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diff --git a/user_guide_src/source/tutorial/static_pages.rst b/user_guide_src/source/tutorial/static_pages.rst new file mode 100644 index 000000000..708eaeb7b --- /dev/null +++ b/user_guide_src/source/tutorial/static_pages.rst @@ -0,0 +1,170 @@ +############ +Static pages +############ + +**Note:** This tutorial assumes you've downloaded CodeIgniter and +`installed the framework <../installation/index.html>`_ in your +development environment. + +The first thing you're going to do is set up a **controller** to handle +static pages. A controller is simply a class that helps delegate work. +It is the glue of your web application. + +For example, when a call is made to: +``http://example.com/news/latest/10`` We might imagine that there is a +controller named "news". The method being called on news would be +"latest". The news method's job could be to grab 10 news items, and +render them on the page. Very often in MVC, you'll see URL patterns that +match: +``http://example.com/[controller-class]/[controller-method]/[arguments]`` +As URL schemes become more complex, this may change. But for now, this +is all we will need to know. + +Create a file at application/controllers/pages.php with the following +code. + +:: + + <?php + class Pages extends CI_Controller { + + public function view($page = 'home') + { + + } + + } + +You have created a class named "pages", with a view method that accepts +one argument named $page. The pages class is extending the +CI_Controller class. This means that the new pages class can access the +methods and variables defined in the CI_Controller class +(system/core/Controller.php). + +The **controller is what will become the center of every request** to +your web application. In very technical CodeIgniter discussions, it may +be referred to as the *super object*. Like any php class, you refer to +it within your controllers as $this. Referring to $this is how you will +load libraries, views, and generally command the framework. + +Now you've created your first method, it's time to make some basic page +templates. We will be creating two "views" (page templates) that act as +our page footer and header. + +Create the header at application/views/templates/header.php and add the +following code. + +:: + + <html> + <head> + <title>CodeIgniter 2 Tutorial</title> + </head> + <body> + + <h1>CodeIgniter 2 Tutorial</h1> + +The header contains the basic HTML code that you'll want to display +before loading the main view, together with a heading. It will also +output the $title variable, which we'll define later in the controller. +Now create a footer at application/views/templates/footer.php that +includes the following code: + +:: + + <em>© 2012</em> + </body> + <html> + +Adding logic to the controller +------------------------------ + +Earlier you set up a controller with a view() method. The method accepts +one parameter, which is the name of the page to be loaded. The static +page templates will be located in the application/views/pages/ +directory. + +In that directory, create two files named home.php and about.php. Within +those files, type some text − anything you'd like − and save them. If +you like to be particularly un-original, try "Hello World!". + +In order to load those pages, you'll have to check whether the requested +page actually exists: + +:: + + <?php + public function view($page = 'home') + { + + if ( ! file_exists(APPPATH.'/views/pages/'.$page.'.php')) + { + // Whoops, we don't have a page for that! + show_404(); + } + + $data['title'] = ucfirst($page); // Capitalize the first letter + + $this->load->view('templates/header', $data); + $this->load->view('pages/'.$page, $data); + $this->load->view('templates/footer', $data); + + } + +Now, when the page does exist, it is loaded, including the header and +footer, and displayed to the user. If the page doesn't exist, a "404 +Page not found" error is shown. + +The first line in this method checks whether the page actually exists. +PHP's native file\_exists() function is used to check whether the file +is where it's expected to be. show\_404() is a built-in CodeIgniter +function that renders the default error page. + +In the header template, the $title variable was used to customize the +page title. The value of title is defined in this method, but instead of +assigning the value to a variable, it is assigned to the title element +in the $data array. + +The last thing that has to be done is loading the views in the order +they should be displayed. The second parameter in the view() method is +used to pass values to the view. Each value in the $data array is +assigned to a variable with the name of its key. So the value of +$data['title'] in the controller is equivalent to $title in the view. + +Routing +------- + +The controller is now functioning! Point your browser to +[your-site-url]index.php/pages/view to see your page. When you visit +index.php/pages/view/about you'll see the about page, again including +the header and footer. + +Using custom routing rules, you have the power to map any URI to any +controller and method, and break free from the normal convention: +``http://example.com/[controller-class]/[controller-method]/[arguments]`` + +Let's do that. Open the routing file located at +application/config/routes.php and add the following two lines. Remove +all other code that sets any element in the $route array. + +:: + + $route['default_controller'] = 'pages/view'; + $route['(:any)'] = 'pages/view/$1'; + +CodeIgniter reads its routing rules from top to bottom and routes the +request to the first matching rule. Each rule is a regular expression +(left-side) mapped to a controller and method name separated by slashes +(right-side). When a request comes in, CodeIgniter looks for the first +match, and calls the appropriate controller and method, possibly with +arguments. + +More information about routing can be found in the URI Routing +`documentation <../general/routing.html>`_. + +Here, the second rule in the $routes array matches **any** request using +the wildcard string (:any). and passes the parameter to the view() +method of the pages class. + +Now visit index.php/about. Did it get routed correctly to the view() +method in the pages controller? Awesome! |