $event here

       }
       $con->ack($msg);
   }
}
 
die('Connection lost: ' . time());
?>

Basic National Rail Push Port Example

This example connects to the National Rail data feed via STOMP, subscribes to the GIVEN_QUEUE topic, and sets up a loop listening for new frames. It also is limited on the loop for a specific number of frames, which is particularly useful when testing. This can be changed using the number variable. If you want to look at the output, in the 'do stuff area', you can simply add in "print_r($event);". The function gzdecode is also only available from PHP 5.4.

<?php
// Network Rail Stomp Handler example by Joni Ellenby
$server = "tcp://datafeeds.nationalrail.co.uk:61613";
$user = "GIVEN_USER";
$password = "GIVEN_PASS";
$queue = "GIVEN_QUEUE";

$number = '20' ;
$i = '0' ;

 
$con = new Stomp($server, $user, $password);
if (!$con) {
   die('Connection failed: ' . stomp_connect_error());
}
 
$con->subscribe("/queue/" . $queue);
 
while($con && $i < $number){
   if ($con->hasFrame()){
       $msg = $con->readFrame();
       $event = gzdecode($msg->body)
       $i++ ;

         // do stuff with $event here

       $con->ack($msg);
   }
}
 
die('Connection lost: ' . time());
?>

Durable Subscriptions

The example above will only receive messages while it is connected to the STOMP server. By specifying a client-id header in the connection, and an activemq.subscriptionName header in the subscription, messages that were sent while the client was offline will be received upon connection.

// Specify a client-id header in the connection

$con = new Stomp($server, $user, $password, array('client-id' => 'somename'));
…
// Specify an activemq.subscriptionName header in the subscription
$con->subscribe("/topic/" . $channel, array('activemq.subscriptionName' => 'somename'));
…

Stomp library

An alternative Stomp client is available from Fuse Source. It has some minor issues, such as injecting spaces in the username/password, and sleeping on message retrieval.

A fixed version can be obtained from here or here.

require_once('Stomp.php');

$con = new Stomp('tcp://datafeeds.networkrail.co.uk:61618/'); $con->clientId = 'someclient'; $con->connect($username, $password);

$con->subscribe("/topic/TRAIN_MVT_ALL_TOC"); $msg = $con->readFrame();

if ($msg != null) {

 foreach (json_decode($msg->body) as $event) {
   // do stuff with $event here
 }
 $con->ack(msg);

}

$con->disconnect();