Review: returning values with a previous method - PHP

Manipulating views with CodeIgniter is a straightforward process. In a typical situation, there’s a model that fetches some rows from one or more database tables, and a view file that receives this data through a controller class, which is finally displayed on screen, generally in the form of an HTML page. However, CodeIgniter gives PHP programmers enough freedom to handle views in several useful ways, which can speed up the development of web applications. Therefore, if you’re taking your first steps with CI and wish to learn some handy approaches that will help you work with views in a truly painless fashion, then start reading this tutorial now!

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By: Alejandro Gervasio

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April 16, 2009

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In the introduction, I mentioned that it’s possible to remove from a view the PHP loop that iterates over the database rows, based on the structure of the web application developed in the previous article. But before I show you how to do that, I’m going to reintroduce the full source code of this sample PHP program, so you can recall how it was developed initially.

That being said, here are all the files that comprise this web application:

(‘webpage.php’ file – located at /application/controllers/ folder)

<?php

class WebPage extends Controller{

function WebPage(){

// load controller parent

parent::Controller();

// load libraries here

$this->load->database();

// load helpers here

}

// generate web page using partial sections

function index(){

// generate header section

$data['header']=$this->load->view('header_view',array('header'=>'Header Section'),TRUE);

// generate content section

$data['content']=$this->load->view('content_view',array('users'=>$this->db->get('users')),TRUE);

// generate footer section

$data['footer']=$this->load->view('footer_view',array('footer'=>'Footer Section'),TRUE);

// generate full web page

$this->load->view('main_page',$data);

}

(‘main_page.php’ file - located at /application/views/ folder)

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<head>

<title>Sample Web Page</title>

body{

padding: 0;

margin: 0;

background: #999;

}

#container{

width: 600px;

margin: 0 auto;

}

#header{

padding: 10px;

background: #eee;

}

#content{

padding: 10px;

background: #9cf;

}

#footer{

padding: 10px;

background: #eee;

}

h1{

font: bold 2em Arial, Helvetica, sans-serif;

margin: 0 0 18px 0;

color: #039;

}

h2{

font: bold 1.5em Arial, Helvetica, sans-serif;

margin: 0 0 18px 0;

}

font: normal .8em Arial, Helvetica, sans-serif;

margin: 0 0 18px 0;

}

</style>

</head>

<body>

<?php

echo $header.$content.$footer;

</div>

</body>

</html>

(‘header_view.php’ file - located at /application/views/ folder)

<p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut.</p>

</div>

(‘content_view.php’ file - located at /application/views/ folder)

<?php if($users->num_rows > 0):?>

<?php foreach($users->result() as $user):?>

<p><strong>First Name: </strong><?php echo $user->firstname;?></p>

<p><strong>Last Name: </strong><?php echo $user->lastname;?></p>

<p><strong>Email: </strong><?php echo $user->email;?></p>

<hr />

<?php endforeach;?>

<?php endif;?>

</div>

(‘footer_view.php’ file - located at /application/views/ folder)

<p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut.</p>

</div>

Having listed all of the source files that compose the MySQL-driven application built during the previous tutorial of this series, it’s worthwhile to stress one point regarding the way it’s been structured: as you can see, within the “content_view.php” view file there’s a “foreach” construct that loops over the rows fetched from a “users” MySQL table.

This is a valid approach, used frequently for constructing views. However, it’s also feasible to implement a little twist here and remove the loop from this specific view, in this way increasing the level of separation between the application’s logic and its visual presentation even more.

Provided that you’re interested in learning how to turn the concept deployed above into functional code, in the next section I’ll be creating a brand new view file, in addition to modifying slightly the signature of the “WebPage” controller class.

Click on the link below and continue reading.

Next: Moving presentation logic out of views >>