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Joël Cox	b430ecd	2011-08-23 14:54:42 +0200	[diff] [blame]	31	<td><h1>CodeIgniter User Guide Version 2.0.3</h1></td>
Joël Cox	f27bcf3	2011-08-22 22:29:06 +0200	[diff] [blame]	32	<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td>
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Joël Cox	7bd6335	2011-08-27 20:21:19 +0200	[diff] [blame]	45	<a href="index.html">Tutorial</a>  ›
Joël Cox	f27bcf3	2011-08-22 22:29:06 +0200	[diff] [blame]	46	Static pages
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				59
				60	<h1>Tutorial − Static pages</h1>
				61
				62	<p class="important"><strong>Note:</strong> This tutorial assumes you've downloaded CodeIgniter and <a href="../installation/index.html">installed the framework</a> in your development environment.</p>
				63
				64	<p>The first thing you're going to do is set up a <strong>controller</strong> to handle static pages.
				65	A controller is simply a class that helps delegate work. It is the glue of your
				66	web application.</p>
				67
				68	<p>For example, when a call is made to: <code>http://example.com/news/latest/10</code> We might imagine
				69	that there is a controller named "news". The method being called on news
				70	would be "latest". The news method's job could be to grab 10
				71	news items, and render them on the page. Very often in MVC, you'll see URL
				72	patterns that match: <code>http://example.com/[controller-class]/[controller-method]/[arguments]</code>
				73	As URL schemes become more complex, this may change. But for now, this is all we will need to know.</p>
				74
				75	<p>Create a file at <dfn>application/controllers/pages.php</dfn> with the following code.</p>
				76
				77	<textarea class="textarea" style="width:100%" cols="50" rows="10">
				78	<?php
				79
				80	class Pages extends CI_Controller {
				81
Joël Cox	7bd6335	2011-08-27 20:21:19 +0200	[diff] [blame]	82	public function view($page = 'home')
Joël Cox	f27bcf3	2011-08-22 22:29:06 +0200	[diff] [blame]	83	{
				84
				85	}
				86	}
				87	</textarea>
				88
				89	<p>You have created a class named "pages", with a view method that accepts one argument named <var>$page</var>.
				90	The pages class is extending the CI_Controller class.
				91	This means that the new pages class can access the methods and variables defined in the CI_Controller class
				92	(<dfn>system/core/Controller.php</dfn>).</p>
				93
				94	<p>The <strong>controller is what will become the center of every request</strong> to your web application.
				95	In very technical CodeIgniter discussions, it may be referred to as the <em>super object</em>.
				96	Like any php class, you refer to it within your controllers as <var>$this</var>.
				97	Referring to <var>$this</var> is how you will load libraries, views, and generally
				98	command the framework.</p>
				99
				100	<p>Now you've created your first method, it's time to make some basic page templates.
				101	We will be creating two "views" (page templates) that act as our page footer and header.</p>
				102
				103	<p>Create the header at <dfn>application/views/templates/header.php</dfn> and add the following code.</p>
				104
				105	<textarea class="textarea" style="width:100%" cols="50" rows="8">
				106	<html>
				107	<head>
				108	<title><?php echo $title ?> - CodeIgniter 2 Tutorial</title>
				109	</head>
				110	<body>
				111	<h1>CodeIgniter 2 Tutorial</h1>
				112
				113	</textarea>
				114
				115	<p>The header contains the basic HTML code that you'll want to display before loading the main view, together with a heading.
				116	It will also output the <var>$title</var> variable, which we'll define later in the controller.
				117	Now create a footer at <dfn>application/views/templates/footer.php</dfn> that includes the following code:</p>
				118
				119	<textarea class="textarea" style="width:100%" cols="50" rows="4">
				120	<strong>&copy; 2011</strong>
				121	</body>
				122	</html>
				123	</textarea>
				124
				125	<h2>Adding logic to the controller</h2>
				126
				127	<p>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.
				128	The static page templates will be located in the <dfn>application/views/pages/</dfn> directory.</p>
				129
				130	<p>In that directory, create two files named <dfn>home.php</dfn> and <dfn>about.php</dfn>.
				131	Within those files, type some text − anything you'd like − and save them.
				132	If you like to be particularly un-original, try "Hello World!".</p>
				133
				134	<p>In order to load those pages, you'll have to check whether the requested page actually exists:</p>
				135
				136	<pre>
Joël Cox	7bd6335	2011-08-27 20:21:19 +0200	[diff] [blame]	137	public function view($page = 'home')
Joël Cox	f27bcf3	2011-08-22 22:29:06 +0200	[diff] [blame]	138	{
				139
Joël Cox	7bd6335	2011-08-27 20:21:19 +0200	[diff] [blame]	140	if ( ! file_exists('application/views/pages/'.$page.'.php'))
Joël Cox	f27bcf3	2011-08-22 22:29:06 +0200	[diff] [blame]	141	{
				142	// Whoops, we don't have a page for that!
				143	show_404();
				144	}
				145
				146	$data['title'] = ucfirst($page); // Capitalize the first letter
				147
				148	$this->load->view('templates/header', $data);
Joël Cox	7bd6335	2011-08-27 20:21:19 +0200	[diff] [blame]	149	$this->load->view('pages/'.$page, $data);
Joël Cox	f27bcf3	2011-08-22 22:29:06 +0200	[diff] [blame]	150	$this->load->view('templates/footer', $data);
Joël Cox	7bd6335	2011-08-27 20:21:19 +0200	[diff] [blame]	151
				152	}
Joël Cox	f27bcf3	2011-08-22 22:29:06 +0200	[diff] [blame]	153	</pre>
				154
				155	<p>Now, when the page does exist, it is loaded, including the header and footer, and displayed to the user. If the page doesn't exist, a "404 Page not found" error is shown.</p>
				156
				157	<p>The first line in this method checks whether the page actually exists. PHP's native <var>file_exists()</var> function is used to check whether the file is where it's expected to be. <var>show_404()</var> is a built-in CodeIgniter function that renders the default error page.</p>
				158
				159	<p>In the header template, the <var>$title</var> 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 <var>$data</var> array.</p>
				160
				161	<p>The last thing that has to be done is loading the views in the order they should be displayed.
				162	The second parameter in the <var>view()</var> method is used to pass values to the view. Each value in the <var>$data</var> array is assigned to a variable with the name of its key. So the value of <var>$data['title']</var> in the controller is equivalent to $title in the view.<p>
				163
				164	<h2>Routing</h2>
				165
				166	<p>The controller is now functioning! Point your browser to <dfn>[your-site-url]index.php/pages/view</dfn> to see your page. When you visit <dfn>index.php/pages/view/about</dfn> you'll see the about page, again including the header and footer.</p>
				167
				168	<p>Using custom routing rules, you have the power to map any URI to any controller and method, and break free from the normal convention:
				169	<code>http://example.com/[controller-class]/[controller-method]/[arguments]</code></p>
				170
				171	<p>Let's do that. Open the routing file located at <dfn>application/config/routes.php</dfn> and add the following two lines. Remove all other code that sets any element in the <var>$route</var> array.</p>
				172
				173	<pre>
Joël Cox	18cb551	2011-09-07 21:17:37 +0200	[diff] [blame^]	174	$route['default_controller'] = 'pages/view';
Joël Cox	f27bcf3	2011-08-22 22:29:06 +0200	[diff] [blame]	175	$route['(:any)'] = 'pages/view/$1';
				176	</pre>
				177
				178	<p>CodeIgniter reads its routing rules from top to bottom and routes the request to the first matching rule. Each rule is a regular expression
				179	(left-side) mapped to a controller and method name separated by slashes (right-side).
				180	When a request comes in, CodeIgniter looks for the first match, and calls the appropriate controller and method, possibly with arguments.</p>
				181
				182	<p>More information about routing can be found in the URI Routing <a href="../general/routing.html">documentation</a>.</p>
				183
				184	<p>Here, the second rule in the <var>$routes</var> array matches <strong>any</strong> request using the wildcard string <dfn>(:any)</dfn>.
				185	and passes the parameter to the view() method of the pages class.</p>
				186
				187	<p>Now visit <dfn>index.php/about</dfn>. Did it get routed correctly to the <var>view()</var> method
				188	in the pages controller? Awesome!</p>
				189
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Joël Cox	7bd6335	2011-08-27 20:21:19 +0200	[diff] [blame]	196	Previous Topic:  <a href="index.html">Introduction</a>
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