Why does Laravel allow us to render views in routes?

Question

In the latest lecture at my University, my professor is returning the View template from the routes.

Route::get('/list', function() {
 return View::make('list'); 
}

I don't understand how this is even possible. I thought ONLY the controller can interact with the View? How are routes interacting with the view? Does this mean any class in our app can call View::make and control what View template is rendered?

This raises the even larger question of what is the routes returning to? In other words, when our Laravel server gets a request, something in our server pings the routes and our routes returns a template. What is routes returning the template too? I'm presuming it is index.php, I know there are a lot of bootstrapping methods in there. Can someone explain the internal structure of how Laravel works and why we can render views from routes?

Answer 1

Laravel intentionally makes this possible for the sake of flexibility. That said, you'll want to let a controller return a view response in most cases.

There are times where this flexibility comes in handy; say you want to quickly setup a route to output some debug data. Building a controller action and view template would be overkill in this case when you can just output it directly from your route definition. There are other cases too, but the route -> controller -> view method handles most use cases.

Answer 2

Actually, when you make a request to your Laravel application the request goes through route matching and if the matching route found then the framework invokes the handler/action registered for that route. So, it's actually the handler and a handler could be anything which is callable . So, when you declare a route like this:

Route::get('url', 'action');

The framework just searches for the requested route and if that is available in the Route Collection then it invokes/calls/runs that action/handler and the handler returns the response ( View ). So, if it's somethiong like this;

Route::get('url', 'myHandler');

function myHandler()
{
    //...
    return View::make(...);
}

In this case your execution scope is the function and if it's a class method then the scope is different, but in both cases the handler is taking the control to return the response, that's all. So, while it's possible to return a View from a named function then it's also possible to return a View from an anonymous function as well. If you can access/use something (Some other class such as a service class for something) from your execution scope then it's possible to be used. The difference between a function and a class method is the scope . So it's possible and easy and also useful in some cases (for a single page or a small application) but not recommended way and neither it's good practice. Try to use a class instead of an anonymous function.

Why does Laravel allow us to render views in routes?

It's a framework and in other words, it's a toolbox with so many tools and this is (the question you asked) just another tool which increases it's (the framework's) usefulness. It's not the toolbox's job to make a better application but your's and the toolbox is just a helper which saves your effort and time to be more productive. So, you have shortcuts but you need to chose the right thing wisely.

Answer 3

Request lifecycle is quite well explained in Laravel documentation: http://laravel.com/docs/4.2/lifecycle

Short answer: routes can return response (ie string, view), or can load controller which can return response as well. It's probably not very good practise to return view directly from routes, but can be useful in some cases.