Introduction to Controllers

Controllers are responsible for controlling the flow of the application execution. When you make a request, a controller is responsible for returning the response to that request. The controller can perform one or more actions.

Creating a controller

A controller file can be created manually or automatically using xjs-cli make:controller command.

Xpresser has 3 types of controllers.

• A Class file controller
• An Object file controller
• An Object with custom services controller

Don't get overwhelmed, they all serve the same purpose with just a little preference difference, For a start we will be using a the class based controllers in our documentation.

Class file controller

Filename: PostsController.js

const {ControllerClass} = require('xpresser');

class PostController extends ControllerClass {
    all() { /** take action here **/ }
    static create() { /** same as above but static **/}
}

module.exports = PostController;

The above is an example of a class file controller.

The class file controller MUST extend xpresser's base controller (ControllerClass), this extension lets xpresser know that you are using a class and not an object. this is because javascript has no official way of checking if a variable is a class.

The PostController contains a static method and a non-static method, both works exactly the same way. Usage depends on your preference.

Handling Requests.

In the method of your controller class is where you are likely to spend most of your time because it is where the action for a routed request is taken place.

You can route to a controller action like so:

$.router.get('/posts/all', 'PostsController@all');

Now, when a request matches the specified route URI, the all method on the PostsController class will be executed.

We can send a basic response like so

const {ControllerClass} = require('xpresser');

class PostController extends ControllerClass {

    all(http) {
        http.send("List of all posts.");
        // Or like in express
        http.res.send("List of all posts.")
    }

}

The http variable includes express req and res variables with more functions/helpers

--- To be continued ---