POST To Create

Tip

In this course we're using Symfony 2, but starting in episode 4, we use Symfony 3. If you'd like to see the finished code for this tutorial in Symfony 3, download the code from episode 4 and check out the start directory!

Well hey guys! I've wanted to write this series for years, and now that it's here, I'm so pumped! That's because even though building an API can be really tough, the system we're about to build feels simple, and really a bit beautiful.

We have another REST series on the site where we build the API in Silex and learn the short list of REST concepts like resources, representations, what status codes to return, what headers to set, how to format your JSON and a few other buzzwords like hypermedia, HATEOAS and of course, don't forget about our favorite: idempotency.

But in this series, I'll assume you have a basic grasp of this stuff and we'll get straight to work. If you're confused by a term, head back to that series to fill in any gaps.

The Project

Ok, I've got the "start" directory for the project downloaded, I've configured parameters.yml and I've already run composer install. So let's launch the built-in web server:

php app/console server:start

Hey, it's Code Battles! This is the same awesome project we built in Silex for the other REST series. It already has a slick web interface - so we're going to build the API. To make sure we can login, let's create the database and load the fixtures:

php app/console doctrine:database:create
php app/console doctrine:schema:create
php app/console doctrine:fixtures:load

Now login with a fixtures user: weaverryan and the very secure password foo.

The Code Battles Web Interface

To understand the API we're going to build, let me give you a quick 60-second tour. And please keep your hands and arms inside the project at all times.

The first resource is a programmer, and we start by creating one. Give it a name, a clever tag line, choose one of the avatars and compile! Next, a programmer has energy, and you can change that by powering them up. Sometimes good things happen that give you power, sometimes bad things happen -- like a case of the Mondays.

With some power, you can start a battle. These are projects, and projects are the second resource. And when you select one, it creates our third resource: a battle. Our programmer killed it! Each battle is between one programmer resource and one project resource. On the homepage, you can see a list of all the battles our programmer has bravely fought.

POST to /api/programmers

So where do we start with the API? Well, other than logging in - which we'll talk about later - the first thing we do on the web is create the programmer. That's where we should start. Building an API is no different than building for the web: you need to step back and think about your user-flow and build things piece-by-piece in that order.

Open up app/config/routing.yml. I'm loading annotation routes from a Controller/Web sub-directory. I put all my web stuff there because now I can create an Api directory right next it and keep things organized.

In routing.yml, I'll keep two separate route imports: one for Web/ and I'll add a new one for Api/. Trust me - this will come in handy later:

            
            8 lines
            
            app/config/routing.yml
        
            app_web:
        
                resource: "@AppBundle/Controller/Web"
        
                type:     annotation
        
            app_api:
        
                resource: "@AppBundle/Controller/Api"
        
                type:     annotation

Now create the new ProgrammerController - and make it extend Symfony's Controller like normal:

            
            21 lines
            
            src/AppBundle/Controller/Api/ProgrammerController.php
        
            <?php
        
            namespace AppBundle\Controller\Api;
        
            use Symfony\Bundle\FrameworkBundle\Controller\Controller;
        
                                                    ... lines 6 - 9
                            
            class ProgrammerController extends Controller
        
            {
        
                                                    ... lines 12 - 19
                            
            }

Our first endpoint will be for creating Programmers, so let's start with public function newAction(). Above it, setup the @Route annotation with the URL /api/programmers. Let's also make it only respond to POST requests:

            
            21 lines
            
            src/AppBundle/Controller/Api/ProgrammerController.php
        
                                                    ... lines 1 - 4
                            
            use Symfony\Bundle\FrameworkBundle\Controller\Controller;
        
            use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
        
            use Sensio\Bundle\FrameworkExtraBundle\Configuration\Method;
        
                                                    ... lines 8 - 9
                            
            class ProgrammerController extends Controller
        
            {
        
                /**
        
                 * @Route("/api/programmers")
        
                 * @Method("POST")
        
                 */
        
                public function newAction()
        
                {
        
                                                    ... line 18
                            
                }
        
            }

URL Structures and HTTP Methods

Ok, we just made 2 interesting architectural decisions:

First, we're going to start all our API URI's with /api. That's opinionated, and RESTfully speaking, it's wrong. REST says that if we want to return an HTML or JSON representation of a programmer resource, we should have just one URI - like /programmers/HappyCoderCat. This one URI should be able to return both formats based on a header the client sends.

If you want to do this, awesome - go for it! But it's not easy to do, and I'm not sure it's worth it. That's why we've separated the Web and Api stuff into different controllers and URIs. Now we can focus just on getting our API right.

The second architectural decision we made was to create a new resource by sending a POST request to that resource's collection URI - so /api/programmers. If you're curious why, watch our other screencast and learn about idempotency. And, in REST, you can make your URLs look however you want. But in practice, we're going to use a very consistent pattern. Because even though you can make your URLs super weird you probably shouldn't.

"Testing" the POST Endpoint

We'll return a new Response from the controller: Let's do this!

            
            21 lines
            
            src/AppBundle/Controller/Api/ProgrammerController.php
        
                                                    ... lines 1 - 7
                            
            use Symfony\Component\HttpFoundation\Response;
        
                                                    ... lines 9 - 11
                            
                /**
        
                 * @Route("/api/programmers")
        
                 * @Method("POST")
        
                 */
        
                public function newAction()
        
                {
        
                    return new Response('Let\'s do this!');
        
                }
        
                                                    ... lines 20 - 21

Ok, so the easy days of just refreshing our browser to try this out are gone: we can't POST here directly in a browser. Now, a lot of people use Postman or something like it to test their API. And while it's great, I think there's a better way.

For now, create a new file - testing.php - right at the root of the project. Inside, require Composer's autoloader:

            
            16 lines
            
            testing.php
        
            <?php
        
            require __DIR__.'/vendor/autoload.php';
        
                                                    ... lines 4 - 16

We're going to use the Guzzle library to hit our new endpoint and make sure it's working. I already installed it into the project - so go directly to $client = new Client([]) and pass it some configuration:

            
            16 lines
            
            testing.php
        
                                                    ... lines 1 - 4
                            
            $client = new \GuzzleHttp\Client([
        
                'base_url' => 'http://localhost:8000',
        
                'defaults' => [
        
                    'exceptions' => false
        
                ]
        
            ]);
        
                                                    ... lines 11 - 16

Tip

We are using Guzzle 5. If you are using Guzzle 6 (or newer), there are (at least) 2 important changes:

The base_url option has changed to base_uri
The defaults.exceptions option has changed to http_errors
echo'ing a response object doesn't work anymore. Instead, use echo $response->getBody();

The first is base_url set to localhost:8000. Next, pass it a defaults key - these are options that'll be passed, by default, to each request. Set one option - exceptions - to false. Normally, if our server returns a 400 or 500 status code, Guzzle blows up with an Exception. This makes it act normal - it'll return a Response always. Trust me, that's nice!

Now make the request - $response = $client->post('/api/programmers'). Echo the $response - it's an object, but has a really pretty __toString method on it:

            
            16 lines
            
            testing.php
        
                                                    ... lines 1 - 11
                            
            $response = $client->post('/api/programmers');
        
            echo $response;
        
            echo "\n\n";

Try it by hitting this file from the command line:

php testing.php

Ok, let's fill in the guts and make this work!

What PHP libraries does this tutorial use?

// composer.json
{
    "require": {
        "php": ">=5.3.3",
        "symfony/symfony": "2.6.*", // v2.6.11
        "doctrine/orm": "~2.2,>=2.2.3,<2.5", // v2.4.7
        "doctrine/dbal": "<2.5", // v2.4.4
        "doctrine/doctrine-bundle": "~1.2", // v1.4.0
        "twig/extensions": "~1.0", // v1.2.0
        "symfony/assetic-bundle": "~2.3", // v2.6.1
        "symfony/swiftmailer-bundle": "~2.3", // v2.3.8
        "symfony/monolog-bundle": "~2.4", // v2.7.1
        "sensio/distribution-bundle": "~3.0,>=3.0.12", // v3.0.21
        "sensio/framework-extra-bundle": "~3.0,>=3.0.2", // v3.0.7
        "incenteev/composer-parameter-handler": "~2.0", // v2.1.0
        "hautelook/alice-bundle": "0.2.*", // 0.2
        "jms/serializer-bundle": "0.13.*" // 0.13.0
    },
    "require-dev": {
        "sensio/generator-bundle": "~2.3", // v2.5.3
        "behat/behat": "~3.0", // v3.0.15
        "behat/mink-extension": "~2.0.1", // v2.0.1
        "behat/mink-goutte-driver": "~1.1.0", // v1.1.0
        "behat/mink-selenium2-driver": "~1.2.0", // v1.2.0
        "phpunit/phpunit": "~4.6.0" // 4.6.4
    }
}

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Symfony RESTful API: Course 1