MVC Blog - How to include a header\ footer\ other.php file - php

Question

Following this tutorial http://johnsquibb.com/tutorials/mvc-framework-in-1-hour-part-one Im trying to write my first MVC Blog.
I understood how it works, router.php Calls the suitable page controller. This controller calls the model, Then calls the View page with the returned value.
My question is, What if I want to add to the same news.php page a header\footer. Normally I would write "include("header.php"). But now when using MVC, how could I implement that?
These are my files:
router.php:
<?php
/**
* This controller routes all incoming requests to the appropriate controller
*/
//Automatically includes files containing classes that are called
//fetch the passed request
$pageURL = $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
$path_parts = pathinfo($pageURL);
$page_name = $path_parts['filename'];
$parsed = explode('?' , $page_name);
//the page is the first element
$page = array_shift($parsed);
// If there is any variables, GET them.
if(!empty($parsed))
{
$parsed = explode('&' , $parsed[0]);
$getVars = array();
foreach ($parsed as $argument)
{
//explode GET vars along '=' symbol to separate variable, values
list($variable , $value) = explode('=' , $argument);
$getVars[$variable] = urldecode($value);
}
}
//compute the path to the suitable file
$target ='controllers/' . $page . '_controller.php';
//get target controller
if (file_exists($target))
{
include_once($target);
//modify page to fit naming convention
$class = ucfirst($page) . '_Controller';
//instantiate the appropriate class
if (class_exists($class))
{
$controller = new $class;
}
else
{
//did we name our class correctly?
die('class does not exist!');
}
}
else
{
//can't find the file in 'controllers'!
die('page does not exist!');
}
//once we have the controller instantiated, execute the default function
//pass any GET varaibles to the main method
$controller->main($getVars);
// AutoLoad
function __autoload($className)
{
// Parse out filename where class should be located
// This supports names like 'Example_Model' as well as 'Example_Two_Model'
list($suffix, $filename) = preg_split('/_/', strrev($className), 2);
$filename = strrev($filename);
$suffix = strrev($suffix);
//select the folder where class should be located based on suffix
switch (strtolower($suffix))
{
case 'model':
$folder = '/models/';
$filename = ($className);
break;
case 'library':
$folder = '/libraries/';
break;
case 'driver':
$folder = '/libraries/drivers/';
break;
}
//compose file name
$file = SERVER_ROOT . $folder . strtolower($filename) . '.php';
//fetch file
if (file_exists($file))
{
//get file
include_once($file);
}
else
{
//file does not exist!
die("File '$filename' containing class '$className' not found in
'$folder'.");
}
}
?>
post_controller.php
<?php
/**
* This file handles the retrieval and serving of posts posts
*/
class Posts_Controller
{
/**
* This template variable will hold the 'view' portion of our MVC for this
* controller
*/
public $template = 'posts';
/**
* This is the default function that will be called by router.php
*
* #param array $getVars the GET variables posted to index.php
*/
public function main(array $getVars)
{
//$b_controller =new Bottom_Bar_Controller;
//$b_controller->main($getVars);
$postsModel = new Posts_Model;
//get an post
$post = $postsModel->get_post($getVars['id']);
//create a new view and pass it our template
$header = new View_Model('header_template');
$bottom_bar = new View_Model('bottom_bar');
$view = new View_Model($this->template);
//assign post data to view
$view->assign('header', $header->render(FALSE));
$view->assign('bottom', $bottom_bar->render(FALSE));
$view->assign('title' , $post['title']);
$view->assign('content' , $post['content']);
$view->assign('date' , $post['date']);
$view->assign('by' , $post['added_by']);
$view->render();
}
}
posts_model.php
<?php
/**
* The Posts Model does the back-end heavy lifting for the Posts Controller
*/
class Posts_Model
{
/**
* Holds instance of database connection
*/
private $db;
public function __construct()
{
$this->db = new MysqlImproved_Driver;
}
/**
* Fetches article based on supplied name
*
* #param string $author
*
* #return array $article
*/
public function get_post($id)
{
//connect to database
$this->db->connect();
//sanitize data
$author = $this->db->escape($id);
//prepare query
$this->db->prepare
(
"
SELECT * FROM `posts`
WHERE
`id` = '$id'
LIMIT 1
;
"
);
//execute query
$this->db->query();
$article = $this->db->fetch('array');
return $article;
}
}
?>
view_model.php
<?php
/**
* Handles the view functionality of our MVC framework
*/
class View_Model
{
/**
* Holds variables assigned to template
*/
private $data = array();
/**
* Holds render status of view.
*/
private $render = FALSE;
/**
* Accept a template to load
*/
public function __construct($template)
{
//compose file name
$file = SERVER_ROOT . '/views/' . strtolower($template) . '.php';
if (file_exists($file))
{
/**
* trigger render to include file when this model is destroyed
* if we render it now, we wouldn't be able to assign variables
* to the view!
*/
$this->render = $file;
}
}
/**
* Receives assignments from controller and stores in local data array
*
* #param $variable
* #param $value
*/
public function assign($variable , $value)
{
$this->data[$variable] = $value;
}
/**
* Render the output directly to the page, or optionally, return the
* generated output to caller.
*
* #param $direct_output Set to any non-TRUE value to have the
* output returned rather than displayed directly.
*/
public function render($direct_output = TRUE)
{
// Turn output buffering on, capturing all output
if ($direct_output !== TRUE)
{
ob_start();
}
// Parse data variables into local variables
$data = $this->data;
// Get template
include($this->render);
// Get the contents of the buffer and return it
if ($direct_output !== TRUE)
{
return ob_get_clean();
}
}
public function __destruct()
{
}
}
posts.php
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link href="../style/style.css" rel="stylesheet" type="text/css" media="screen" />
<title> Posts (View)</title>
</head>
<body>
<div id="main">
<div class="container">
<?=$data['header'];?>
<div id="content">
<div class="content-background">
<h2> <?=$data['title'];?></h2>
<h4> <?=$data['date'];?> </h4>
<p><?=$data['content'];?></p>
</div>
</div>
</div>
</div>
</body>
</html>

Answer 1

Part of the problem is, that your tutorial has a pretty primitive interpretation of MVC-inspired design pattern (you actually cannot implement classical MVC in PHP, but there are patterns, that are based on it).
View is not just a template. Views are supposed to be class instances, which contain all presentation logic and deal with multiple templates. What you actually have there is a layout template which contains posts template.
// class \Application\View\Posts
public function render()
{
$layout = new Template( $this->defaultTemplateDirectory . 'layout.html');
$content = new Template( $this->defaultTemplateDirectory . 'posts.html' );
$layout->assign( 'content' , $content->render() );
return $layout->render();
}
Also, one of the things, that a view instance should do, is requesting information from the model layer.
Few materials that you might find useful:
Model-View-Confusion part 1: Why the model is accessed by the view in MVC
Simple PHP Template Engine
How should a model be structured in MVC?
And if you want to expand you knowledge in OOP, this post contains a list of recommended lectures and books.

Answer 2

There is no good solution in the MVC structure for that. You can find a solution in every framework. In CakePHP for example you can use an AppController, a controller which is always called for every requests. Sort of base controller.
But no, not very nice to do.
Most simple one is to ask the data directly from the view. That sounds weird but it is accepted in the MVC structure. So in your view you call $News->getLatestItems(10); and work with them.
I don't like it but it works.
If you have lots of widgets and blocks MVC alone might just not be the right structure. Then you could take a look at things like: http://techportal.inviqa.com/2010/02/22/scaling-web-applications-with-hmvc/ which is a derivate of MVC.
Another solution which you see more and more: Request it via AJAX calls. So just load them after the page has loaded. That way you also solve the issue since one MVC request then becomes multiple MVC requests.