MY_Router.php

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/*
Copyright 2010 Cameron Turner. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are
permitted provided that the following conditions are met:

   1. Redistributions of source code must retain the above copyright notice, this list of
      conditions and the following disclaimer.

   2. Redistributions in binary form must reproduce the above copyright notice, this list
      of conditions and the following disclaimer in the documentation and/or other materials
      provided with the distribution.

THIS SOFTWARE IS PROVIDED BY Cameron Turner ``AS IS'' AND ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those of the
authors and should not be interpreted as representing official policies, either expressed
or implied, of Cameron Turner.
*/

class MY_Router extends CI_Router {
	var $hostregex = '';
	var $hostdir = '';
	
	function _set_routing()
	{
		// Are query strings enabled in the config file?
		// If so, we're done since segment based URIs are not used with query strings.
		if ($this->config->item('enable_query_strings') === TRUE AND isset($_GET[$this->config->item('controller_trigger')]))
		{
			$this->set_class(trim($this->uri->_filter_uri($_GET[$this->config->item('controller_trigger')])));

			if (isset($_GET[$this->config->item('function_trigger')]))
			{
				$this->set_method(trim($this->uri->_filter_uri($_GET[$this->config->item('function_trigger')])));
			}
			
			return;
		}
		
		// Load the routes.php file.
		@include(APPPATH.'config/routes'.EXT);
		$this->routes = ( ! isset($route) OR ! is_array($route)) ? array() : $route;
		unset($route);
		
		// Set the default controller so we can display it in the event
		// the URI doesn't correlated to a valid controller.
		$this->default_controller = ( ! isset($this->routes['default_controller']) OR $this->routes['default_controller'] == '') ? FALSE : strtolower($this->routes['default_controller']);
		unset($this->routes['default_controller']);
		
		// Fetch the complete URI string
		$this->uri->_fetch_uri_string();
		
		// Do we need to remove the URL suffix?
		$this->uri->_remove_url_suffix();
		
		// Compile the segments into an array
		$this->uri->_explode_segments();
		
		// Parse any custom routing that may exist
		$this->_parse_routes();		
		
		// Re-index the segment array so that it starts with 1 rather than 0
		$this->uri->_reindex_segments();
	}
	
	function _validate_request($segments)
	{
		// Does the requested controller exist in the root folder?
		if (file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].EXT))
		{
			return $segments;
		}
		
		// Is the controller in a sub-folder?
		while (count($segments) > 0 && !is_file(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].EXT) && is_dir(APPPATH.'controllers/'.$this->fetch_directory().$segments[0]))
		{
			$this->set_directory($this->fetch_directory().array_shift($segments));
		}
		if (count($segments) > 0)
		{
			if (!file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].EXT))
			{
				show_404($this->fetch_directory().$segments);
			}
		}
		else
		{
			if (!file_exists(APPPATH.'controllers/'.$this->fetch_directory().$this->default_controller.EXT))
			{
				show_404($this->fetch_directory().$this->default_controller);
			}
			return array($this->default_controller);
		}
		
		return $segments;
	}
	
	function _parse_hosts()
	{
		$this->hostdir = $this->uri->host();
		
		// Is there a literal match for host?
		if(isset($this->routes[preg_quote($this->uri->host())]))
		{
			$this->hostregex = preg_quote($this->uri->host());
			return $this->routes[preg_quote($this->uri->host())];
		}
		
		// Loop through the host array looking for wild-cards
		foreach ($this->routes as $key => $val)
		{						
			// Convert wild-cards to RegEx
			$key = str_replace(':any', '.+', str_replace(':num', '[0-9]+', $key));
			
			// Does the RegEx match?
			$matches = array();
			if (preg_match('#^'.$key.'$#', $this->uri->host(), $matches))
			{
				$this->hostregex = $key;
				if(isset($matches['hostdir'])) $this->hostdir = $matches['hostdir'];
				return $val;
			}
		}
		
		return isset($this->routes['default_host']) ? $this->routes['default_host'] : array();
	}
	
	function _parse_routes()
	{
		// Do we even have any custom routing to deal with?
		if (count($this->routes) == 0)
		{
			$this->_set_request($this->uri->segments);
			return;
		}
		
		// Turn the segment array into a URI string
		$uri = implode('/', $this->uri->segments);
		
		// Parse hosts
		$route = $this->_parse_hosts();
		
		$this->config->set_item('host_dir', $this->hostdir);
		
		// Update the default controller and scaffolding command
		if (isset($route['default_controller']))
		{
			$this->default_controller = $route['default_controller'];
			unset($route['default_controller']);
		}
		if (!isset($route['scaffolding_trigger']))
		{
			$route['scaffolding_trigger'] = $this->routes['scaffolding_trigger'];
		}
		
		// If we're on the frontpage, we can skip everything else
		if ($uri == '')
		{
			if ($this->hostdir !== '' && file_exists(APPPATH.'controllers/'.$this->hostdir.'/'.$this->default_controller.EXT))
			{
				$this->_set_request(array_merge(array($this->hostdir), explode('/', $this->default_controller)));
			}
			else
			{
				$this->_set_request(explode('/', $this->default_controller));
			}
			return;
		}
		
		// If there's no routes, there's no need to bother going through the list
		if (count($route) > 1)
		{
			// Is there a literal match for the route? If so we're done
			if (isset($route[preg_quote($uri)]))
			{
				$this->_set_request(explode('/', $this->routes[$uri]));		
				return;
			}
			
			// Loop through the route array looking for wild-cards
			foreach ($route as $key => $val)
			{
				// Convert wild-cards to RegEx
				$key = str_replace(':any', '.+', str_replace(':num', '[0-9]+', $key));
				
				// Does the RegEx match?
				if (preg_match('#^'.$key.'$#', $uri))
				{
					// Do we have a back-reference?
					if (strpos($val, '$') !== FALSE AND (strpos($key, '(') !== FALSE OR strpos($hostregex, '(') !== FALSE))
					{
						$val = preg_replace('#^'.$this->hostregex.'/'.$key.'$#', $val, $uri);
					}
					
					$this->_set_request(explode('/', $val));		
					return;
				}
			}
		}
		
		// Try to see whether the controller exists in a directory with the same name as the host
		if ($this->hostdir !== '' && is_dir(APPPATH.'controllers/'.$this->hostdir))
		{
			$this->set_directory($this->hostdir);
			$segments = $this->uri->segments;
			while (count($segments) > 0 && !is_file(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].EXT) && is_dir(APPPATH.'controllers/'.$this->fetch_directory().$segments[0]))
			{
				$this->set_directory($this->fetch_directory().array_shift($segments));
			}
			if(count($segments) > 0)
			{
				if (file_exists(APPPATH.'controllers/'.$this->fetch_directory().$segments[0].EXT))
				{
					$this->_set_request($segments);
					return;
				}
			}
			else
			{
				if (file_exists(APPPATH.'controllers/'.$this->fetch_directory().$this->default_controller.EXT))
				{
					$this->_set_request(array_merge($segments, array($this->default_controller)));
					return;
				}
			}
			$this->directory = '';
		}
		
		// If we got this far it means we didn't encounter a
		// matching route so we'll set the site default route
		$this->_set_request($this->uri->segments);
	}
}