├── README.md
└── gwp_widget_cache.php


/README.md:
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1 | GWP-Widget-Cache
2 | ================
3 | 
4 | A plugin to cache WordPress Widgets using the Transients API, based on this tutorial http://generatewp.com/?p=10132
5 | 


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/gwp_widget_cache.php:
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  1 | <?php
  2 | /*
  3 | Plugin Name: GWP Widget Cache (Cached!)
  4 | Plugin URI:
  5 | Description: A plugin to cache WordPress Widgets using the Transients API, based on this tutorial http://generatewp.com/?p=10132
  6 | Version: 1.1
  7 | Author: Ohad Raz
  8 | Author URI: http://generatewp.com
  9 | /**
 10 | * GWP_Widget_cache
 11 | */
 12 | class GWP_Widget_cache{
 13 |     /**
 14 |      * $cache_time
 15 |      * transient exiration time
 16 |      * @var int
 17 |      */
 18 |     public $cache_time = 43200; // 12 hours in seconds
 19 |      
 20 |     /**
 21 |      * __construct
 22 |      *
 23 |      * Class constructor where we will call our filter and action hooks.
 24 |      */
 25 |     function __construct(){
 26 |         add_filter( 'widget_display_callback', array($this,'_cache_widget_output'), 10, 3 );
 27 |         add_action('in_widget_form', array($this,'in_widget_form'),5,3);
 28 |         add_filter('widget_update_callback', array($this,'widget_update_callback'),5,3);
 29 |     }
 30 |      
 31 |     /**
 32 |      * get_widget_key
 33 |      *
 34 |      * Simple function to generate a unique id for the widget transient
 35 |      * based on the widget's instance and arguments
 36 |      *
 37 |      * @param  array $i widget instance
 38 |      * @param  array $a widget arguments
 39 |      * @return string md5 hash
 40 |      */
 41 |     function get_widget_key($i,$a){
 42 |         return 'WC-' . md5( serialize( array( $i, $a ) ) );
 43 |     }
 44 |  
 45 |     /**
 46 |      * _cache_widget_output
 47 |      * @param array     $instance The current widget instance's settings.
 48 |      * @param WP_Widget $widget     The current widget instance.
 49 |      * @param array     $args     An array of default widget arguments.
 50 |      * @return mixed array|boolean
 51 |      */
 52 |     function _cache_widget_output($instance, $widget, $args){
 53 |         if ( false === $instance )
 54 |             return $instance;
 55 |         
 56 |         //skip cache on preview
 57 |         if ( $widget->is_preview() ){
 58 |             return $instance;
 59 |         }
 60 |         //check if we need to cache this widget?
 61 |         if(isset($instance['wc_cache']) && $instance['wc_cache'] == true)
 62 |             return $instance;
 63 |  
 64 |         //simple timer to clock the widget rendring
 65 |         $timer_start = microtime(true);
 66 |          
 67 |         //create a uniqe transient ID for this widget instance
 68 |         $transient_name = $this->get_widget_key($instance,$args);
 69 |  
 70 |         //get the "cached version of the widget"
 71 |         if ( false === ( $cached_widget = get_transient( $transient_name ) ) ){
 72 |             // It wasn't there, so render the widget and save it as a transient
 73 |             // start a buffer to capture the widget output
 74 |             ob_start();
 75 |             //this renders the widget
 76 |             $widget->widget( $args, $instance );
 77 |             //get rendered widget from buffer
 78 |             $cached_widget = ob_get_clean();
 79 |             //save/cache the widget output as a transient
 80 |             set_transient( $transient_name, $cached_widget, $this->cache_time);
 81 |         }
 82 |  
 83 |         //output the widget
 84 |         echo $cached_widget;
 85 |         //output rendering time as an html comment
 86 |         echo '<!-- From widget cache in '.number_format( microtime(true) - $timer_start, 5 ).' seconds -->';
 87 |  
 88 |         //after the widget was rendered and printed we return false to short-circuit the normal display of the widget
 89 |         return false;  
 90 |     }
 91 |  
 92 |     /**
 93 |      * in_widget_form
 94 |      * this method displays a checkbox in the widget panel
 95 |      *
 96 |      * @param WP_Widget $t     The widget instance, passed by reference.
 97 |      * @param null      $return   Return null if new fields are added.
 98 |      * @param array     $instance An array of the widget's settings.
 99 |      *
100 |      */
101 |     function in_widget_form($t,$return,$instance){
102 |         $instance = wp_parse_args(
103 |             (array) $instance,
104 |             array(
105 |                 'title' => '',
106 |                 'text' => '',
107 |                 'wc_cache' => null
108 |             )
109 |         );
110 |  
111 |         if ( !isset($instance['wc_cache']) )
112 |             $instance['wc_cache'] = null;
113 |         ?>
114 |         <p>
115 |             <input id="<?php echo $t->get_field_id('wc_cache'); ?>" name="<?php echo $t->get_field_name('wc_cache'); ?>" type="checkbox" <?php checked(isset($instance['wc_cache']) ? $instance['wc_cache'] : 0); ?> />
116 |             <label for="<?php echo $t->get_field_id('wc_cache'); ?>"><?php _e('don\'t cache this widget?'); ?></label>
117 |         </p>
118 |         <?php
119 |     }
120 |  
121 |     /**
122 |      * widget_update_callback
123 |      * @param array     $instance     The current widget instance's settings.
124 |      * @param array     $new_instance Array of new widget settings.
125 |      * @param array     $old_instance Array of old widget settings.
126 |      * @return array    $instance
127 |      */
128 |     function widget_update_callback($instance, $new_instance, $old_instance){
129 |         //save the checkbox if its set
130 |         $instance['wc_cache'] = isset($new_instance['wc_cache']);
131 |         return $instance;
132 |     }
133 | }//end GWP_Widget_cache class
134 |  
135 |  
136 | //initiate the class
137 | add_action( 'plugins_loaded', 'GWP_Widget_cache_init' );
138 | function GWP_Widget_cache_init() {
139 |     $GLOBALS['GWP_Widget_cache'] = new GWP_Widget_cache();
140 | }
141 | 


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