4 * Abstract action class with scaffolding for caching HTML and other values
7 * Before using any of the caching functionality, call startCache.
8 * After the last call to either getCachedValue or addCachedHTML, call saveCache.
10 * To get a cached value or compute it, use getCachedValue like this:
11 * $this->getCachedValue( $callback );
13 * To add HTML that should be cached, use addCachedHTML like this:
14 * $this->addCachedHTML( $callback );
16 * The callback function is only called when needed, so do all your expensive
17 * computations here. This function should returns the HTML to be cached.
18 * It should not add anything to the PageOutput object!
20 * This program is free software; you can redistribute it and/or modify
21 * it under the terms of the GNU General Public License as published by
22 * the Free Software Foundation; either version 2 of the License, or
23 * (at your option) any later version.
25 * This program is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28 * GNU General Public License for more details.
30 * You should have received a copy of the GNU General Public License along
31 * with this program; if not, write to the Free Software Foundation, Inc.,
32 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
33 * http://www.gnu.org/copyleft/gpl.html
37 * @author Jeroen De Dauw < jeroendedauw@gmail.com >
40 abstract class CachedAction
extends FormlessAction
implements ICacheHelper
{
43 * CacheHelper object to which we forward the non-SpecialPage specific caching work.
44 * Initialized in startCache.
49 protected $cacheHelper;
52 * If the cache is enabled or not.
57 protected $cacheEnabled = true;
60 * Sets if the cache should be enabled or not.
63 * @param boolean $cacheEnabled
65 public function setCacheEnabled( $cacheEnabled ) {
66 $this->cacheHelper
->setCacheEnabled( $cacheEnabled );
70 * Initializes the caching.
71 * Should be called before the first time anything is added via addCachedHTML.
75 * @param integer|null $cacheExpiry Sets the cache expiry, either ttl in seconds or unix timestamp.
76 * @param boolean|null $cacheEnabled Sets if the cache should be enabled or not.
78 public function startCache( $cacheExpiry = null, $cacheEnabled = null ) {
79 $this->cacheHelper
= new CacheHelper();
81 $this->cacheHelper
->setCacheEnabled( $this->cacheEnabled
);
82 $this->cacheHelper
->setOnInitializedHandler( array( $this, 'onCacheInitialized' ) );
84 $keyArgs = $this->getCacheKey();
86 if ( array_key_exists( 'action', $keyArgs ) && $keyArgs['action'] === 'purge' ) {
87 unset( $keyArgs['action'] );
90 $this->cacheHelper
->setCacheKey( $keyArgs );
92 if ( $this->getRequest()->getText( 'action' ) === 'purge' ) {
93 $this->cacheHelper
->rebuildOnDemand();
96 $this->cacheHelper
->startCache( $cacheExpiry, $cacheEnabled );
100 * Get a cached value if available or compute it if not and then cache it if possible.
101 * The provided $computeFunction is only called when the computation needs to happen
102 * and should return a result value. $args are arguments that will be passed to the
103 * compute function when called.
107 * @param {function} $computeFunction
108 * @param array|mixed $args
109 * @param string|null $key
113 public function getCachedValue( $computeFunction, $args = array(), $key = null ) {
114 return $this->cacheHelper
->getCachedValue( $computeFunction, $args, $key );
118 * Add some HTML to be cached.
119 * This is done by providing a callback function that should
120 * return the HTML to be added. It will only be called if the
121 * item is not in the cache yet or when the cache has been invalidated.
125 * @param {function} $computeFunction
127 * @param string|null $key
129 public function addCachedHTML( $computeFunction, $args = array(), $key = null ) {
130 $this->getOutput()->addHTML( $this->cacheHelper
->getCachedValue( $computeFunction, $args, $key ) );
134 * Saves the HTML to the cache in case it got recomputed.
135 * Should be called after the last time anything is added via addCachedHTML.
139 public function saveCache() {
140 $this->cacheHelper
->saveCache();
144 * Sets the time to live for the cache, in seconds or a unix timestamp indicating the point of expiry.
148 * @param integer $cacheExpiry
150 public function setExpiry( $cacheExpiry ) {
151 $this->cacheHelper
->setExpiry( $cacheExpiry );
155 * Returns the variables used to constructed the cache key in an array.
161 protected function getCacheKey() {
163 get_class( $this->page
),
165 $this->getLanguage()->getCode()
170 * Gets called after the cache got initialized.
174 * @param boolean $hasCached
176 public function onCacheInitialized( $hasCached ) {
178 $this->getOutput()->setSubtitle( $this->cacheHelper
->getCachedNotice( $this->getContext() ) );