JSON-RPC 1.0 + 2.0 Handler

The class Vectorface\SnappyRouter\Handler\JsonRpcHandler provides a means of calling class methods via the JSON-RPC protocol. Version 1.0 and 2.0 of the protocol should both be fully supported.

Some items of interest about this implementation:

• Supports batch calls; Many calls in a single request.
• Notification calls; Drops responses without a request id.
• Handles both parameter arrays, and named parameters.
• Transparently handles both the JSON-RPC 1.0 and 2.0 spec.
• JSON-RPC 1.0 class hinting is delibrately not supported.

Why JSON-RPC?

JSON-RPC allows calling server-side methods on the client side nearly transparently. The only limitations are generally limitations of JSON serialization; PHP associative arrays become untyped JSON objects.

Put differently, a remote procedure call can be abstracted out to look almost identical to a local method call, making it very easy to integrate server-side calls into client-side or remote code.

API clients can also be simpler too because the local and remote method signatures can be the same. There is no need to map URLs and/or parameters as in REST APIs.

For example, one could expose the following class on the server:

<?php

namespace Vendor\MyNamespace\RpcServices;

class Adder
{
    public function add($arg1, $arg2)
    {
        return $arg1 + $arg2;
    }
}

The class Adder can be called locally as:

$adder = new Vendor\MyNamespace\RpcServices\Adder();
$adder->add(1, 1); // 2!

Or it could be called remotely:

$adder = new MyJsonRpcClient("http://.../Adder"); // Any JSON-RPC client.
$adder->add(1, 1); // 2!

Usage

To expose the example Adder class listed in the previous section, configure a router instance as follows:

<?php

use Vectorface\SnappyRouter\Config\Config;

$config = new Config(array(
    Config::KEY_HANDLERS => array(
        'JsonRpcHandler' => array(
            Config::KEY_CLASS => 'Vectorface\\SnappyRouter\\Handler\\JsonRpcHandler',
            Config::KEY_OPTIONS => array(
                Config::KEY_SERVICES => array(
                    'Adder' => 'Vendor\\MyNamespace\\RpcServices\\Adder' // Adder, as above
                ),
            )
        )
    )
));
$router = new Vectorface\SnappyRouter\SnappyRouter($config);
echo $router->handleRoute();

If the router is called with a URI ending in "Adder(.php)" and a valid JSON-RPC request POSTed for the method "add", the router will response with a JSON-RPC encoded response with the sum of the two arguments.