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| author | admin <devnull@localhost> | 2006-08-25 19:25:49 +0200 |
|---|---|---|
| committer | admin <devnull@localhost> | 2006-08-25 19:25:49 +0200 |
| commit | b0dd10f8171945e0c1f3527dd1e9d18b043e01a7 (patch) | |
| tree | c3583ba09e72217683c4304f4690df6ce39ba731 /user_guide/general/hooks.html | |
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| -rw-r--r-- | user_guide/general/hooks.html | 184 |
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+<td><h1>Code Igniter User Guide Version 1.4.0</h1></td>
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+Hooks - Extending the Framework Core
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+
+<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>
+
+
+
+
+
+
+
+
+
+
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