Ticket #10190: plugin-dependency.php

<?php
/**
 * This is the API for dependency checking for plugins and themes. This way plugins/themes can use this API
 * to check to see if something is loaded or not. If its loaded and the right version
 * passes muster as well, the API will return true.
 * 
 * By default all plugins that are in the plugins list (active or inactive) are regiestered and
 * this API will help plugins/themes detirmine if they can run if it meets the requirements.
 *
 * @package WordPress
 * @subpackage Plugin Dependency
 * @since 2.9
 */

class WP_Plugin_Dependency {
        
        var $item_array = array();
        
        var $item_defaults = array('required' => true, 'oper' => '>=' );
                
        // Public Functions
        /**
         * 
         * @return 
         * @param object $item_id
         */
        function is_activated($item_id) {
                if ($this->item_array[$item_id]['settings']['activated'])
                        return true;
                        
                return false;
        }

        /**
         * 
         * @return 
         * @param object $item_id
         */
        function activate($item_id) {
                global $wp_version;
                
                if (!$this->check($item_id))
                        return false;           
                
                // Add "Activate" to the plugins "setting" array.
                $item_settings = $this->item_array[$item_id]['settings'];
                $act = array('activated' => true);
                
                $this->item_array[$item_id]['settings'] = array_merge($item_settings, $act);
                
                return true;
        }

        /**
         * 
         * @return 
         * @param object $item_id
         */
        function check($item_id) {
                global $wp_version;
                
                $item = $this->_get_item_data($item_id);        //      the name just very sanitized
                
                if (!$item)
                        return false;   //      plugin does not exist. FAIL!
                
                $setting = array();
                $wordpress = array();
                $item_dep = array();
                foreach ($item as $item_data => $data) {
                        
                        if ($item_data == 'settings')
                                $setting = $data;
                        if ($item_data == 'wordpress')
                                $wordpress = $data;
                        if ($item_data == 'plugins')
                                $item_dep = $data;
                }

                // version needed to run this plugin is passed through this function
                // @todo: Merge WordPress Defaults in-case there are none in the plugin check.
                if (!$this->_wordpress_version_check($wordpress['version'], $wordpress['oper']))
                        return false;   //      plugin can not run since the WordPress version does not work.

                //      no plugin dependinces. As long as the WordPress 
                //      version is up-to-date, we can use this plugin/theme!
                if (!is_array($item_dep))
                        return true;
                
                foreach ($item_dep as $plugin => $data) {
                        
                        // @todo: Merge Plugin Defaults in-case there are none in the plugin check.
                        if ($data['required'] && !$this->_plugin_version_check($data['version'], $this->item_array[$plugin]['settings']['version'], $data['oper'])) {
                                if ($this->check($plugin))      // is it even installed?
                                        return false;
                        }
                }
                
                //      if everything passes.. tell it ok!
                return true;    
        }
        
        function register() {
                /**
                 * Major Code Upgrade
                 */
                $temp = array(
                        'contact_form_7' => array (
                                'settings' => array (
                                        'type' => 'plugin',
                                        'version' => '1.10.0.1'
                                ),
                                'wordpress' => array (
                                        'version' => '2.5',
                                        'oper' => '>='
                                        ),
                                'plugins' => array (
                                        'really_simple_captcha' => array (
                                                'required' => false,
                                                'version' => '1.0',
                                                'oper' => '>='
                                        ),
                                        'really' => array (
                                                'required' => true,
                                                'recommended' => '0.5',
                                                'version' => '0.1',
                                                'oper' => '>='
                                        ),
                                )
                        ),
                        'really' => array (
                                'settings' => array (
                                        'type' => 'plugin',
                                        'version' => '0.3'
                                ),
                                'wordpress' => array (
                                        'version' => '2.8',
                                        'oper' => '>='
                                )
                        ),
                );
                
                foreach ($temp as $item_name => $data) {
                        $this->item_array[$item_name] = $data;
                        // tell the plugin that their checks are register'ed correctly
                        do_action('dependency_registered_' . $item_name);
                        do_action('dependency_registered', $item_name); //      catch all action tigger.
                }
                
        }
        
        // Private Functions
        /** 
         * 
         * Get the plugin requirments.
         *
         * @param string $item_id The plugin sanitized name.
         * 
         */
        function _get_item_data($item_id) {
                if (is_array($this->item_array[$item_id]))
                        return $this->item_array[$item_id];
                
                return false;
        }
        
        /** 
         * 
         * Checks to see if the item we are checking has the 
         * minuium requirments for this WordPress installation.
         *
         * @param string $version The version of WordPress needed for this theme/plugin to work.
         * @param string $oper How we should compare the version numberes.
         * @return boolen True if it's allowed, false if it doesn't pass muster.
         * 
         */
        function _wordpress_version_check($version, $oper) {
                global $wp_version;
                
                if (version_compare($wp_version, $version, $oper))
                        return true;
                else
                        return false;
        }

        /** 
         * 
         * Checks to see if the item we are checking has the 
         * minuium requirments for this WordPress installation.
         *
         * @param string $version The version of plugins needed for this theme/plugin to work.
         * @param string $plugin_version The version of Plugins needed for this theme/plugin to work.
         * @return boolen True if it's allowed, false if it doesn't pass muster.
         * 
         */
        function _plugin_version_check($version, $plugin_version, $oper) {
                if (version_compare($plugin_version, $version, $oper))
                        return true;
                else
                        return false;           
        }

}
        
?>