Interactive plugin system

Jonnee · 08-11-2008, 01:06 PM

Hello all users of TalkPHP

I have been reading and looking and writing user system. Now I had this idea to make this plug&play style plugin system so you only need to upload the plugin to ftp folder and active it from controlpanel.

So what I have now is this :

Code:

<?php

if( !defined( "INPROCESS" ) ){
	header("HTTP/1.0 403 Forbidden");
	die();
}
 include_once 'mysql'. EXT; 
class plugin extends mysql{  
 
 	var $mysql;
 	var $fullpath;
 	var $plugins = array();
 	
	function __construct() {
		
		$this->mysql = new mysql();
		
		if( phpversion( ) < 5 ){
            mysql::__construct( );
        }
        
        // Lets check all avaible plugins
       	$list = array();     

		if ( ($directoryHandle = opendir( $this->fullpath . '/plugins/' )) == true ) {  
			while (($file = readdir( $directoryHandle )) !== false) {  
			// Make sure we're not dealing with a file or a link to the parent directory  
				if( is_dir( $this->fullpath . '/plugins/' . $file ) && ($file == '.' || $file == '..') !== true )  
					array_push( $list, $file );  
			}  
		}  
		
		$results = $this->Fetch_Object('SELECT * FROM plugins');
		
		$newResult = array();
		// Create an array: 'plugin name' = 'active' (1 or 0)  
		foreach ( $results as $result ){  
			$newResult[$result->name] = $result->active;  
		}    
		
		// Register the active plugins 
		foreach( $list as $plugin ){  
			if($newResult[$plugin] == "1"){  
				$this->registerplug($plugin);
			}
		}  
	}
	
	function registerplug($plugin){
		require_once( $this->fullpath . "/plugins/$plugin/$plugin.plugin.php" );
 	}  	
 	
 	function hook($checkpoint){
 		// Cycle through all the plugins that are active  
  		foreach($this->plugins as $plugin){ 
    		if(!call_user_func($checkpoint))  
     			throw new Exception( "Cannot hook plugin ($plugin) at checkpoint ($checkpoint)" );  
   		}  
 	}
  
}
?>

And I use it like this ->

Code:

$plugin = new plugin;
$plugin->fullpath =  $system_folder;
if( phpversion() < '5' ) 
    $plugin->__construct( );

Now when I try to hook functions I use it like this :

Code:

$plugin->hook('Menu'); 
$plugin->hook('onLoad');

So the problem is that it wont print out "hello world" text which I asked it to do in both of those plugins.

Code:

class menu extends plugin {
    function Menu(){
        print 'Hello World!';
        return true;
    }
}

So what is wrong with this? Any suggestions? MySQL connections work 100% for sure (tested)

jlodell · 02-22-2009, 06:38 AM

First, the actual registration of the plugin is missing.
It just includes the plugin class file.
Try this as your registerplug method.

function registerplug($plugin){
// if the plugin isn't already registered
if(!array_key_exists($plugin,$this->plugin)){
// include library file
require_once($this->fullpath.
"/plugins/$plugin/$plugin.plugin.php");
// create instance of plugin
$this->plugin[$plugin] = new $plugin;
}
return $this;
}

And this for the hook method...

function hook($checkpoint){
// Cycle through all the plugins that are active
foreach($this->plugins as $key=>$plugin){
if(!method_exists($plugin,$checkpoint)){
throw new Exception("Cannot hook plugin($key) at checkpoint ($checkpoint)");
}
$this->results[$key] = $plugin->$checkpoint();
}
}

This is just real dirty implementation on what you already have. There are better ways to go about this. some shortcomings include the fact that method exists will show private and protected members which cannot be called like this.
This should make this work and get you moving in the right direction though.

I would pick a common PHP framework and read thru some of the library files that implement similar behavior to get a little inspiration.

cheers,
justin

Jonnee · 02-22-2009, 11:56 AM

Thanks for 'quick' answer

This project has been thrown to recycle bin some time ago already

jlodell · 02-22-2009, 05:26 PM

yeah, i noticed the date after i replied. sorry.