JsonRPC PHP Client and Server

A simple Json-RPC client/server that just works.

Features

• JSON-RPC 2.0 only
• The server support batch requests and notifications
• Authentication and IP based client restrictions
• Custom Middleware
• Fully unit tested
• Requirements: PHP >= 5.3.4
• License: MIT

Author

Frédéric Guillot

Installation with Composer

composer require fguillot/json-rpc @stable

Examples

Server

Callback binding:

<?php

use JsonRPC\Server;

$server = new Server();
$server->getProcedureHandler()
    ->withCallback('addition', function ($a, $b) {
        return $a + $b;
    })
    ->withCallback('random', function ($start, $end) {
        return mt_rand($start, $end);
    })
;

echo $server->execute();

Callback binding from array:

<?php

use JsonRPC\Server;

$callbacks = array(
    'getA' => function() { return 'A'; },
    'getB' => function() { return 'B'; },
    'getC' => function() { return 'C'; }
);

$server = new Server();
$server->getProcedureHandler()->withCallbackArray($callbacks);

echo $server->execute();

Class/Method binding:

<?php

use JsonRPC\Server;

class Api
{
    public function doSomething($arg1, $arg2 = 3)
    {
        return $arg1 + $arg2;
    }
}

$server = new Server();
$procedureHandler = $server->getProcedureHandler();

// Bind the method Api::doSomething() to the procedure myProcedure
$procedureHandler->withClassAndMethod('myProcedure', 'Api', 'doSomething');

// Use a class instance instead of the class name
$procedureHandler->withClassAndMethod('mySecondProcedure', new Api, 'doSomething');

// The procedure and the method are the same
$procedureHandler->withClassAndMethod('doSomething', 'Api');

// Attach the class, the client will be able to call directly Api::doSomething()
$procedureHandler->withObject(new Api());

echo $server->execute();

Class/Method binding from array:

<?php

use JsonRPC\Server;

class MathApi
{
    public function addition($arg1, $arg2)
    {
        return $arg1 + $arg2;
    }

    public function subtraction($arg1, $arg2)
    {
        return $arg1 - $arg2;
    }

    public function multiplication($arg1, $arg2)
    {
        return $arg1 * $arg2;
    }

    public function division($arg1, $arg2)
    {
        return $arg1 / $arg2;
    }
}

$callbacks = array(
    'addition'       => array( 'MathApi', addition ),
    'subtraction'    => array( 'MathApi', subtraction ),
    'multiplication' => array( 'MathApi', multiplication ),
    'division'       => array( 'MathApi', division )
);

$server = new Server();
$server->getProcedureHandler()->withClassAndMethodArray($callbacks);

echo $server->execute();

Server Middleware:

Middleware might be used to authenticate and authorize the client. They are executed before each procedure.

<?php

use JsonRPC\Server;
use JsonRPC\MiddlewareInterface;
use JsonRPC\Exception\AuthenticationFailureException;

class Api
{
    public function doSomething($arg1, $arg2 = 3)
    {
        return $arg1 + $arg2;
    }
}

class MyMiddleware implements MiddlewareInterface
{
    public function execute($username, $password, $procedureName)
    {
        if ($username !== 'foobar') {
            throw new AuthenticationFailureException('Wrong credentials!');
        }
    }
}

$server = new Server();
$server->getMiddlewareHandler()->withMiddleware(new MyMiddleware());
$server->getProcedureHandler()->withObject(new Api());
echo $server->execute();

You can raise a AuthenticationFailureException when the API credentials are wrong or a AccessDeniedException when the user is not allowed to access to the procedure.

Client

Example with positional parameters:

<?php

use JsonRPC\Client;

$client = new Client('http://localhost/server.php');
$result = $client->execute('addition', [3, 5]);

Example with named arguments:

<?php

use JsonRPC\Client;

$client = new Client('http://localhost/server.php');
$result = $client->execute('random', ['end' => 10, 'start' => 1]);

Arguments are called in the right order.

Examples with the magic method __call():

<?php

use JsonRPC\Client;

$client = new Client('http://localhost/server.php');
$result = $client->random(50, 100);

The example above use positional arguments for the request and this one use named arguments:

$result = $client->random(['end' => 10, 'start' => 1]);

Client batch requests

Call several procedures in a single HTTP request:

<?php

use JsonRPC\Client;

$client = new Client('http://localhost/server.php');

$results = $client->batch()
                  ->foo(['arg1' => 'bar'])
                  ->random(1, 100)
                  ->add(4, 3)
                  ->execute('add', [2, 5])
                  ->send();

print_r($results);

All results are stored at the same position of the call.

Client exceptions

Client exceptions are normally thrown when an error is returned by the server. You can change this behaviour by using the $returnException argument which causes exceptions to be returned. This can be extremely useful when executing the batch request.

• BadFunctionCallException: Procedure not found on the server
• InvalidArgumentException: Wrong procedure arguments
• JsonRPC\Exception\AccessDeniedException: Access denied
• JsonRPC\Exception\ConnectionFailureException: Connection failure
• JsonRPC\Exception\ServerErrorException: Internal server error

Enable client debugging

You can enable the debug mode to see the JSON request and response:

<?php

use JsonRPC\Client;

$client = new Client('http://localhost/server.php');
$client->getHttpClient()->withDebug();

The debug output is sent to the PHP system logger. You can configure the log destination in your php.ini.

Output example:

==> Request:
{
    "jsonrpc": "2.0",
    "method": "removeCategory",
    "id": 486782327,
    "params": [
        1
    ]
}
==> Response:
{
    "jsonrpc": "2.0",
    "id": 486782327,
    "result": true
}

IP based client restrictions

The server can allow only some IP addresses:

<?php

use JsonRPC\Server;

$server = new Server;

// IP client restrictions
$server->allowHosts(['192.168.0.1', '127.0.0.1']);

[...]

// Return the response to the client
echo $server->execute();

If the client is blocked, you got a 403 Forbidden HTTP response.

HTTP Basic Authentication

If you use HTTPS, you can allow client by using a username/password.

<?php

use JsonRPC\Server;

$server = new Server;

// List of users to allow
$server->authentication(['user1' => 'password1', 'user2' => 'password2']);

[...]

// Return the response to the client
echo $server->execute();

On the client, set credentials like that:

<?php

use JsonRPC\Client;

$client = new Client('http://localhost/server.php');
$client->getHttpClient()
    ->withUsername('Foo')
    ->withPassword('Bar');

If the authentication failed, the client throw a RuntimeException.

Using an alternative authentication header:

use JsonRPC\Server;

$server = new Server();
$server->setAuthenticationHeader('X-Authentication');
$server->authentication(['myusername' => 'mypassword']);

The example above will use the HTTP header X-Authentication instead of the standard Authorization: Basic [BASE64_CREDENTIALS]. The username/password values need be encoded in base64: base64_encode('username:password').

Local Exceptions

By default, the server will relay all exceptions to the client. If you would like to relay only some of them, use the method Server::withLocalException($exception):

<?php

use JsonRPC\Server;
class MyException1 extends Exception {};
class MyException2 extends Exception {};

$server = new Server();

// Exceptions that should NOT be relayed to the client, if they occurs
$server
    ->withLocalException('MyException1')
    ->withLocalException('MyException2')
;

[...]

echo $server->execute();

Callback before client request

You can use a callback to change the HTTP headers or the URL before to make the request to the server.

Example:

<?php

$client = new Client();
$client->getHttpClient()->withBeforeRequestCallback(function(HttpClient $client, $payload) {
    $client->withHeaders(array('Content-Length: '.strlen($payload)));
});

$client->myProcedure(123);