PHP MVC SERIES: How to use MVC Structured Codebase in PHP (PART 2)

What Will I Learn?

• You will learn how to create an MVC structured codebase in php

Requirements

• WAMP/MAMP/LAMP/XAMP or any other PHP/MYSQL STACK

Difficulty

• Intermediate

Tutorial Contents

This tutorial is a continuation of the previous tutorial , in the last tutorial , we prepared the MODEL , VIEWS and CONTROLLER aspect of the MVC structure. In this tutorial, we will be connecting the MODEL to the VIEWS via the CONTROLLER.

STEP 1: FILL IN THE INDEX FILE

In our last tutorial ,we created an empty index.php, in this tutorial , we will be filling this file up now. Note that this file will be treating and receiving any url request sent into the application.

Below are the codes to be filled in:

<?php
include ('models/logic.php');
  if (isset($_GET['controller']) && isset($_GET['action'])) {
    $controller = $_GET['controller'];
    $action     = $_GET['action'];
  }
  else {
    $controller = 'pages';
    $action     = 'home';
  }
  require_once('views/layout.php');
?>

include ('models/logic.php'); : this includes the logic file which controls how the whole application works

$_GET['controller'] : refers to the controller file that will be used , where $_GET['controller'] will refer to the prefix of the controller file. If you checked our last tutorial, we only have one contoller file, which is pages_controller.php , this shows that the $_GET['controller'] is pages , meaning we might need to create a new controller file if the $_GET['controller'] is expected to be something else.

$_GET['action']: refers to the file that will be served in the function that will be served in PagesController Class, in our last tutorial, we had a home method and an error method , meaning the two actions expected were home and method.

else {$controller = 'pages';$action = 'home';} : This acts as a default controller file and method when $_GET['controller'] and $_GET['action'] are not specified.

require_once('views/layout.php'); : This serves layout.php that was explained in the last tutorial, it creates the layout of the view, layout.php contains <?php require_once('routes.php'); ?> which controls how the VIEWS are being processed.

STEP 2: CREATE & FILL IN THE ROUTE FILE

NOTE: the routes.php file exist in the root folder of the project with the index.php. To make things clear, the root folder will be structured as show in the picture below:

Now , let's fill in the route.php code:

<?php
  function call($controller, $action) {
    require_once('controllers/' . $controller . '_controller.php');
    switch($controller) {
      case 'pages':
        $controller = new PagesController();
      break;
    }
    $controller->{ $action }();
  }
  $controllers = array('pages' => ['home', 'error']);
  if (array_key_exists($controller, $controllers)) {
    if (in_array($action, $controllers[$controller])) {
      call($controller, $action);
    } else {
      call('pages', 'error');
    }
  } else {
    call('pages', 'error');
  }
?>

If you look through this codes, they are really very self-explanatory. I previously explained how the controller page is being served based on $controller and $action, if you look through this code above properly, you will discover that the function call() helps to refer to the right controller file via $controller variable and also pull the right method via $action.

It's crystal clear that we are done with LOGIC and VIEWS has now being connected via the use of CONTROLLER but to make things clear , I will re-explain two things in a concise form:

• THE FOLDER STRUCTURE
• THE REQUEST PATH

THE FOLDER STRUCTURE

• ROOT FOLDER
  

• CONTROLLER FOLDER
  

• MODEL FOLDER
  

• VIEWS FOLDER
  

THE REQUEST PATH

This is just an explanatory analysis of the request is recieved and treated through out the application.

• INDEX receives the request and then specifies the Controller and the Action
• LAYOUT receives the Contoller and action and passes it to ROUTE
• ROUTE uses the Controler variable to call the right controller and then use the action to call the right method in the controller file
• Then , the ouput of ROUTE is served in the layout.php and then the request is therefore served approriately.

That's all.

Please, read through the tutorial on emore time starting from the first to get a complete analysis of the MVC structure works

MVC SERIES: How to use MVC Structured Codebase in PHP (PART 1)

Curriculum

PHP MVC SERIES

• PHP MVC SERIES: How to use MVC Structured Codebase in PHP (PART 1)

PHP FORM SERIES

• PHP FORM SERIES: How to receive form data in PHP (POST AND GET METHOD)
• PHP FORM SERIES: How to format form data
• PHP FORM SERIES: How to insert data into database

PHP REGEX

• PHP REGEX: SETTING REGEX RULES

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