9. Using XML-RPC with PHP

Edd Dumbill has implemented XML-RPC for PHP. You can download it from the UsefulInc XML-RPC website.

To install the distribution, decompress it and copy xmlrpc.inc and xmlrpcs.inc into the same directory as your PHP scripts.

9.1. A PHP Client

The following script shows how to embed XML-RPC calls into a web page.

<html>
<head>
<title>XML-RPC PHP Demo</title>
</head>
<body>
<h1>XML-RPC PHP Demo</h1>
<?php
include 'xmlrpc.inc';
// Make an object to represent our server.
$server = new xmlrpc_client('/api/sample.php',
                            'xmlrpc-c.sourceforge.net', 80);
// Send a message to the server.
$message = new xmlrpcmsg('sample.sumAndDifference',
                         array(new xmlrpcval(5, 'int'),
                               new xmlrpcval(3, 'int')));
$result = $server->send($message);
// Process the response.
if (!$result) {
    print "<p>Could not connect to HTTP server.</p>";
} elseif ($result->faultCode()) {
    print "<p>XML-RPC Fault #" . $result->faultCode() . ": " .
        $result->faultString();
} else {
    $struct = $result->value();
    $sumval = $struct->structmem('sum');
    $sum = $sumval->scalarval();
    $differenceval = $struct->structmem('difference');
    $difference = $differenceval->scalarval();
    print "<p>Sum: " . htmlentities($sum) .
        ", Difference: " . htmlentities($difference) . "</p>";
}
?>
</body></html>

If your webserver doesn't run PHP scripts, see the PHP website for more information.

9.2. A PHP Server

The following script shows how to implement an XML-RPC server using PHP.

<?php
include 'xmlrpc.inc';
include 'xmlrpcs.inc';
function sumAndDifference ($params) {
    // Parse our parameters.
    $xval = $params->getParam(0);
    $x = $xval->scalarval();
    $yval = $params->getParam(1);
    $y = $yval->scalarval();
    // Build our response.
    $struct = array('sum' => new xmlrpcval($x + $y, 'int'),
                    'difference' => new xmlrpcval($x - $y, 'int'));
    return new xmlrpcresp(new xmlrpcval($struct, 'struct'));
}
// Declare our signature and provide some documentation.
// (The PHP server supports remote introspection. Nifty!)
$sumAndDifference_sig = array(array('struct', 'int', 'int'));
$sumAndDifference_doc = 'Add and subtract two numbers';
new xmlrpc_server(array('sample.sumAndDifference' =>
                        array('function' => 'sumAndDifference',
                              'signature' => $sumAndDifference_sig,
                              'docstring' => $sumAndDifference_doc)));
?>

You would normally invoke this as something like http://localhost/path/sumAndDifference.php.