diff options
Diffstat (limited to 'user_guide/general/hooks.html')
| -rw-r--r-- | user_guide/general/hooks.html | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/user_guide/general/hooks.html b/user_guide/general/hooks.html new file mode 100644 index 000000000..301654653 --- /dev/null +++ b/user_guide/general/hooks.html @@ -0,0 +1,184 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
+<html>
+<head>
+
+<title>Code Igniter 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="../scripts/nav.js"></script>
+<script type="text/javascript" src="../scripts/prototype.lite.js"></script>
+<script type="text/javascript" src="../scripts/moo.fx.js"></script>
+<script type="text/javascript">
+window.onload = function() {
+ myHeight = new fx.Height('nav', {duration: 400});
+ myHeight.hide();
+}
+</script>
+
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
+<meta http-equiv='expires' content='-1' />
+<meta http-equiv= 'pragma' content='no-cache' />
+<meta name='robots' content='all' />
+<meta name='author' content='Rick Ellis' />
+<meta name='description' content='Code Igniter 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.jpg" width="153" height="44" 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>Code Igniter User Guide Version 1.4.0</h1></td>
+<td id="breadcrumb_right"><a href="../toc.html">Full Table of Contents</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://www.codeigniter.com/">Code Igniter Home</a> ›
+<a href="../index.html">User Guide Home</a> ›
+Hooks - Extending the Framework Core
+</td>
+<td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="www.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>Hooks - Extending the Framework Core</h1>
+
+<p>Code Igniter's Hooks feature provides a means to tap into and modify the inner workings of the framework without hacking the core files.
+When Code Igniter runs it follows a specific execution process, diagramed in the <a href="../overview/appflow.html">Application Flow</a> page.
+There may be instances, however, where you'd like to cause some action to take place at a particular stage in the execution process.
+For example, you might want to run a script right before your controllers get loaded, or right after, or you might want to trigger one of
+your own scripts in some other location.
+</p>
+
+
+<h2>Defining a Hook</h2>
+
+<p>Hooks are defined in <dfn>application/config/hooks.php</dfn> file. Each hook is specified as an array with this prototype:</p>
+
+<code>
+$hook['pre_controller'] = array(<br />
+ 'class' => 'MyClass',<br />
+ 'function' => 'Myfunction',<br />
+ 'filename' => 'Myclass.php',<br />
+ 'filepath' => 'hooks',<br />
+ 'params' => array('beer', 'wine', 'snacks')<br />
+ );</code>
+
+<p><strong>Notes:</strong><br />The array index correlates to the name of the particular hook point you want to
+use. In the above example the hook point is <kbd>pre_controller</kbd>. A list of hook points is found below.
+The following items should be defined in your associative hook array:</p>
+
+<ul>
+<li><strong>class</strong> The name of the class you wish to invoke. If you prefer to use a procedural function instead of a class, leave this item blank.</li>
+<li><strong>function</strong> The function name you wish to call.</li>
+<li><strong>filename</strong> The file name containing your class/function.</li>
+<li><strong>filepath</strong> The name of the directory containing your script. Note: Your script must be located in a directory INSIDE your <kbd>application</kbd> folder, so the file path is relative to that folder. For example, if your script is located in <dfn>application/hooks</dfn>, you will simply use <samp>hooks</samp> as your filepath. If your script is located in <dfn>application/hooks/utilities</dfn> you will use <samp>hooks/utilities</samp> as your filepath. No trailing slash.</li>
+<li><strong>params</strong> Any parameters you wish to pass to your script. This item is optional.</li>
+</ul>
+
+
+<h2>Multiple Calls to the Same Hook</h2>
+
+<p>If want to use the same hook point with more then one script, simply make your array declaration multi-dimensional, like this:
+
+<code>
+$hook['pre_controller']<kbd>[]</kbd> = array(<br />
+ 'class' => 'MyClass',<br />
+ 'function' => 'Myfunction',<br />
+ 'filename' => 'Myclass.php',<br />
+ 'filepath' => 'hooks',<br />
+ 'params' => array('beer', 'wine', 'snacks')<br />
+ );<br />
+<br />
+$hook['pre_controller']<kbd>[]</kbd> = array(<br />
+ 'class' => 'MyOtherClass',<br />
+ 'function' => 'MyOtherfunction',<br />
+ 'filename' => 'Myotherclass.php',<br />
+ 'filepath' => 'hooks',<br />
+ 'params' => array('red', 'yellow', 'blue')<br />
+ );</code>
+
+<p>Notice the brackets after each array index:</p>
+
+<code>$hook['pre_controller']<kbd>[]</kbd></code>
+
+<p>This permits you to the same hook point with multiple scripts. The order you define your array will be the execution order.</p>
+
+
+<h2>Hook Points</h2>
+
+The following is a list of available hook points.</p>
+
+<ul>
+
+<li><strong>pre_system</strong><br />
+Called very early during system execution. Only the benchmark and hooks class have been loaded at this point. No routing or other processes have happened.</li>
+
+<li><strong>pre_controller</strong><br />
+Called immediately prior to any of your controllers being called. All base classes, routing, and security checks have been done.</li>
+
+<li><strong>post_controller</strong><br />
+Called immediately after the controller is called.</li>
+
+<li><strong>display_override</strong><br />
+Overrides the <dfn>_display()</dfn> function, used to send the finalized page to the web browser at the end of system execution. This permits you to
+use your own display methodology. Note that the finalized data will be available by calling <dfn>$this->output->get_output()</dfn></li>
+
+<li><strong>cache_override</strong><br />
+Enables you to call your own function instead of the <dfn>_display_cache()</dfn> function in the output class. This permits you to use your own cache display mechanism.</li>
+
+<li><strong>scaffolding_override</strong><br />
+Permits a scaffolding request to trigger your own script instead.</li>
+
+<li><strong>post_system</strong><br />
+Called after the final rendered page is sent to the browser, at the end of system execution after the finalized data is sent to the browser.</li>
+
+
+</ul>
+
+
+
+
+
+
+
+
+
+
+
+</div>
+<!-- END CONTENT -->
+
+
+<div id="footer">
+<p>
+Previous Topic: <a href="autoloader.html">Auto-loading Resources</a>
+ ·
+<a href="#top">Top of Page</a> ·
+<a href="../index.html">User Guide Home</a> ·
+Next Topic: <a href="scaffolding.html">Scaffolding</a>
+<p>
+<p><a href="http://www.codeigniter.com">Code Igniter</a> · Copyright © 2006 · <a href="http://www.pmachine.com">pMachine, Inc.</a></p>
+</div>
+
+</body>
+</html>
\ No newline at end of file |