root/trunk/common/plugins.php

<?php
/**
 * MvBlog -- An open source no-nosense blogtool
 *
 * Copyright (C) 2005-2008, Michiel van Baak
 * Michiel van Baak <mvanbaak@users.sourceforge.net>
 *
 * See http://dev.mvblog.org for more information on MvBlog.
 * That page also provides Bugtrackers, Filereleases etc.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 *
 * @package MvBlog
 * @author Michiel van Baak
 * @version 2.0
 * @copyright 2005-2008 Michiel van Baak
 */
/**
 * Class that holds methods to manage plugins etc.
 * @package MvBlog
 */
Class MvBlog_pluginmgr {

    /* constants */

    /* variables */
    /**
     * @var array $plugins Contains all loaded plugin objects
     */
    public $plugins = array();
    /**
     * @var string $plugindir The directory that holds all the plugins
     */
    public $plugindir = "";

    /* methods */
    /* __construct {{{ */
    /**
     * Load all plugins into plugins array
     *
     * @param string $plugindir The dir to load
     */
    public function __construct($plugindir, &$mvblog) {
        /* make sure the dir is set and that it contains sane data */
        if (!strlen($plugindir)) die("Plugindir not given");
        $plugindir = str_replace("../../", "", $plugindir); // get rid of ../
        $plugindir = preg_replace("/^\//si", "", $plugindir);   // get rid of .
        /* check if it is there, if not look 1 level up, not more */
        if (!is_dir($plugindir)) {
            $plugindir = "../".$plugindir;
        }
        $this->plugindir = $plugindir;

        /* read all files and init the objects */
        $handle = opendir($this->plugindir);
        while (false !== ($file = readdir($handle))) {
            if (strpos($file, ".") === 0) continue; // dont process . .. or hidden files/dirs
            if (is_dir($this->plugindir.$file)) continue; // dont process directories
            /* get the filename */
            /* all files should be: pluginname.php */
            $plugin = explode(".", $file);
            $filename = $plugin[0];
            require_once($this->plugindir.$file);
            $this->plugins[$filename] = new $filename($mvblog);
            // FB: 20070304: Eval isn't needed here. Commented out and replaced
            // by the line above. This fixed 'undefined constant' errors.
            //eval("\$this->plugins[".$filename."] = new ".$filename."(\$mvblog);");
        }
        /* sort plugins */
        ksort($this->plugins);

    }
    /* }}} */
    /* activate_plugin {{{ */
    /**
     * Activate givin plugin
     * If the plugin is not loaded, do nothing
     *
     * @param string $plugin The plugin name to activate
     * @return bool true on success, false on failure
     */
    public function activate_plugin($plugin) {
        if (array_key_exists($plugin, $this->plugins)) {
            $this->plugins[$plugin]->active = true;
            $this->plugins[$plugin]->activate();
            return true;
        } else {
            return false;
        }
    }
    /* }}} */
    /* deactivate_plugin {{{ */
    /**
     * deActivate givin plugin
     * If the plugin is not loaded, do nothing
     *
     * @param string $plugin The plugin name to deactivate
     * @return bool true on success, false on failure
     */
    public function deactivate_plugin($plugin) {
        if (array_key_exists($plugin, $this->plugins)) {
            $this->plugins[$plugin]->active = false;
            $this->plugins[$plugin]->deactivate();
            return true;
        } else {
            return false;
        }
    }
    /* }}} */
    /* set_active_plugins {{{ */
    /**
     * Activate plugins using an external array.
     * This can be usefull if you store your activate plugins in a database
     *
     * @param array $active_plugins Array with plugin names to activate
     */
    public function set_active_plugins($active_plugins) {
        foreach ($active_plugins as $activate) {
            $this->activate_plugin($activate);
        }
    }
    /* }}} */
    /* get_active_plugins {{{ */
    /**
     * Return array of active plugins
     */
    public function get_active_plugins() {
        $return = array();
        foreach ($this->plugins as $name=>$plugin) {
            if ($plugin->active)
                $return[] = $name;
        }
        return $return;
    }
    /* }}} */
    /* run_hooks {{{ */
    /**
     * Loop through all the plugins and run functions registered to given hooktype
     */
    public function run_hooks($type, $data) {
        foreach ($this->plugins as $plugin) {
            /* only run when the plugin is active */
            if ($plugin->active) {
                foreach ($plugin->hooks as $hook=>$function) {
                    if ($hook == $type) {
                        $data = eval("return \$plugin->$function(\$data);");
                    }
                }
            }
        }
        return $data;
    }
    /* }}} */
}

/**
 * Default Plugin class with predefined variables and addHook function.
 * All plugins should extend on this one
 */
Class MvBlog_plugin {
    public $hooks  = array(); // de array van alle hooks en functies daaraan gebonden
    public $active = false; // standaard is de plugin uitgeschakeld

    public function addHook($hook_name, $function_name){
        $this->hooks[$hook_name] = $function_name;
        $this->description = htmlspecialchars($this->description);
    }
}

/**
 * Plugin interface.
 * A plugin should implement this to assure at least the basics are correct
 */
interface MvBlog_pluginiface {
    public function addHook($hook_name, $function_name);
    public function activate();
    public function deactivate();
}
?>