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| author | Derek Jones <derek.jones@ellislab.com> | 2011-10-05 20:34:52 +0200 |
|---|---|---|
| committer | Derek Jones <derek.jones@ellislab.com> | 2011-10-05 20:34:52 +0200 |
| commit | 8ede1a2ecbb62577afd32996956c5feaf7ddf9b6 (patch) | |
| tree | 2e960ec3b416b477f40bb546371f2d486f4a22f0 /user_guide/general/controllers.html | |
| parent | d1ecd5cd4ae6ab5d37df9fbda14b93977b9e743c (diff) | |
replacing the old HTML user guide with a Sphinx-managed user guide
Diffstat (limited to 'user_guide/general/controllers.html')
| -rw-r--r-- | user_guide/general/controllers.html | 388 |
1 files changed, 0 insertions, 388 deletions
diff --git a/user_guide/general/controllers.html b/user_guide/general/controllers.html deleted file mode 100644 index 2d525141c..000000000 --- a/user_guide/general/controllers.html +++ /dev/null @@ -1,388 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> -<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> -<head> - -<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> -<title>Controllers : CodeIgniter User Guide</title> - -<style type='text/css' media='all'>@import url('../userguide.css');</style> -<link rel='stylesheet' type='text/css' media='all' href='../userguide.css' /> - -<script type="text/javascript" src="../nav/nav.js"></script> -<script type="text/javascript" src="../nav/prototype.lite.js"></script> -<script type="text/javascript" src="../nav/moo.fx.js"></script> -<script type="text/javascript" src="../nav/user_guide_menu.js"></script> - -<meta http-equiv='expires' content='-1' /> -<meta http-equiv= 'pragma' content='no-cache' /> -<meta name='robots' content='all' /> -<meta name='author' content='ExpressionEngine Dev Team' /> -<meta name='description' content='CodeIgniter User Guide' /> - -</head> -<body> - -<!-- START NAVIGATION --> -<div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div> -<div id="nav2"><a name="top"></a><a href="javascript:void(0);" onclick="myHeight.toggle();"><img src="../images/nav_toggle_darker.jpg" width="154" height="43" border="0" title="Toggle Table of Contents" alt="Toggle Table of Contents" /></a></div> -<div id="masthead"> -<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> -<tr> -<td><h1>CodeIgniter User Guide Version 2.0.3</h1></td> -<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td> -</tr> -</table> -</div> -<!-- END NAVIGATION --> - - -<!-- START BREADCRUMB --> -<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> -<tr> -<td id="breadcrumb"> -<a href="http://codeigniter.com/">CodeIgniter Home</a> › -<a href="../index.html">User Guide Home</a> › -Controllers -</td> -<td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="codeigniter.com/user_guide/" />Search User Guide <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" /> <input type="submit" class="submit" name="sa" value="Go" /></form></td> -</tr> -</table> -<!-- END BREADCRUMB --> - -<br clear="all" /> - - -<!-- START CONTENT --> -<div id="content"> - -<h1>Controllers</h1> - -<p>Controllers are the heart of your application, as they determine how HTTP requests should be handled.</p> - - -<ul> -<li><a href="#what">What is a Controller?</a></li> -<li><a href="#hello">Hello World</a></li> -<li><a href="#functions">Functions</a></li> -<li><a href="#passinguri">Passing URI Segments to Your Functions</a></li> -<li><a href="#default">Defining a Default Controller</a></li> -<li><a href="#remapping">Remapping Function Calls</a></li> -<li><a href="#output">Controlling Output Data</a></li> -<li><a href="#private">Private Functions</a></li> -<li><a href="#subfolders">Organizing Controllers into Sub-folders</a></li> -<li><a href="#constructors">Class Constructors</a></li> -<li><a href="#reserved">Reserved Function Names</a></li> -</ul> - - -<a name="what"></a> -<h2>What is a Controller?</h2> - -<p><dfn>A Controller is simply a class file that is named in a way that can be associated with a URI.</dfn></p> - -<p>Consider this URI:</p> - -<code>example.com/index.php/<var>blog</var>/</code> - -<p>In the above example, CodeIgniter would attempt to find a controller named <dfn>blog.php</dfn> and load it.</p> - -<p><strong>When a controller's name matches the first segment of a URI, it will be loaded.</strong></p> - -<a name="hello"></a> -<h2>Let's try it: Hello World!</h2> - -<p>Let's create a simple controller so you can see it in action. Using your text editor, create a file called <dfn>blog.php</dfn>, and put the following code in it:</p> - - -<textarea class="textarea" style="width:100%" cols="50" rows="10"> -<?php -class Blog extends CI_Controller { - - public function index() - { - echo 'Hello World!'; - } -} -?> -</textarea> - - - -<p>Then save the file to your <dfn>application/controllers/</dfn> folder.</p> - -<p>Now visit the your site using a URL similar to this:</p> - -<code>example.com/index.php/<var>blog</var>/</code> - -<p>If you did it right, you should see <samp>Hello World!</samp>.</p> - -<p>Note: Class names must start with an uppercase letter. In other words, this is valid:</p> - -<code><?php<br /> -class <var>Blog</var> extends CI_Controller {<br /> -<br /> -}<br /> -?></code> - -<p>This is <strong>not</strong> valid:</p> - -<code><?php<br /> -class <var>blog</var> extends CI_Controller {<br /> -<br /> -}<br /> -?></code> - -<p>Also, always make sure your controller <dfn>extends</dfn> the parent controller class so that it can inherit all its functions.</p> - - - -<a name="functions"></a> -<h2>Functions</h2> - -<p>In the above example the function name is <dfn>index()</dfn>. The "index" function is always loaded by default if the -<strong>second segment</strong> of the URI is empty. Another way to show your "Hello World" message would be this:</p> - -<code>example.com/index.php/<var>blog</var>/<samp>index</samp>/</code> - -<p><strong>The second segment of the URI determines which function in the controller gets called.</strong></p> - -<p>Let's try it. Add a new function to your controller:</p> - - -<textarea class="textarea" style="width:100%" cols="50" rows="15"> -<?php -class Blog extends CI_Controller { - - public function index() - { - echo 'Hello World!'; - } - - public function comments() - { - echo 'Look at this!'; - } -} -?> -</textarea> - -<p>Now load the following URL to see the <dfn>comment</dfn> function:</p> - -<code>example.com/index.php/<var>blog</var>/<samp>comments</samp>/</code> - -<p>You should see your new message.</p> - -<a name="passinguri"></a> -<h2>Passing URI Segments to your Functions</h2> - -<p>If your URI contains more then two segments they will be passed to your function as parameters.</p> - -<p>For example, lets say you have a URI like this:</p> - -<code>example.com/index.php/<var>products</var>/<samp>shoes</samp>/<kbd>sandals</kbd>/<dfn>123</dfn></code> - -<p>Your function will be passed URI segments 3 and 4 ("sandals" and "123"):</p> - -<code> -<?php<br /> -class Products extends CI_Controller {<br /> -<br /> - public function shoes($sandals, $id)<br /> - {<br /> - echo $sandals;<br /> - echo $id;<br /> - }<br /> -}<br /> -?> -</code> - -<p class="important"><strong>Important:</strong> If you are using the <a href="routing.html">URI Routing</a> feature, the segments -passed to your function will be the re-routed ones.</p> - - -<a name="default"></a> -<h2>Defining a Default Controller</h2> - -<p>CodeIgniter can be told to load a default controller when a URI is not present, -as will be the case when only your site root URL is requested. To specify a default controller, open -your <dfn>application/config/routes.php</dfn> file and set this variable:</p> - -<code>$route['default_controller'] = '<var>Blog</var>';</code> - -<p>Where <var>Blog</var> is the name of the controller class you want used. If you now load your main index.php file without -specifying any URI segments you'll see your Hello World message by default.</p> - - - -<a name="remapping"></a> -<h2>Remapping Function Calls</h2> - -<p>As noted above, the second segment of the URI typically determines which function in the controller gets called. -CodeIgniter permits you to override this behavior through the use of the <kbd>_remap()</kbd> function:</p> - -<code>public function _remap()<br /> -{<br /> - // Some code here...<br /> -}</code> - -<p class="important"><strong>Important:</strong> If your controller contains a function named <kbd>_remap()</kbd>, it will <strong>always</strong> -get called regardless of what your URI contains. It overrides the normal behavior in which the URI determines which function is called, -allowing you to define your own function routing rules.</p> - -<p>The overridden function call (typically the second segment of the URI) will be passed as a parameter to the <kbd>_remap()</kbd> function:</p> - -<code>public function _remap(<var>$method</var>)<br /> -{<br /> - if ($method == 'some_method')<br /> - {<br /> - $this->$method();<br /> - }<br /> - else<br /> - {<br /> - $this->default_method();<br /> - }<br /> -}</code> - -<p>Any extra segments after the method name are passed into <kbd>_remap()</kbd> as an optional second parameter. This array can be used in combination with PHP's <a href="http://php.net/call_user_func_array">call_user_func_array</a> to emulate CodeIgniter's default behavior.</p> - -<code>public function _remap($method, $params = array())<br /> -{<br /> - $method = 'process_'.$method;<br /> - if (method_exists($this, $method))<br /> - {<br /> - return call_user_func_array(array($this, $method), $params);<br /> - }<br /> - show_404();<br /> -}</code> - - -<a name="output"></a> -<h2>Processing Output</h2> - -<p>CodeIgniter has an output class that takes care of sending your final rendered data to the web browser automatically. More information on this can be found in the -<a href="views.html">Views</a> and <a href="../libraries/output.html">Output class</a> pages. In some cases, however, you might want to -post-process the finalized data in some way and send it to the browser yourself. CodeIgniter permits you to -add a function named <dfn>_output()</dfn> to your controller that will receive the finalized output data.</p> - -<p><strong>Important:</strong> If your controller contains a function named <kbd>_output()</kbd>, it will <strong>always</strong> -be called by the output class instead of echoing the finalized data directly. The first parameter of the function will contain the finalized output.</p> - -<p>Here is an example:</p> - -<code> -public function _output($output)<br /> -{<br /> - echo $output;<br /> -}</code> - -<p class="important">Please note that your <dfn>_output()</dfn> function will receive the data in its finalized state. Benchmark and memory usage data will be rendered, -cache files written (if you have caching enabled), and headers will be sent (if you use that <a href="../libraries/output.html">feature</a>) -before it is handed off to the _output() function.<br /> -<br /> -To have your controller's output cached properly, its <dfn>_output()</dfn> method can use:<br /> - -<code>if ($this->output->cache_expiration > 0)<br /> -{<br /> - $this->output->_write_cache($output);<br /> -}</code> - -If you are using this feature the page execution timer and memory usage stats might not be perfectly accurate -since they will not take into acccount any further processing you do. For an alternate way to control output <em>before</em> any of the final processing is done, please see -the available methods in the <a href="../libraries/output.html">Output Class</a>.</p> - -<a name="private"></a> -<h2>Private Functions</h2> - - -<p>In some cases you may want certain functions hidden from public access. To make a function private, simply add an -underscore as the name prefix and it will not be served via a URL request. For example, if you were to have a function like this:</p> - -<code> -private function _utility()<br /> -{<br /> - // some code<br /> -}</code> - -<p>Trying to access it via the URL, like this, will not work:</p> - -<code>example.com/index.php/<var>blog</var>/<samp>_utility</samp>/</code> - - - -<a name="subfolders"></a> -<h2>Organizing Your Controllers into Sub-folders</h2> - -<p>If you are building a large application you might find it convenient to organize your controllers into sub-folders. CodeIgniter permits you to do this.</p> - -<p>Simply create folders within your <dfn>application/controllers</dfn> directory and place your controller classes within them.</p> - -<p><strong>Note:</strong> When using this feature the first segment of your URI must specify the folder. For example, lets say you have a controller -located here:</p> - -<code>application/controllers/<kbd>products</kbd>/shoes.php</code> - -<p>To call the above controller your URI will look something like this:</p> - -<code>example.com/index.php/products/shoes/show/123</code> - -<p>Each of your sub-folders may contain a default controller which will be -called if the URL contains only the sub-folder. Simply name your default controller as specified in your -<dfn>application/config/routes.php</dfn> file</p> - - -<p>CodeIgniter also permits you to remap your URIs using its <a href="routing.html">URI Routing</a> feature.</p> - - -<h2><a name="constructors"></a>Class Constructors</h2> - - -<p>If you intend to use a constructor in any of your Controllers, you <strong>MUST</strong> place the following line of code in it:</p> - -<code>parent::__construct();</code> - -<p>The reason this line is necessary is because your local constructor will be overriding the one in the parent controller class so we need to manually call it.</p> - -<code> -<?php<br /> -class <kbd>Blog</kbd> extends CI_Controller {<br /> -<br /> - public function <kbd>__construct()</kbd><br /> - {<br /> - <var>parent::__construct();</var><br /> - // Your own constructor code<br /> - }<br /> -}<br /> -?></code> - -<p>Constructors are useful if you need to set some default values, or run a default process when your class is instantiated. -Constructors can't return a value, but they can do some default work.</p> - -<a name="reserved"></a> -<h2>Reserved Function Names</h2> - -<p>Since your controller classes will extend the main application controller you -must be careful not to name your functions identically to the ones used by that class, otherwise your local functions -will override them. See <a href="reserved_names.html">Reserved Names</a> for a full list.</p> - -<h2>That's it!</h2> - -<p>That, in a nutshell, is all there is to know about controllers.</p> - - - -</div> -<!-- END CONTENT --> - - -<div id="footer"> -<p> -Previous Topic: <a href="urls.html">CodeIgniter URLs</a> - · -<a href="#top">Top of Page</a> · -<a href="../index.html">User Guide Home</a> · -Next Topic: <a href="reserved_names.html">Reserved Names</a></p> -<p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2006 - 2011 · <a href="http://ellislab.com/">EllisLab, Inc.</a></p> -</div> - -</body> -</html>
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