summaryrefslogtreecommitdiffstats
path: root/user_guide/general/controllers.html
diff options
context:
space:
mode:
authorDerek Allard <derek.allard@ellislab.com>2008-11-13 23:59:24 +0100
committerDerek Allard <derek.allard@ellislab.com>2008-11-13 23:59:24 +0100
commit2067d1a727e7eb5e5ffb40e967f3d1fc4c8a41b2 (patch)
treea95e01024205837e9580757350d04b233e82503f /user_guide/general/controllers.html
parentdd9f932556d3cd45a1d06cc478f40d06b7649a69 (diff)
Changing EOL style to LF
Diffstat (limited to 'user_guide/general/controllers.html')
-rw-r--r--user_guide/general/controllers.html768
1 files changed, 384 insertions, 384 deletions
diff --git a/user_guide/general/controllers.html b/user_guide/general/controllers.html
index cb7f80eac..f11d09215 100644
--- a/user_guide/general/controllers.html
+++ b/user_guide/general/controllers.html
@@ -1,385 +1,385 @@
-<!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 1.7</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> &nbsp;&#8250;&nbsp;
-<a href="../index.html">User Guide Home</a> &nbsp;&#8250;&nbsp;
-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&nbsp; <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" />&nbsp;<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:&nbsp; 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 Controller {
-
- 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>&lt;?php<br />
-class <var>Blog</var> extends Controller {<br />
-<br />
-}<br />
-?&gt;</code>
-
-<p>This is <strong>not</strong> valid:</p>
-
-<code>&lt;?php<br />
-class <var>blog</var> extends Controller {<br />
-<br />
-}<br />
-?&gt;</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 Controller {
-
- function index()
- {
- echo 'Hello World!';
- }
-
- 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>
-&lt;?php<br />
-class Products extends Controller {<br />
-<br />
-&nbsp;&nbsp;&nbsp;&nbsp;function shoes($sandals, $id)<br />
-&nbsp;&nbsp;&nbsp;&nbsp;{<br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo $sandals;<br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo $id;<br />
-&nbsp;&nbsp;&nbsp;&nbsp;}<br />
-}<br />
-?&gt;
-</code>
-
-<p class="important"><strong>Important:</strong>&nbsp; If you are using the <a href="routing.html">URI Routing</a> feature, the segments
-passed to your function will be the re-routed ones.</p>
-
-
-<a name="default"></a>
-<h2>Defining a Default Controller</h2>
-
-<p>CodeIgniter can be told to load a default controller when a URI is not present,
-as will be the case when only your site root URL is requested. To specify a default controller, open
-your <dfn>application/config/routes.php</dfn> file and set this variable:</p>
-
-<code>$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>function _remap()<br />
-{<br />
-&nbsp;&nbsp;&nbsp;&nbsp;// Some code here...<br />
-}</code>
-
-<p class="important"><strong>Important:</strong>&nbsp; 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 the <kbd>_remap()</kbd> function:</p>
-
-<code>function _remap(<var>$method</var>)<br />
-{<br />
-&nbsp;&nbsp;&nbsp;&nbsp;if ($method == 'some_method')<br />
-&nbsp;&nbsp;&nbsp;&nbsp;{<br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$this->$method();<br />
-&nbsp;&nbsp;&nbsp;&nbsp;}<br />
-&nbsp;&nbsp;&nbsp;&nbsp;else<br />
-&nbsp;&nbsp;&nbsp;&nbsp;{<br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$this->default_method();<br />
-&nbsp;&nbsp;&nbsp;&nbsp;}<br />
-}</code>
-
-
-
-
-
-<a name="output"></a>
-<h2>Processing Output</h2>
-
-<p>CodeIgniter has an output class that takes care of sending your final rendered data to the web browser automatically. More information on this can be found in the
-<a href="views.html">Views</a> and <a href="../libraries/output.html">Output class</a> pages. In some cases, however, you might want to
-post-process the finalized data in some way and send it to the browser yourself. CodeIgniter permits you to
-add a function named <dfn>_output()</dfn> to your controller that will receive the finalized output data.</p>
-
-<p><strong>Important:</strong>&nbsp; If your controller contains a function named <kbd>_output()</kbd>, it will <strong>always</strong>
-be called by the output class instead of echoing the finalized data directly. The first parameter of the function will contain the finalized output.</p>
-
-<p>Here is an example:</p>
-
-<code>
-function _output($output)<br />
-{<br />
-&nbsp;&nbsp;&nbsp;&nbsp;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. 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>
-function _utility()<br />
-{<br />
-&nbsp;&nbsp;// 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>&nbsp; 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::Controller();</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>
-
-
-<p>If you are not familiar with constructors, in PHP 4, a <em>constructor</em> is simply a function that has the exact same name as the class:</p>
-
-<code>
-&lt;?php<br />
-class <kbd>Blog</kbd> extends Controller {<br />
-<br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;function <kbd>Blog()</kbd><br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{<br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<var>parent::Controller();</var><br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />
-}<br />
-?&gt;</code>
-
-<p>In PHP 5, constructors use the following syntax:</p>
-
-<code>
-&lt;?php<br />
-class <kbd>Blog</kbd> extends Controller {<br />
-<br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;function <kbd>__construct()</kbd><br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{<br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<var>parent::Controller();</var><br />
-&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />
-}<br />
-?&gt;</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:&nbsp;&nbsp;<a href="urls.html">CodeIgniter URLs</a>
-&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
-<a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
-<a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
-Next Topic:&nbsp;&nbsp;<a href="reserved_names.html">Reserved Names</a></p>
-<p><a href="http://codeigniter.com">CodeIgniter</a> &nbsp;&middot;&nbsp; Copyright &#169; 2006-2008 &nbsp;&middot;&nbsp; <a href="http://ellislab.com/">Ellislab, Inc.</a></p>
-</div>
-
-</body>
+<!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 1.7</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> &nbsp;&#8250;&nbsp;
+<a href="../index.html">User Guide Home</a> &nbsp;&#8250;&nbsp;
+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&nbsp; <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" />&nbsp;<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:&nbsp; 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 Controller {
+
+ 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>&lt;?php<br />
+class <var>Blog</var> extends Controller {<br />
+<br />
+}<br />
+?&gt;</code>
+
+<p>This is <strong>not</strong> valid:</p>
+
+<code>&lt;?php<br />
+class <var>blog</var> extends Controller {<br />
+<br />
+}<br />
+?&gt;</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 Controller {
+
+ function index()
+ {
+ echo 'Hello World!';
+ }
+
+ 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>
+&lt;?php<br />
+class Products extends Controller {<br />
+<br />
+&nbsp;&nbsp;&nbsp;&nbsp;function shoes($sandals, $id)<br />
+&nbsp;&nbsp;&nbsp;&nbsp;{<br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo $sandals;<br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;echo $id;<br />
+&nbsp;&nbsp;&nbsp;&nbsp;}<br />
+}<br />
+?&gt;
+</code>
+
+<p class="important"><strong>Important:</strong>&nbsp; If you are using the <a href="routing.html">URI Routing</a> feature, the segments
+passed to your function will be the re-routed ones.</p>
+
+
+<a name="default"></a>
+<h2>Defining a Default Controller</h2>
+
+<p>CodeIgniter can be told to load a default controller when a URI is not present,
+as will be the case when only your site root URL is requested. To specify a default controller, open
+your <dfn>application/config/routes.php</dfn> file and set this variable:</p>
+
+<code>$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>function _remap()<br />
+{<br />
+&nbsp;&nbsp;&nbsp;&nbsp;// Some code here...<br />
+}</code>
+
+<p class="important"><strong>Important:</strong>&nbsp; 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 the <kbd>_remap()</kbd> function:</p>
+
+<code>function _remap(<var>$method</var>)<br />
+{<br />
+&nbsp;&nbsp;&nbsp;&nbsp;if ($method == 'some_method')<br />
+&nbsp;&nbsp;&nbsp;&nbsp;{<br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$this->$method();<br />
+&nbsp;&nbsp;&nbsp;&nbsp;}<br />
+&nbsp;&nbsp;&nbsp;&nbsp;else<br />
+&nbsp;&nbsp;&nbsp;&nbsp;{<br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$this->default_method();<br />
+&nbsp;&nbsp;&nbsp;&nbsp;}<br />
+}</code>
+
+
+
+
+
+<a name="output"></a>
+<h2>Processing Output</h2>
+
+<p>CodeIgniter has an output class that takes care of sending your final rendered data to the web browser automatically. More information on this can be found in the
+<a href="views.html">Views</a> and <a href="../libraries/output.html">Output class</a> pages. In some cases, however, you might want to
+post-process the finalized data in some way and send it to the browser yourself. CodeIgniter permits you to
+add a function named <dfn>_output()</dfn> to your controller that will receive the finalized output data.</p>
+
+<p><strong>Important:</strong>&nbsp; If your controller contains a function named <kbd>_output()</kbd>, it will <strong>always</strong>
+be called by the output class instead of echoing the finalized data directly. The first parameter of the function will contain the finalized output.</p>
+
+<p>Here is an example:</p>
+
+<code>
+function _output($output)<br />
+{<br />
+&nbsp;&nbsp;&nbsp;&nbsp;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. 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>
+function _utility()<br />
+{<br />
+&nbsp;&nbsp;// 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>&nbsp; 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::Controller();</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>
+
+
+<p>If you are not familiar with constructors, in PHP 4, a <em>constructor</em> is simply a function that has the exact same name as the class:</p>
+
+<code>
+&lt;?php<br />
+class <kbd>Blog</kbd> extends Controller {<br />
+<br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;function <kbd>Blog()</kbd><br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{<br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<var>parent::Controller();</var><br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />
+}<br />
+?&gt;</code>
+
+<p>In PHP 5, constructors use the following syntax:</p>
+
+<code>
+&lt;?php<br />
+class <kbd>Blog</kbd> extends Controller {<br />
+<br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;function <kbd>__construct()</kbd><br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;{<br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<var>parent::Controller();</var><br />
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br />
+}<br />
+?&gt;</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:&nbsp;&nbsp;<a href="urls.html">CodeIgniter URLs</a>
+&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
+<a href="#top">Top of Page</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
+<a href="../index.html">User Guide Home</a>&nbsp;&nbsp;&nbsp;&middot;&nbsp;&nbsp;
+Next Topic:&nbsp;&nbsp;<a href="reserved_names.html">Reserved Names</a></p>
+<p><a href="http://codeigniter.com">CodeIgniter</a> &nbsp;&middot;&nbsp; Copyright &#169; 2006-2008 &nbsp;&middot;&nbsp; <a href="http://ellislab.com/">Ellislab, Inc.</a></p>
+</div>
+
+</body>
</html> \ No newline at end of file