Mastering Route config Loading

Ok, you're a configuration pro: you know where services come from and how to configure them. Here's our question: where do routes come from? And can third party bundles give us more routes?

The answer is, no :(. Ah, I'm kidding - they totally can. In fact, find your terminal and run:

./bin/console debug:router

Surprise! There are a lot more than just the two routes that we've created. Where are these coming from?

Answer time: when Symfony loads the route list, it only loads one routing file. In the dev environment, it loads routing_dev.yml:

In all environments, it loads routing.yml:

Inside routing_dev.yml, we're importing additional routes from WebProfilerBundle and the TwigBundle:

That's why there are extra routes in debug:router. This also imports routing.yml at the bottom to load all the main routes:

You can really import anything you want: you're in complete control of what routes you import from a bundle. These files are usually XML, but that doesn't make any difference.

In the main routing.yml, there's yet another import:

We're out of control! This loads annotation routes from the controllers in our bundle.

Creating YAML Routes

But you can also create routes right inside YAML - a lot of people actually prefer this over annotations. The difference is purely preference: there's no performance impact to either.

Let's create a homepage route: use the key homepage - that's its name. Then add path set to just /:

Now, we need to point this route to a controller: the function that will render it. Doing this in yml is a bit more work. Add a defaults key and an _controller key below that. Set this to AppBundle:Main:homepage:

Yes yes, this looks totally weird - this is a Symfony-specific shortcut. It means that we will have a controller in AppBundle called MainController with a method named homepageAction().

In the Controller directory, create that new MainController class:

Next add public function homepageAction(). Make this class extend Symfony's base Controller so that we can access the render() function. Set it to render main/homepage.html.twig without passing any variables:

Create this real quick in app/Resources/views: new file, main/homepage.html.twig:

Templates basically always look the same: extend the base template - base.html.twig - and then override one or more of its blocks. Override block body: the block that holds the main content in base.html.twig.

Add some content to greet the aquanauts:

Done! Before trying this, head over to the terminal and run:

./bin/console debug:router

There it is! There are many ways to define a route, but the result is exactly the same. Refresh the browser. Thank you yml for that lovely brand new route.

Woh guys. This course was a serious step forward. In the next parts, we're going to start adding big features: like talking to a database, forms, security and more. And when we do, I've got some exciting news: because of your work here, it's all going to make sense. Let's keep going and get really productive with Symfony.