WellRESTed

WellRESTed provides classes to help you create RESTful APIs and work with HTTP requests and responses.

Requirements

• PHP 5.3
• Composer for autoloading
• PHP cURL for making requests

Install

Add an entry for "pjdietz/wellrested" to your composer.json file's require property. If you are not already using Composer, create a file in your project called composer.json with the following content:

{
    "require": {
        "pjdietz/wellrested": "1.*"
    }
}

Use Composer to download and install WellRESTed. Run these commands from the directory containing the composer.json file.

$ curl -s https://getcomposer.org/installer | php
$ php composer.phar install

You can now use WellRESTed by including the autoload.php file generated by Composer. (vendor/autoload.php)

Examples

Routing

WellRESTed's primary goal is to facilitate mapping of URIs to classes that will provide or accept representations. To do this, create a Router instance and load it up with some Routes. Each Route is simply a mapping of a URI pattern to a classname. The classname represents the Handler class which the router will dispatch at the time it recieves a request for the given URI. The handlers are never loaded until they are needed.

Here's an example of a Router that will handle two URIs:

// Build the router.
$myRouter = new Router();
$myRouter->addRoute(Route::newFromUriTemplate('/things/', 'ThingCollectionHandler'));
$myRouter->addRoute(Route::newFromUriTemplate('/things/{id}', 'ThingItemHandler'));

// Determine and output the response.
$response = $router->getResponse();
$response->respond();

When you create your Handler subclass, you will provide a method for each HTTP verb you would like the endpoint to support. For example, if /things/ should support GET, you would override the get() method. For POST, post(), etc.

If your endpoint should reject particular verbs, no worries. The Handler base class defines the default verb-handling methods to respond with a 405 Method Not Allowed status.

Here's a simple Handler that matches the first endpoint, /things/.

class ThingCollectionHandler extends \pjdietz\WellRESTed\Handler
{
    protected function get()
    {
        // Read some things from the database, cache, whatever.
        // ...

        // Set the values for the instance's reponse member. This what the
        // Router will eventually use to output a response to the client.
        $this->response->statusCode = 200;
        $this->response->setHeader('Content-Type', 'application/json');
        $this->response->body = json_encode($data);
    }

    protected function post()
    {
        // Read from the instance's request member and store a new Thing.
        // ...

        // Build a reponse to send to the client.
        $this->response->statusCode = 201;
        $this->response->body = 'You added a thing!';
    }
}

This Handler works with the second endpoint, /things/{id}. The pattern for this endpoing has a variable in it ({id}). The Handler can access path variables through its args member, which is an associative array of variable from the URI.

class ThingItemHandler extends \pjdietz\WellRESTed\Handler
{
    protected function get()
    {
        // Lookup a Thing based on $this->args['id']
        // ...

        if ($thing) {
            // The Thing exists! Let's output a representation.
            $this->response->statusCode = 200;
            $this->response->setHeader('Content-Type', 'application/json');
            $this->response->body = json_encode($thing);
        } else {
            // The ID did not match anything.
            $this->response->statusCode = 404;
            $this->response->setHeader('Content-Type', 'text/plain');
            $this->response->body = 'No thing with id ' . $this->args['id'];
        }
    }
}

Requests and Responses

You've already seen a Response in use in the examples above. You can also use Responses outside of Handlers. Let's take a look at creating a new Response, setting a headers, supplying the body, and outputting.

$resp = new \pjdietz\WellRESTed\Response();
$resp->statusCode = 200;
$resp->setHeader('Content-type', 'text/plain');
$resp->body = 'Hello world!';
$resp->respond();
exit;

The Request class goes hand-in-hand with the Response class. Again, this is used in the Handler class to read the information from the request being handled. From outside the context of a Handler, you can also use the Request class to read info for the request sent to the server.

$rqst = \pjdietz\WellRESTed\Request::getRequest();

if ($rqst->method === 'PUT') {
    $obj = json_decode($rqst->body);
    // Do something with the JSON sent as the message body.
}

The Request class can also make a request to another server and provide the response as a Respones object. (This feature requires PHP cURL.)

// Prepare a request.
$rqst = new \pjdietz\WellRESTed\Request();
$rqst->uri = 'http://my.api.local/resources/';
$rqst->method = 'POST';
$rqst->body = json_encode($newResource);

// Make the request.
$resp = $rqst->request();

// Read the response.
if ($resp->statusCode === 201) {
    // The new resource was created.
    $newResource = json_decode($resp->body);
}

More Examples

For more examples, see the project pjdietz/wellrested-samples.

Copyright and License

Copyright © 2013 by PJ Dietz Licensed under the MIT license