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diff --git a/user_guide_src/source/general/views.rst b/user_guide_src/source/general/views.rst new file mode 100644 index 000000000..cb60ce20f --- /dev/null +++ b/user_guide_src/source/general/views.rst @@ -0,0 +1,138 @@ +##### +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/ 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', $data); + +Note: If you use an object, the class variables will be turned into +array elements. + +Let's try it with your controller file. Open it add this code: + +<?php class Blog extends CI_Controller { function index() { +$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 </general/alternative_php>`. + +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); + |