user_guide_src/source/general/views.rst - code-igniter-v3-giggi - Gitiles

 #####
 Views
 #####

 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
 :doc:`controller <controllers>`. Remember that in an MVC framework, the
 Controller acts as the traffic cop, so it is responsible for fetching a
 particular view. If you have not read the
 :doc:`Controllers <controllers>` page you should do so before
 continuing.

 Using the example controller you created in the
 :doc:`controller <controllers>` 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/* directory.

 Loading a View
 ==============

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

 	$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 method::

 	<?php
 	class Blog extends CI_Controller {

 		public 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 {

 		public 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-directories
 ====================================

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

 	$this->load->view('directory_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 method. 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 add this code::

 	<?php
 	class Blog extends CI_Controller {

 		public 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 {

 		public 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 :doc:`here <alternative_php>`.

 Returning views as data
 =======================

 There is a third **optional** parameter lets you change the behavior of
 the method 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);
	#####
	Views
	#####

	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
	:doc:`controller <controllers>`. Remember that in an MVC framework, the
	Controller acts as the traffic cop, so it is responsible for fetching a
	particular view. If you have not read the
	:doc:`Controllers <controllers>` page you should do so before
	continuing.

	Using the example controller you created in the
	:doc:`controller <controllers>` 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/ directory.

	Loading a View
	==============

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

	$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 method::

	<?php
	class Blog extends CI_Controller {

	public 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 {

	public 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-directories
	====================================

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

	$this->load->view('directory_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 method. 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 add this code::

	<?php
	class Blog extends CI_Controller {

	public 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 {

	public 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 :doc:`here <alternative_php>`.

	Returning views as data
	=======================

	There is a third optional parameter lets you change the behavior of
	the method 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);