# Controller

As a minimalist framework that mimics Sinatra, Pinatra does not provide the Controller and Model base components by default, but can be implemented with a simple DIY.

Below I will show how to use controllers in the Pinatra framework.

# The basic design of controllers in routing

Pinatra routing provides a very simple way to call Controller@method, which is followed by the following simple steps:

1. Define the root namespace of the controller. The default is '\', which is the root space.
2. When you get a response request like Controller@method, new a object, then call the method and pass in the parameters.

// Fake code
$a = $baseNameSpace.$controller; // '\NameSpace\HomeController';
$b = $method; // 'home'
(new $a)->$method($a, $b, $c ...);

# Using the controller

It takes three steps to load the controller into Pinatra.

# 1. Setting up a namespace

The main purpose of setting up a namespace is to autoload, which is to let us not need to manually require the file before calling the class.

The PSR-4 specification is to make the namespace as the same structure of the folder and file name, the most trouble-free. The PSR-0 specification allows each file to be set internally, with the disadvantage of rerun composer dump-autoload for each modification.

Pinatra recommends the PSR-4 autoloading specification as follows.

1. New controllers folder at the same level as the public folder
2. Modify composer.json to add the following:

"autoload": {
  "psr-4": {
    "Controllers\\": "controllers/"
  }
},

3. Run the command composer dump-autoload

# 2. Let Pinatra know

Add a line of code to public/index.php:

\Pinatra\Routing\Router::$baseNamespace = '\\Controllers\\';

# 3. try it

# Creating a controller

Create a controllers/HomeController.php file with the following contents:

<?php
namespace Controllers;

class HomeController
{
  public function home()
  {
    echo "Welcome to homepage!";
  }
}

# Create a route

get('home', 'HomeController@home');

# Test results

Visit http://0.0.0.0:8000/home to get the following page, success!