Introduction about the XML_RPC2 "cached client side" usage

Thanks to PHP5 and PEAR/Cache_Lite, it's really easy to do XMLRPC "cached client" requests with XML_RPC2. The usage is really straightforward.

First, you include 'XML/RPC2/CachedClient.php' file (only this one).

require_once 'XML/RPC2/CachedClient.php';

Second, you make an assocative arrays of options to tune XML_RPC2 (prefix, proxy, manual backend choice...).

$options = array(
    'prefix' => 'package.',
    'cacheOptions' => array(
        'cacheDir' => '/tmp/',
        'lifetime' => 3600
    )
);

Third, you make a XML_RPC2_CachedClient object with the server URL and the with the options array.

$client = XML_RPC2_CachedClient::create('http://pear.php.net/xmlrpc.php', $options);

Then, you send your request by calling the server method as it was a local method of the $client object.

$result = $client->info('XML_RPC2');

Of course, to catch server errors, you have to add a few lines around you client call like for example :

try {
    $result = $client->info('XML_RPC2'); 
    print_r($result);
} catch (XML_RPC2_FaultException $e) {
    // The XMLRPC server returns a XMLRPC error
    die('Exception #' . $result->getFaultCode() . ' : ' . $e->getFaultString());
} catch (Exception $e) {  
    // Other errors (HTTP or networking problems...)
    die('Exception : ' . $e->getMessage());
}

The options array

This array is completely optional but really usefull. The following keys are available :

Making the XML_RPC2_CachedClient object

It's really easy to make the XML_RPC2_CachedClient object. Use the following syntax :

// $XMLRPCServerURL is a string : 'http://pear.php.net/xmlrpc.php' (for example)
// $options is an optional array : see previous section for more informations
$client = XML_RPC2_CachedClient::create($XMLRPCServerURL, $options);

Call the XMLRPC exported method

See "non cached client side" documentation, there is no difference.

The caching process is completly embedded and automatic. If a cache is available, result will be get from cache and no HTTP request will be sent. If there is no cache available for this particular call (method name and arguments), the classical XMLRPC communication will be used (and the result will be stored into a cache file for the next use).