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| author | Eric Barnes <eric@ericlbarnes.com> | 2011-11-27 06:30:22 +0100 |
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| committer | Eric Barnes <eric@ericlbarnes.com> | 2011-11-27 06:30:22 +0100 |
| commit | 7e66dda705743cbfe1d522ddb73e5694006ec42c (patch) | |
| tree | c08b63deb28c09ec49d9173280f1ca234debfe50 /user_guide_src/source/general/views.rst | |
| parent | 7eceb03f083643254c7393c6b5ebe539e344a1ba (diff) | |
| parent | e101593561a10632c1d63180436b19f1d7115046 (diff) | |
Merge branch 'refs/heads/develop' into feature/unit-tests
Conflicts:
user_guide/helpers/number_helper.html
Diffstat (limited to 'user_guide_src/source/general/views.rst')
| -rw-r--r-- | user_guide_src/source/general/views.rst | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/user_guide_src/source/general/views.rst b/user_guide_src/source/general/views.rst new file mode 100644 index 000000000..dc65f6c4f --- /dev/null +++ b/user_guide_src/source/general/views.rst @@ -0,0 +1,216 @@ +##### +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 :doc:`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); + |