PHP SOAP Extension - Creating the Server (Page 5 of 8 )
Now it’s time to create our server.
First, we’ll implement the getQuote() function, which will be accessed as a service function by incoming request messages from the web. Next, we’ll create a SoapServer object and connect it with the service function using SoapServer::addFunction() method. As you will see, the SoapServer() constructor has only one parameter: the path of the WSDL document that describes the service.
Example 4 (server1. php)
<?php
$quotes = array(
"ibm" => 98.42
);
function getQuote($symbol) {
global $quotes;
return $quotes[$symbol];
}
ini_set("soap.wsdl_cache_enabled", "0"); // disabling WSDL cache
$server = new SoapServer("stockquote1.wsdl");
$server->addFunction("getQuote");
$server->handle();
The SoapServer can work without a WSDL document in much the same way that the SoapClient can, but there are no obvious benefits to be had from setting it up in this way. Were you to do so, you should ensure that the return values are special objects of the SoapParam and SoapVar classes (as in the first example).
Here is a client for accessing our own SOAP server. Nothing has changed from the previous example except the WSDL location. It assumes that “stockquote1.wsdl” is in the same directory as our SOAP server.
Example 5 (client3.php)
<?php
$client = new SoapClient("stockquote1.wsdl");
print($client->getQuote("ibm"));? >
What are the problem areas with our server and client?
To start with, they don’t handle errors. What happens when the server doesn’t recognize the requested symbol? The SOAP protocol specifies a special format of messages for reporting errors – SoapFault. To generate such messages the server should throw an exception using the SoapFault object. The first parameter to the SoapFault() constructor is a fault code string, and the second is a fault description string. The client should be written in such a way as to catch SoapFault exceptions.
Secondly, it would be better to encapsulate Web Service functionality in a PHP class. In this case we wouldn’t need to use global variables and add each SOAP method to the server individually; we could add an entire class, and all its methods would be accessible through SOAP.
Next: Example 6 >>
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