caching.html 37 KB

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  82. <li class="toctree-l2"><a class="reference internal" href="errors.html">Error Handling</a></li>
  83. <li class="toctree-l2 current"><a class="current reference internal" href="#">Caching</a></li>
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  97. <li class="toctree-l2"><a class="reference internal" href="../libraries/caching.html">Caching Driver</a></li>
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  125. <li class="toctree-l2"><a class="reference internal" href="../libraries/zip.html">Zip Encoding Class</a></li>
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  135. <li class="toctree-l2"><a class="reference internal" href="../database/results.html">Generating Query Results</a></li>
  136. <li class="toctree-l2"><a class="reference internal" href="../database/helpers.html">Query Helper Functions</a></li>
  137. <li class="toctree-l2"><a class="reference internal" href="../database/query_builder.html">Query Builder Class</a></li>
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  141. <li class="toctree-l2"><a class="reference internal" href="../database/caching.html">Query Caching</a></li>
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  145. </ul>
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  148. <ul>
  149. <li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
  150. <li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
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  193. </div>
  194. <div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
  195. <ul>
  196. <li class="toctree-l1"><a class="reference internal" href="welcome.html">Welcome to CodeIgniter</a></li>
  197. </ul>
  198. <ul>
  199. <li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation Instructions</a><ul>
  200. <li class="toctree-l2"><a class="reference internal" href="../installation/downloads.html">Downloading CodeIgniter</a></li>
  201. <li class="toctree-l2"><a class="reference internal" href="../installation/index.html">Installation Instructions</a></li>
  202. <li class="toctree-l2"><a class="reference internal" href="../installation/upgrading.html">Upgrading From a Previous Version</a></li>
  203. <li class="toctree-l2"><a class="reference internal" href="../installation/troubleshooting.html">Troubleshooting</a></li>
  204. </ul>
  205. </li>
  206. </ul>
  207. <ul>
  208. <li class="toctree-l1"><a class="reference internal" href="../overview/index.html">CodeIgniter Overview</a><ul>
  209. <li class="toctree-l2"><a class="reference internal" href="../overview/getting_started.html">Getting Started</a></li>
  210. <li class="toctree-l2"><a class="reference internal" href="../overview/at_a_glance.html">CodeIgniter at a Glance</a></li>
  211. <li class="toctree-l2"><a class="reference internal" href="../overview/features.html">Supported Features</a></li>
  212. <li class="toctree-l2"><a class="reference internal" href="../overview/appflow.html">Application Flow Chart</a></li>
  213. <li class="toctree-l2"><a class="reference internal" href="../overview/mvc.html">Model-View-Controller</a></li>
  214. <li class="toctree-l2"><a class="reference internal" href="../overview/goals.html">Architectural Goals</a></li>
  215. </ul>
  216. </li>
  217. </ul>
  218. <ul>
  219. <li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Tutorial</a><ul>
  220. <li class="toctree-l2"><a class="reference internal" href="../tutorial/static_pages.html">Static pages</a></li>
  221. <li class="toctree-l2"><a class="reference internal" href="../tutorial/news_section.html">News section</a></li>
  222. <li class="toctree-l2"><a class="reference internal" href="../tutorial/create_news_items.html">Create news items</a></li>
  223. <li class="toctree-l2"><a class="reference internal" href="../tutorial/conclusion.html">Conclusion</a></li>
  224. </ul>
  225. </li>
  226. </ul>
  227. <ul>
  228. <li class="toctree-l1"><a class="reference internal" href="../contributing/index.html">Contributing to CodeIgniter</a><ul>
  229. <li class="toctree-l2"><a class="reference internal" href="../documentation/index.html">Writing CodeIgniter Documentation</a></li>
  230. <li class="toctree-l2"><a class="reference internal" href="../DCO.html">Developer’s Certificate of Origin 1.1</a></li>
  231. </ul>
  232. </li>
  233. </ul>
  234. <ul class="current">
  235. <li class="toctree-l1 current"><a class="reference internal" href="index.html">General Topics</a><ul class="current">
  236. <li class="toctree-l2"><a class="reference internal" href="urls.html">CodeIgniter URLs</a></li>
  237. <li class="toctree-l2"><a class="reference internal" href="controllers.html">Controllers</a></li>
  238. <li class="toctree-l2"><a class="reference internal" href="reserved_names.html">Reserved Names</a></li>
  239. <li class="toctree-l2"><a class="reference internal" href="views.html">Views</a></li>
  240. <li class="toctree-l2"><a class="reference internal" href="models.html">Models</a></li>
  241. <li class="toctree-l2"><a class="reference internal" href="helpers.html">Helpers</a></li>
  242. <li class="toctree-l2"><a class="reference internal" href="libraries.html">Using CodeIgniter Libraries</a></li>
  243. <li class="toctree-l2"><a class="reference internal" href="creating_libraries.html">Creating Libraries</a></li>
  244. <li class="toctree-l2"><a class="reference internal" href="drivers.html">Using CodeIgniter Drivers</a></li>
  245. <li class="toctree-l2"><a class="reference internal" href="creating_drivers.html">Creating Drivers</a></li>
  246. <li class="toctree-l2"><a class="reference internal" href="core_classes.html">Creating Core System Classes</a></li>
  247. <li class="toctree-l2"><a class="reference internal" href="ancillary_classes.html">Creating Ancillary Classes</a></li>
  248. <li class="toctree-l2"><a class="reference internal" href="hooks.html">Hooks - Extending the Framework Core</a></li>
  249. <li class="toctree-l2"><a class="reference internal" href="autoloader.html">Auto-loading Resources</a></li>
  250. <li class="toctree-l2"><a class="reference internal" href="common_functions.html">Common Functions</a></li>
  251. <li class="toctree-l2"><a class="reference internal" href="compatibility_functions.html">Compatibility Functions</a></li>
  252. <li class="toctree-l2"><a class="reference internal" href="routing.html">URI Routing</a></li>
  253. <li class="toctree-l2"><a class="reference internal" href="errors.html">Error Handling</a></li>
  254. <li class="toctree-l2 current"><a class="current reference internal" href="#">Caching</a></li>
  255. <li class="toctree-l2"><a class="reference internal" href="profiling.html">Profiling Your Application</a></li>
  256. <li class="toctree-l2"><a class="reference internal" href="cli.html">Running via the CLI</a></li>
  257. <li class="toctree-l2"><a class="reference internal" href="managing_apps.html">Managing your Applications</a></li>
  258. <li class="toctree-l2"><a class="reference internal" href="environments.html">Handling Multiple Environments</a></li>
  259. <li class="toctree-l2"><a class="reference internal" href="alternative_php.html">Alternate PHP Syntax for View Files</a></li>
  260. <li class="toctree-l2"><a class="reference internal" href="security.html">Security</a></li>
  261. <li class="toctree-l2"><a class="reference internal" href="styleguide.html">PHP Style Guide</a></li>
  262. </ul>
  263. </li>
  264. </ul>
  265. <ul>
  266. <li class="toctree-l1"><a class="reference internal" href="../libraries/index.html">Libraries</a><ul>
  267. <li class="toctree-l2"><a class="reference internal" href="../libraries/benchmark.html">Benchmarking Class</a></li>
  268. <li class="toctree-l2"><a class="reference internal" href="../libraries/caching.html">Caching Driver</a></li>
  269. <li class="toctree-l2"><a class="reference internal" href="../libraries/calendar.html">Calendaring Class</a></li>
  270. <li class="toctree-l2"><a class="reference internal" href="../libraries/cart.html">Shopping Cart Class</a></li>
  271. <li class="toctree-l2"><a class="reference internal" href="../libraries/config.html">Config Class</a></li>
  272. <li class="toctree-l2"><a class="reference internal" href="../libraries/email.html">Email Class</a></li>
  273. <li class="toctree-l2"><a class="reference internal" href="../libraries/encrypt.html">Encrypt Class</a></li>
  274. <li class="toctree-l2"><a class="reference internal" href="../libraries/encryption.html">Encryption Library</a></li>
  275. <li class="toctree-l2"><a class="reference internal" href="../libraries/file_uploading.html">File Uploading Class</a></li>
  276. <li class="toctree-l2"><a class="reference internal" href="../libraries/form_validation.html">Form Validation</a></li>
  277. <li class="toctree-l2"><a class="reference internal" href="../libraries/ftp.html">FTP Class</a></li>
  278. <li class="toctree-l2"><a class="reference internal" href="../libraries/image_lib.html">Image Manipulation Class</a></li>
  279. <li class="toctree-l2"><a class="reference internal" href="../libraries/input.html">Input Class</a></li>
  280. <li class="toctree-l2"><a class="reference internal" href="../libraries/javascript.html">Javascript Class</a></li>
  281. <li class="toctree-l2"><a class="reference internal" href="../libraries/language.html">Language Class</a></li>
  282. <li class="toctree-l2"><a class="reference internal" href="../libraries/loader.html">Loader Class</a></li>
  283. <li class="toctree-l2"><a class="reference internal" href="../libraries/migration.html">Migrations Class</a></li>
  284. <li class="toctree-l2"><a class="reference internal" href="../libraries/output.html">Output Class</a></li>
  285. <li class="toctree-l2"><a class="reference internal" href="../libraries/pagination.html">Pagination Class</a></li>
  286. <li class="toctree-l2"><a class="reference internal" href="../libraries/parser.html">Template Parser Class</a></li>
  287. <li class="toctree-l2"><a class="reference internal" href="../libraries/security.html">Security Class</a></li>
  288. <li class="toctree-l2"><a class="reference internal" href="../libraries/sessions.html">Session Library</a></li>
  289. <li class="toctree-l2"><a class="reference internal" href="../libraries/table.html">HTML Table Class</a></li>
  290. <li class="toctree-l2"><a class="reference internal" href="../libraries/trackback.html">Trackback Class</a></li>
  291. <li class="toctree-l2"><a class="reference internal" href="../libraries/typography.html">Typography Class</a></li>
  292. <li class="toctree-l2"><a class="reference internal" href="../libraries/unit_testing.html">Unit Testing Class</a></li>
  293. <li class="toctree-l2"><a class="reference internal" href="../libraries/uri.html">URI Class</a></li>
  294. <li class="toctree-l2"><a class="reference internal" href="../libraries/user_agent.html">User Agent Class</a></li>
  295. <li class="toctree-l2"><a class="reference internal" href="../libraries/xmlrpc.html">XML-RPC and XML-RPC Server Classes</a></li>
  296. <li class="toctree-l2"><a class="reference internal" href="../libraries/zip.html">Zip Encoding Class</a></li>
  297. </ul>
  298. </li>
  299. </ul>
  300. <ul>
  301. <li class="toctree-l1"><a class="reference internal" href="../database/index.html">Database Reference</a><ul>
  302. <li class="toctree-l2"><a class="reference internal" href="../database/examples.html">Quick Start: Usage Examples</a></li>
  303. <li class="toctree-l2"><a class="reference internal" href="../database/configuration.html">Database Configuration</a></li>
  304. <li class="toctree-l2"><a class="reference internal" href="../database/connecting.html">Connecting to a Database</a></li>
  305. <li class="toctree-l2"><a class="reference internal" href="../database/queries.html">Running Queries</a></li>
  306. <li class="toctree-l2"><a class="reference internal" href="../database/results.html">Generating Query Results</a></li>
  307. <li class="toctree-l2"><a class="reference internal" href="../database/helpers.html">Query Helper Functions</a></li>
  308. <li class="toctree-l2"><a class="reference internal" href="../database/query_builder.html">Query Builder Class</a></li>
  309. <li class="toctree-l2"><a class="reference internal" href="../database/transactions.html">Transactions</a></li>
  310. <li class="toctree-l2"><a class="reference internal" href="../database/metadata.html">Getting MetaData</a></li>
  311. <li class="toctree-l2"><a class="reference internal" href="../database/call_function.html">Custom Function Calls</a></li>
  312. <li class="toctree-l2"><a class="reference internal" href="../database/caching.html">Query Caching</a></li>
  313. <li class="toctree-l2"><a class="reference internal" href="../database/forge.html">Database Manipulation with Database Forge</a></li>
  314. <li class="toctree-l2"><a class="reference internal" href="../database/utilities.html">Database Utilities Class</a></li>
  315. <li class="toctree-l2"><a class="reference internal" href="../database/db_driver_reference.html">Database Driver Reference</a></li>
  316. </ul>
  317. </li>
  318. </ul>
  319. <ul>
  320. <li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
  321. <li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
  322. <li class="toctree-l2"><a class="reference internal" href="../helpers/captcha_helper.html">CAPTCHA Helper</a></li>
  323. <li class="toctree-l2"><a class="reference internal" href="../helpers/cookie_helper.html">Cookie Helper</a></li>
  324. <li class="toctree-l2"><a class="reference internal" href="../helpers/date_helper.html">Date Helper</a></li>
  325. <li class="toctree-l2"><a class="reference internal" href="../helpers/directory_helper.html">Directory Helper</a></li>
  326. <li class="toctree-l2"><a class="reference internal" href="../helpers/download_helper.html">Download Helper</a></li>
  327. <li class="toctree-l2"><a class="reference internal" href="../helpers/email_helper.html">Email Helper</a></li>
  328. <li class="toctree-l2"><a class="reference internal" href="../helpers/file_helper.html">File Helper</a></li>
  329. <li class="toctree-l2"><a class="reference internal" href="../helpers/form_helper.html">Form Helper</a></li>
  330. <li class="toctree-l2"><a class="reference internal" href="../helpers/html_helper.html">HTML Helper</a></li>
  331. <li class="toctree-l2"><a class="reference internal" href="../helpers/inflector_helper.html">Inflector Helper</a></li>
  332. <li class="toctree-l2"><a class="reference internal" href="../helpers/language_helper.html">Language Helper</a></li>
  333. <li class="toctree-l2"><a class="reference internal" href="../helpers/number_helper.html">Number Helper</a></li>
  334. <li class="toctree-l2"><a class="reference internal" href="../helpers/path_helper.html">Path Helper</a></li>
  335. <li class="toctree-l2"><a class="reference internal" href="../helpers/security_helper.html">Security Helper</a></li>
  336. <li class="toctree-l2"><a class="reference internal" href="../helpers/smiley_helper.html">Smiley Helper</a></li>
  337. <li class="toctree-l2"><a class="reference internal" href="../helpers/string_helper.html">String Helper</a></li>
  338. <li class="toctree-l2"><a class="reference internal" href="../helpers/text_helper.html">Text Helper</a></li>
  339. <li class="toctree-l2"><a class="reference internal" href="../helpers/typography_helper.html">Typography Helper</a></li>
  340. <li class="toctree-l2"><a class="reference internal" href="../helpers/url_helper.html">URL Helper</a></li>
  341. <li class="toctree-l2"><a class="reference internal" href="../helpers/xml_helper.html">XML Helper</a></li>
  342. </ul>
  343. </li>
  344. </ul>
  345. </div>
  346. &nbsp;
  347. </nav>
  348. <section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
  349. <nav class="wy-nav-top" role="navigation" aria-label="top navigation">
  350. <i data-toggle="wy-nav-top" class="fa fa-bars"></i>
  351. <a href="../index.html">CodeIgniter</a>
  352. </nav>
  353. <div class="wy-nav-content">
  354. <div class="rst-content">
  355. <div role="navigation" aria-label="breadcrumbs navigation">
  356. <ul class="wy-breadcrumbs">
  357. <li><a href="../index.html">Docs</a> &raquo;</li>
  358. <li><a href="index.html">General Topics</a> &raquo;</li>
  359. <li>Web Page Caching</li>
  360. <li class="wy-breadcrumbs-aside">
  361. </li>
  362. <div style="float:right;margin-left:5px;" id="closeMe">
  363. <img title="Classic Layout" alt="classic layout" src="data:image/gif;base64,R0lGODlhFAAUAJEAAAAAADMzM////wAAACH5BAUUAAIALAAAAAAUABQAAAImlI+py+0PU5gRBRDM3DxbWoXis42X13USOLauUIqnlsaH/eY6UwAAOw==" />
  364. </div>
  365. </ul>
  366. <hr/>
  367. </div>
  368. <div role="main" class="document">
  369. <div class="section" id="web-page-caching">
  370. <h1>Web Page Caching<a class="headerlink" href="#web-page-caching" title="Permalink to this headline">¶</a></h1>
  371. <p>CodeIgniter lets you cache your pages in order to achieve maximum
  372. performance.</p>
  373. <p>Although CodeIgniter is quite fast, the amount of dynamic information
  374. you display in your pages will correlate directly to the server
  375. resources, memory, and processing cycles utilized, which affect your
  376. page load speeds. By caching your pages, since they are saved in their
  377. fully rendered state, you can achieve performance that nears that of
  378. static web pages.</p>
  379. <div class="section" id="how-does-caching-work">
  380. <h2>How Does Caching Work?<a class="headerlink" href="#how-does-caching-work" title="Permalink to this headline">¶</a></h2>
  381. <p>Caching can be enabled on a per-page basis, and you can set the length
  382. of time that a page should remain cached before being refreshed. When a
  383. page is loaded for the first time, the cache file will be written to
  384. your application/cache folder. On subsequent page loads the cache file
  385. will be retrieved and sent to the requesting user’s browser. If it has
  386. expired, it will be deleted and refreshed before being sent to the
  387. browser.</p>
  388. </div>
  389. <div class="section" id="enabling-caching">
  390. <h2>Enabling Caching<a class="headerlink" href="#enabling-caching" title="Permalink to this headline">¶</a></h2>
  391. <p>To enable caching, put the following tag in any of your controller
  392. methods:</p>
  393. <div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nv">$this</span><span class="o">-&gt;</span><span class="na">output</span><span class="o">-&gt;</span><span class="na">cache</span><span class="p">(</span><span class="nv">$n</span><span class="p">);</span>
  394. </pre></div>
  395. </div>
  396. <p>Where <code class="docutils literal"><span class="pre">$n</span></code> is the number of <strong>minutes</strong> you wish the page to remain
  397. cached between refreshes.</p>
  398. <p>The above tag can go anywhere within a method. It is not affected by
  399. the order that it appears, so place it wherever it seems most logical to
  400. you. Once the tag is in place, your pages will begin being cached.</p>
  401. <div class="admonition important">
  402. <p class="first admonition-title">Important</p>
  403. <p class="last">Because of the way CodeIgniter stores content for output,
  404. caching will only work if you are generating display for your
  405. controller with a <a class="reference internal" href="views.html"><span class="doc">view</span></a>.</p>
  406. </div>
  407. <div class="admonition important">
  408. <p class="first admonition-title">Important</p>
  409. <p class="last">If you change configuration options that might affect
  410. your output, you have to manually delete your cache files.</p>
  411. </div>
  412. <div class="admonition note">
  413. <p class="first admonition-title">Note</p>
  414. <p class="last">Before the cache files can be written you must set the file
  415. permissions on your <em>application/cache/</em> directory such that
  416. it is writable.</p>
  417. </div>
  418. </div>
  419. <div class="section" id="deleting-caches">
  420. <h2>Deleting Caches<a class="headerlink" href="#deleting-caches" title="Permalink to this headline">¶</a></h2>
  421. <p>If you no longer wish to cache a file you can remove the caching tag and
  422. it will no longer be refreshed when it expires.</p>
  423. <div class="admonition note">
  424. <p class="first admonition-title">Note</p>
  425. <p class="last">Removing the tag will not delete the cache immediately. It will
  426. have to expire normally.</p>
  427. </div>
  428. <p>If you need to manually delete the cache, you can use the <code class="docutils literal"><span class="pre">delete_cache()</span></code>
  429. method:</p>
  430. <div class="highlight-ci"><div class="highlight"><pre><span></span><span class="c1">// Deletes cache for the currently requested URI</span>
  431. <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">output</span><span class="o">-&gt;</span><span class="na">delete_cache</span><span class="p">();</span>
  432. <span class="c1">// Deletes cache for /foo/bar</span>
  433. <span class="nv">$this</span><span class="o">-&gt;</span><span class="na">output</span><span class="o">-&gt;</span><span class="na">delete_cache</span><span class="p">(</span><span class="s1">&#39;/foo/bar&#39;</span><span class="p">);</span>
  434. </pre></div>
  435. </div>
  436. </div>
  437. </div>
  438. </div>
  439. <footer>
  440. <div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
  441. <a href="profiling.html" class="btn btn-neutral float-right" title="Profiling Your Application">Next <span class="fa fa-arrow-circle-right"></span></a>
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  444. <hr/>
  445. <div role="contentinfo">
  446. <p>
  447. &copy; Copyright 2014 - 2019, British Columbia Institute of Technology.
  448. Last updated on Sep 19, 2019.
  449. </p>
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