ability.php

<?php namespace Authority;
/**
* Authority
*
* Authority is an authorization library for CodeIgniter 2+ and PHPActiveRecord
* This library is inspired by, and largely based off, Ryan Bates' CanCan gem
* for Ruby on Rails. It is not a 1:1 port, but the essentials are available.
* Please check out his work at http://github.com/ryanb/cancan/
*
* @package Authority
* @version 0.0.3
* @author Matthew Machuga
* @license MIT License
* @copyright 2011 Matthew Machuga
* @link http://github.com/machuga
*
**/

use Laravel\Config;
use Laravel\Auth;

abstract class Ability {

	protected static $_rules = array();

	protected static $_action_aliases = array();

	public static function can($action, $resource, $resource_val = null)
	{
		// See if the action has been aliased to somethign else
		$true_action = static::determine_action($action);

		$matches = static::find_matches($true_action, $resource);
		
		if(count($matches) === 0)
		{
			return false;
		}

		$rule = end($matches);

		return $rule->allowed($resource_val);
	}

	public static function cannot($action, $resource, $resource_val = null)
	{
		return ! static::can($action, $resource, $resource_val);
	}

	public static function allow($action, $resource, \Closure $callback = null)
	{
		static::$_rules[] = new Rule(true, $action, $resource, $callback);
	}

	public static function deny($action, $resource, \Closure $callback = null)
	{
		static::$_rules[] = new Rule(false, $action, $resource, $callback);
	}

	public static function action_alias($action, Array $aliases)
	{
		static::$_action_aliases[$action] = $aliases;
	}

	public static function dealias($action)
	{
		return static::$_action_aliases[$action] ?: $action;
	}

	protected static function determine_action($action)
	{
		$actions = array();
		if ( ! empty(static::$_action_aliases))
		{
			foreach (static::$_action_aliases as $aliased_action => $aliases)
			{
				if ( ! empty($aliases) && in_array($action, $aliases))
				{
					$actions[] = $aliased_action;
				}
			}
		}

		if (empty($actions))
		{
			return $action;
		}
		else
		{
			$actions[] = $action;
			return $actions;
		}
	}

	protected static function find_matches($action, $resource)
	{
		$matches = array();
		if ( ! empty(static::$_rules))
		{
			foreach(static::$_rules as $rule)
			{
				if ($rule->relevant($action, $resource))
				{
					$matches[] = $rule;
				}
			}
		}
		return $matches;
	}

	public static function reset()
	{
		static::$_rules = array();
		static::$_action_aliases = array();
	}

}