115 lines
		
	
	
		
			5.2 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
			
		
		
	
	
			115 lines
		
	
	
		
			5.2 KiB
		
	
	
	
		
			HTML
		
	
	
	
	
	
| <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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| <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
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| <head>
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| 
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| <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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| <title>Web Page Caching : CodeIgniter User Guide</title>
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| 
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| <style type='text/css' media='all'>@import url('../userguide.css');</style>
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| <link rel='stylesheet' type='text/css' media='all' href='../userguide.css' />
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| 
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| <script type="text/javascript" src="../nav/nav.js"></script>
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| <script type="text/javascript" src="../nav/prototype.lite.js"></script>
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| <script type="text/javascript" src="../nav/moo.fx.js"></script>
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| <script type="text/javascript" src="../nav/user_guide_menu.js"></script>
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| <meta http-equiv='expires' content='-1' />
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| <meta http-equiv= 'pragma' content='no-cache' />
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| <meta name='robots' content='all' />
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| <meta name='author' content='ExpressionEngine Dev Team' />
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| <meta name='description' content='CodeIgniter User Guide' />
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| 
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| </head>
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| <body>
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| 
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| <!-- START NAVIGATION -->
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| <div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div>
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| <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>
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| <div id="masthead">
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| <table cellpadding="0" cellspacing="0" border="0" style="width:100%">
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| <tr>
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| <td><h1>CodeIgniter User Guide Version 1.7.3</h1></td>
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| <td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td>
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| </tr>
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| </table>
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| </div>
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| <!-- END NAVIGATION -->
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| 
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| 
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| <!-- START BREADCRUMB -->
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| <table cellpadding="0" cellspacing="0" border="0" style="width:100%">
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| <tr>
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| <td id="breadcrumb">
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| <a href="http://codeigniter.com/">CodeIgniter Home</a>  › 
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| <a href="../index.html">User Guide Home</a>  › 
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| Page Caching
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| </td>
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| <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>
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| </tr>
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| </table>
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| <!-- END BREADCRUMB -->
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| 
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| <br clear="all" />
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| 
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| 
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| <!-- START CONTENT -->
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| <div id="content">
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| 
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| 
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| <h1>Web Page Caching</h1>
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| 
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| <p>CodeIgniter lets you cache your pages in order to achieve maximum performance.</p>
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| 
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| <p>Although CodeIgniter is quite fast, the amount of dynamic information you display in your pages will correlate directly to the
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| server resources, memory, and processing cycles utilized, which affect your page load speeds.
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| By caching your pages, since they are saved in their fully rendered state, you can achieve performance that nears that of static web pages.</p>
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| 
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| 
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| <h2>How Does Caching Work?</h2>
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| 
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| <p>Caching can be enabled on a per-page basis, and you can set the length of time that a page should remain cached before being refreshed.
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| When a page is loaded for the first time, the cache file will be written to your <dfn>system/cache</dfn> folder.  On subsequent page loads the cache file will be retrieved
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| and sent to the requesting user's browser.  If it has expired, it will be deleted and refreshed before being sent to the browser.</p>
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| 
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| <p>Note: The Benchmark tag is not cached so you can still view your page load speed when caching is enabled.</p>
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| 
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| <h2>Enabling Caching</h2>
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| 
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| <p>To enable caching, put the following tag in any of your controller functions:</p>
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| 
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| <code>$this->output->cache(<var>n</var>);</code>
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| 
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| <p>Where <var>n</var> is the number of <strong>minutes</strong> you wish the page to remain cached between refreshes.</p>
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| 
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| <p>The above tag can go anywhere within a function. It is not affected by the order that it appears, so place it wherever it seems
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| most logical to you. Once the tag is in place, your pages will begin being cached.</p>
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| 
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| <p class="important"><strong>Warning:</strong> Because of the way CodeIgniter stores content for output, caching will only work if you are generating display for your controller with a <a href="./views.html">view</a>.</p>
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| <p class="important"><strong>Note:</strong> Before the cache files can be written you must set the file permissions on your
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| <dfn>system/cache</dfn> folder such that it is writable.</p>
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| 
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| <h2>Deleting Caches</h2>
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| 
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| <p>If you no longer wish to cache a file you can remove the caching tag and it will no longer be refreshed when it expires.  Note:
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| Removing the tag will not delete the cache immediately.  It will have to expire normally.  If you need to remove it earlier you
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| will need to manually delete it from your cache folder.</p>
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| 
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| 
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| 
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| </div>
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| <!-- END CONTENT -->
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| 
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| 
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| <div id="footer">
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| <p>
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| Previous Topic:  <a href="errors.html">Error Handling</a>
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|    ·  
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| <a href="#top">Top of Page</a>   ·  
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| <a href="../index.html">User Guide Home</a>   ·  
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| Next Topic:  <a href="profiling.html">Profiling Your Application</a>
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| </p>
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| <p><a href="http://codeigniter.com">CodeIgniter</a>  ·  Copyright © 2006-2010  ·  <a href="http://ellislab.com/">Ellislab, Inc.</a></p>
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| </div>
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| 
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| </body>
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| </html> |