Thursday, December 4, 2008

Using command line to debug your Web Service

You can actually run your PHP Web Service on the command line. One may wonder what the use of doing that ?

The main use case is that, you can test your service, without having to write a client. It is specially useful, if your are following the code first approach.  You can find the code for actually doing this in one of the WSF/PHP samples. It is in fact the simplest sample of all. The echo_service.php.

Lets have a look at how this becomes possible.

 WSService->reply() function takes an optional string argument . 

1. You can pass the actual XML string expected from the client to the reply function. Then, the service can be executed on the command line to see the actual executed output from an operation.

However, this would work only in cases where you using SOAP Body dispatching or WS-Addressing.

In SOAP Body dispatching case, the XML qualified name of the child element of soap body is used to identify the operation which should be invoked.

In case of WS-Addressing, the addressing action header is used.

2. Lets look at a code sample on implementing this.  This is the echo_service.php sample that comes with WSF/PHP

<?php

$requestPayloadString = <<<XML
<soapenv:Envelope xmlns:soapenv="
http://www.w3.org/2003/05/soap-envelope">
   <soapenv:Header/>
   <soapenv:Body>
     <ns1:echoString xmlns:ns1="
http://wso2.org/wsfphp/samples">
         <text>Hello World!</text>
     </ns1:echoString>
    </soapenv:Body>
</soapenv:Envelope>
XML;

function echoFunction($inMessage) {

    $outMessage = new WSMessage($inMessage->str);

    return $outMessage;
}

$operations = array("echoString" => "echoFunction");

$service = new WSService(array("operations" => $operations));
$service->reply($requestPayloadString);

?>

I have highlighted the important code segments. Note how the Expected soap envelope string is passed to the reply() function as an argument.

3. Now you can execute this service on the command line and get the result.

php echo_service.php

Now you should see the expected output soap envelope after invoking the echoString operation.

4. You can also generate the WSDL for the service on the command line as well. Simply set the reply function argument string to "wsdl" or "wsdl2".

$service->reply("wsdl");

5. Now you can re execute the service and get the wsdl for the service on the command line.

php echo_service.php

This is a very useful feature for debugging your hand coded services  :).

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