Views in CI

Why I Copy other People’s Writings

A view is simply a web page, or a page fragment, like a header, footer, sidebar, etc. In fact, views can flexibly be embedded within other views (within other views, etc., etc.) if you need this type of hierarchy.

Views are never called directly, they must be loaded by a controller. Remember that in an MVC framework, the Controller acts as the traffic cop, so it is responsible for fetching a particular view.

Using the example controller you created in the controller page, let’s add a view to it.

Creating a View

Using your text editor, create a file called blogview.php, and put this in it:

<html>
<head>
<title>My Blog</title>
</head>
<body>
	<h1>Welcome to my Blog!</h1>
</body>
</html>

Then save the file in your application/views/ folder.

Loading a View

To load a particular view file you will use the following function:

$this->load->view('name');

Where name is the name of your view file. Note: The .php file extension does not need to be specified unless you use something other than .php.

Now, open the controller file you made earlier called blog.php, and replace the echo statement with the view loading function:

<?php
class Blog extends CI_Controller {

	function index()
	{
		$this->load->view('blogview');
	}
}
?>

If you visit your site using the URL you did earlier you should see your new view. The URL was similar to this:

example.com/index.php/blog/

Loading multiple views

CodeIgniter will intelligently handle multiple calls to $this->load->view from within a controller. If more than one call happens they will be appended together. For example, you may wish to have a header view, a menu view, a content view, and a footer view. That might look something like this:

<?php

class Page extends CI_Controller {

   function index()
   {
      $data['page_title'] = 'Your title';
      $this->load->view('header');
      $this->load->view('menu');
      $this->load->view('content', $data);
      $this->load->view('footer');
   }

}
?>

In the example above, we are using “dynamically added data”, which you will see below.

Storing Views within Sub-folders

Your view files can also be stored within sub-folders if you prefer that type of organization. When doing so you will need to include the folder name loading the view. Example:

$this->load->view('folder_name/file_name');

Adding Dynamic Data to the View

Data is passed from the controller to the view by way of an array or an object in the second parameter of the view loading function. Here is an example using an array:

$data = array(
               'title' => 'My Title',
               'heading' => 'My Heading',
               'message' => 'My Message'
          );

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

And here’s an example using an object:

$data = new Someclass();
$this->load->view('blogview', $data);

Note: If you use an object, the class variables will be turned into array elements.

Let’s try it with your controller file. Open it and add this code:

<?php
class Blog extends CI_Controller {

	function index()
	{
		$data['title'] = "My Real Title";
		$data['heading'] = "My Real Heading";

		$this->load->view('blogview', $data);
	}
}
?>

Now open your view file and change the text to variables that correspond to the array keys in your data:

<html>
<head>
<title><?php echo $title;?></title>
</head>
<body>
	<h1><?php echo $heading;?></h1>
</body>
</html>

Then load the page at the URL you’ve been using and you should see the variables replaced.

Creating Loops

The data array you pass to your view files is not limited to simple variables. You can pass multi dimensional arrays, which can be looped to generate multiple rows. For example, if you pull data from your database it will typically be in the form of a multi-dimensional array.

Here’s a simple example. Add this to your controller:

<?php
class Blog extends CI_Controller {

	function index()
	{
		$data['todo_list'] = array('Clean House', 'Call Mom', 'Run Errands');

		$data['title'] = "My Real Title";
		$data['heading'] = "My Real Heading";

		$this->load->view('blogview', $data);
	}
}
?>

Now open your view file and create a loop:

<html>
<head>
<title><?php echo $title;?></title>
</head>
<body>
<h1><?php echo $heading;?></h1>

<h3>My Todo List</h3>

<ul>
<?php foreach ($todo_list as $item):?>

<li><?php echo $item;?></li>

<?php endforeach;?>
</ul>

</body>
</html>

Note:
You’ll notice that in the example above we are using PHP’s alternative syntax. If you are not familiar with it you can read about it here.

Returning views as data

There is a third optional parameter lets you change the behavior of the function so that it returns data as a string rather than sending it to your browser. This can be useful if you want to process the data in some way. If you set the parameter to true (boolean) it will return data. The default behavior is false, which sends it to your browser. Remember to assign it to a variable if you want the data returned:

$string = $this->load->view('myfile', '', true);
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About samehramzylabib

See About on https://samehramzylabib.wordpress.com
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