IoT Platform:Connect a client to IoT Platform by using the SDK for PHP

Download the SDK

The sample code is written based on the Stomp PHP library and allows you to connect a Stomp PHP client to IoT Platform over Simple Text Oriented Message Protocol (STOMP). To download a Stomp PHP client and view the instructions, visit Stomp PHP.

For information about the PHP versions that Stomp SDK for PHP supports, see the declaration of the require parameter in the composer.json file of Stomp SDK for PHP.

In Stomp PHP versions earlier than 5.0.0, the SDK may fail to reconnect to IoT Platform after the SDK is disconnected. We recommend that you download Stomp PHP 5.0.0 or later. For more information, see Issues.

In the PHP project directory, run the following command to download the SDK of Stomp PHP 5.0.0:

composer require stomp-php/stomp-php 5.0.0

Sample code

<?php
require __DIR__ . '/vendor/autoload.php';
use Stomp\Client;
use Stomp\Network\Observer\Exception\HeartbeatException;
use Stomp\Network\Observer\ServerAliveObserver;
use Stomp\StatefulStomp;

// For more information about the parameters, see the "Connect an AMQP client to IoT Platform" topic. 
// If you hard-code the AccessKey pair in the project code, the AccessKey pair may be disclosed if the project code is leaked. In this case, the resources within your account become insecure. The following sample code provides an example on how to obtain the AccessKey pair from environment variables. This example is for reference only.
$accessKey = getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
$accessSecret = getenv('ALIBABA_CLOUD_ACCESS_KEY_SECRET');
$consumerGroupId = "${YourConsumerGroupId}";
$clientId = "${YourClientId}";
// iotInstanceId: The ID of the IoT Platform instance. 
$iotInstanceId = "${YourIotInstanceId}";
$timeStamp = round(microtime(true) * 1000);
// The signature algorithm. Valid values: hmacmd5, hmacsha1, and hmacsha256. 
$signMethod = "hmacsha1";
// The structure of the userName parameter. For more information, see the "Connect an AMQP client to IoT Platform" topic. 
// If you want to transmit messages in the binary format, specify encode=base64 in the userName parameter. Before IoT Platform sends these messages, IoT Platform encodes these messages by using the Base64 algorithm. For more information, see the "Messages in the binary format" section of this topic. 
$userName = $clientId . "|authMode=aksign"
            . ",signMethod=" . $signMethod
            . ",timestamp=" . $timeStamp
            . ",authId=" . $accessKey
            . ",iotInstanceId=" . $iotInstanceId
            . ",consumerGroupId=" . $consumerGroupId
            . "|";
$signContent = "authId=" . $accessKey . "&timestamp=" . $timeStamp;
// Calculate a signature. For more information about how to construct the password, see the "Connect an AMQP client to IoT Platform" topic. 
$password = base64_encode(hash_hmac("sha1", $signContent, $accessSecret, $raw_output = TRUE));
// The endpoint. For more information, see the "Connect an AMQP client to IoT Platform" topic. 
$client = new Client('ssl://${YourHost}:61614');
$sslContext = ['ssl' => ['verify_peer' => true, 'verify_peer_name' => false], ];
$client->getConnection()->setContext($sslContext);

// Configure a listener to monitor the status of the connection between the client and IoT Platform. 
$observer = new ServerAliveObserver();
$client->getConnection()->getObservers()->addObserver($observer);
// The heartbeat setting. This setting enables IoT Platform to send a heartbeat packet every 30 seconds. 
$client->setHeartbeat(0, 30000);
$client->setLogin($userName, $password);
try {
    $client->connect();
}
catch(StompException $e) {
    echo "failed to connect to server, msg:" . $e->getMessage() , PHP_EOL;
}
// Run the following code if no exceptions occur: 
$stomp = new StatefulStomp($client);
$stomp->subscribe('/topic/#');
echo "connect success";

while (true) {
    try {

        // Check the connection status.
        if (!$client->isConnected()) {
            echo "connection not exists, will reconnect after 10s.", PHP_EOL;
            sleep(10);
            $client->connect();
            $stomp->subscribe('/topic/#');
            echo "connect success", PHP_EOL;
        }

        // Specify the business logic to process messages. 
        echo $stomp->read();
    }
    catch(HeartbeatException $e) {
        echo 'The server failed to send us heartbeats within the defined interval.', PHP_EOL;
        $stomp->getClient()->disconnect();
    } catch(Exception $e) {
        echo 'process message occurs error: '. $e->getMessage() , PHP_EOL;
        $stomp->getClient()->disconnect();
    }
}   

You can configure the parameters in the preceding code based on the parameter description in the following table. For more information about other parameters, see Connect an AMQP client to IoT Platform.

Sample results

• If information similar to the following output is displayed, the AMQP client is connected to IoT Platform and can receive messages.

• If information similar to the following output is displayed, the AMQP client fails to connect to IoT Platform.

  You can check the code or network environment based on logs, resolve the issue, and then run the code again.

  

Messages in the binary format

If you want to transmit messages in the binary format, use the Base64 algorithm to encode the messages. If you do not use the Base64 algorithm to encode the messages, the messages may be truncated because STOMP is a text-based protocol.

The following code shows how to specify encode=base64 in the userName parameter. This setting enables IoT Platform to encode messages by using the Base64 algorithm before IoT Platform sends the messages.

$userName = $clientId . "|authMode=aksign"
                . ",signMethod=" . $signMethod
                . ",timestamp=" . $timeStamp
                . ",authId=" . $accessKey
                . ",iotInstanceId=" . $iotInstanceId
                . ",consumerGroupId=" . $consumerGroupId
                . ",encode=base64" . "|";

References

For more information about the error codes that are related to the server-side subscription feature, see the Error codes that are related to messages section of the "IoT Platform logs" topic.