[feature/extension-manager] Extract extension provider functionality from cron

PHPBB3-10323

phpBB/includes/extension/provider.php

@@ -0,0 +1,65 @@
+<?php
+/**
+*
+* @package extension
+* @copyright (c) 2011 phpBB Group
+* @license http://opensource.org/licenses/gpl-license.php GNU Public License
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+/**
+* Provides a set of items found in extensions
+*
+* @package extension
+*/
+abstract class phpbb_extension_provider implements IteratorAggregate
+{
+	/**
+	* Array holding all found items
+	* @var array
+	*/
+	protected $items = array();
+
+	/**
+	* An extension manager to search for items in extensions
+	* @var phpbb_extension_manager
+	*/
+	protected $extension_manager;
+
+	/**
+	* Constructor. Loads all available items.
+	*
+	* @param phpbb_extension_manager $extension_manager phpBB extension manager
+	*/
+	public function __construct(phpbb_extension_manager $extension_manager)
+	{
+		$this->extension_manager = $extension_manager;
+
+		$this->items = $this->find();
+	}
+
+	/**
+	* Finds template paths using the extension manager.
+	*
+	* @return array     List of task names
+	*/
+	abstract function find();
+
+	/**
+	* Retrieve an iterator over all items
+	*
+	* @return ArrayIterator An iterator for the array of template paths
+	*/
+	public function getIterator()
+	{
+		return new ArrayIterator($this->items);
+	}
+}