MY_Route.php

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/* load the MX_Router class */
require APPPATH."third_party/MX/Router.php";

/**
 * Extends HMVC Modular Extension to modify route parsing
 * to use Route class instead of default route handler
 *
 * 
 **/
class MY_Router extends MX_Router {
    
    public function _parse_routes()
    {
        // Turn the segment array into a URI string
        $uri = '/'.implode('/', $this->uri->segments).'/';
        
        $routes = Route::fetch();
        
        foreach ($routes as $prefix => $group)
        {
            // test prefix match, of not, just skip to next group
            if (strpos($uri, $prefix) !== 0)
            {
                continue;
            }
            
            // prefix match, try to check full route
            foreach ($group as $route)
            {
                // Does the RegEx match?
                if (preg_match('#^'.$route['regex'].'$#', $uri, $params))
                {
                    // matched parameter will be replaced to the result
                    // we don't need [0] so we remove it here
                    unset($params[0]);
                    
                    // prepare default value for route
                    $params = array_merge($route['default'], $params);
                    
                    // replace matched value to the result route
                    foreach ($params as $name => $value)
                    {
                        $route['handler'] = str_replace(':'.$name, $value, $route['handler']);
                    }
                    
                    // here we go
                    return $this->_set_request(explode('/', $route['handler']));
                }
            }
        }
    
        // 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);
    }
}

// -------------------------------------------------------------------------

/**
 * Main Route class
 *
 * @todo more document on this class
 * 
 **/
class Route {
    
    /**
     * Rules collection
     **/
    public static $rules = array();
    
    /**
     * Named rules collection
     **/
    public static $named = array();
    
    // -------------------------------------------------------------------------
    
    /**
     * Create a Route Group Object
     *
     * @param String $location route prefix for this group
     * @return Route_Group
     **/
    public static function group($location)
    {
        return new Route_Group($location);
    }
    
    // -------------------------------------------------------------------------
    
    /**
     * Create a Route Group object
     * with admin_base configuration options prepended
     * this is just to make it quick to add a route to admin area
     * You can change url to admin anytime by changing $config['admin_base'] in config.php
     * with named route feature, all your link will be automatically updated
     *
     * @param String $location route to admin
     * @return Route_Group
     */
    public static function admin($location)
    {
        return self::group('/'.config_item('admin_base').$location);
    }
    
    // -------------------------------------------------------------------------
    
    /**
     * Fetch Rule collection
     *
     * @param String name of group, default to all
     * @return Array 
     */
    public static function fetch($name = NULL)
    {
        if (is_null($name))
        {
            return self::$rules;
        }
        
        if (isset(self::$rules[$name]))
        {
            return self::$rules[$name];
        }
        
        return array();
    }
    
    // -------------------------------------------------------------------------
    
    /**
     * Url resolve for a specific route using its name and values
     * You can then use site_url or redirect to make it a correct link
     *
     * @param  String $name   name of route to resolve
     * @param  Array  $params parameter to resolve to route
     * @return String         ready to use route, raise an exception if not found or unable resolve route parameter
     **/
    public static function to($name, $params = array())
    {
        // try to find pattern in named route
        if ( ! isset(self::$named[$name]))
        {
            throw new Exception('RouteLinker cannot found any route matched with given name ('.$name.')');
        }
        
        $pattern = self::$named[$name]['pattern'];
        
        // any parameter binding in pattern
        if (preg_match_all('~:\w+~', $pattern, $matches))
        {
            // override default value with given parameter
            $params = array_merge(self::$named[$name]['default'], $params);
            
            // replace each token with parameter value
            // raise an error if unable to resolve value for params
            foreach ($matches[0] as $args)
            {
                $key = substr($args, 1);
                
                // if no value binding for parameter and no default value defined in route
                // raise an error, cause we cannot let any token left in url
                if ( ! isset($params[$key]) AND ! isset($default[$key]))
                {
                    throw new Exception('RouteLinker cannot found any value for parameter name ('.$key.') in '.self::$named[$name]['pattern']);
                }
                
                $pattern = str_replace($args, $params[$key], $pattern);
            }
        }
        
        // remove heading and trailing slash from pattern
        // so this pattern can process with site_url() or redirect() later
        $pattern = trim($pattern, '/');
        
        return $pattern;
    }
    
    
}

// -------------------------------------------------------------------------

/**
 * Route Group class
 *
 * Most of time, you wouldn't initiate this class directly
 * but from returning object of Route::group() or Route::admin()
 * This class contains 2 important method for your routing
 * which are Route::group('/')->addRules() and Route::group('/')->addRule()
 *
 */
class Route_Group {
    
    protected $base;
    
    /**
     * Constructor, set base route passing by Route::group or Route::admin
     *
     * @param String $base base route or route group prefix
     **/
    public function __construct($base = '')
    {   
        $this->base = $base;
    }
    
    // -------------------------------------------------------------------------
    
    /**
     * Add multiple Rules at once
     *
     * Generally you should use this method for main route registering
     * to make your route clean 
     *
     * @todo write more detail on $rules array structure ...
     *
     * @param Array $rules collection of rule definition
     * 
     **/
    public function addRules($rules)
    {
        foreach ($rules as $name => $rule)
        {
            $this->addRule($name, $rule);
        }
    }
    
    // -------------------------------------------------------------------------
    
    /**
     * Add single rule, one by one
     *
     * @param String $name unique identifier of this route (for internal linking purpose)
     * @param Array  $rule Rule definition 
     **/
    public function addRule($name, $rule)
    {
        // create container if not already existed
        if ( ! isset(Route::$rules[$this->base]))
        {
            Route::$rules[$this->base] = array();
        }
        
        // prepend prefix to route
        $rule[0] = $this->base . $rule[0] . '/';
        
        // turn a pattern into regular expression, for using on parsing route in MY_Route::_parse_routes()
        $regex = preg_replace('~:(\w+)~', '(?P<$1>[^/]+)', $rule[0]);
        
        // restructure the rules to make it more readable
        // and append to Collection
        Route::$rules[$this->base][$name] = array(
            'pattern' => $rule[0],
            'regex'   => $regex,
            'handler' => $rule[1],
            'default' => isset($rule[2]) ? $rule[2] : array()
        );
        
        // create additional named rule index
        // needed in url resolving process
        Route::$named[$name] = array(
            // delete all regex optional flag (whatever)?
            'pattern' => preg_replace('~\((.*?)\)\?~', '$1', $rule[0]),
            'default' => isset($rule[2]) ? $rule[2] : array()
        );
    }
}

/* end ./application/core/MY_Router.php */

news.php

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class News extends MX_Controller {
    
    public function category($category, $page)
    {
        echo 'Looking for category name "'.$category.'", page "'.$page.'"';
        echo 'Linking back using ' . site_url(Route::to('news.category', array('category' => 'sports', 'page' => 15)));
    }
    
}

/* End ./modules/news/controllers/news.php */

routes.php

<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

$route['default_controller'] = "home";
$route['404_override'] = 'error/notfound';
$route['error/404']    = $route['404_override'];

// -------------------------------------------------------------------------
// Example - NEWS Module Route

Route::group('/news')->addRules(array(
    'news.category' => array('/:category(/page/:page)?', 'news/category/:category/:page', array('page' => 1)),
    'news.detail'   => array('/:url',                    'news/detail/:url')
));

Route::admin('/news')->addRules(array(
    'admin.news.list'   => array('/page/:page', 'news/admin/news/page', array('page' => 1)),
    'admin.news.add'    => array('/add',        'news/admin/news/add'),
    'admin.news.edit'   => array('/edit/:id',   'news/admin/news/edit/:id'),
    'admin.news.trash'  => array('/trash/:id',  'news/admin/news/trash/:id'),
    'admin.news.delete' => array('/delete/:id', 'news/admin/news/delete/:id'),
    'admin.news.view'   => array('/view/:id',   'news/admin/news/view/:id'),
    'admin.news.edit'   => array('/edit/:id',   'news/admin/news/edit/:id')
));

Route::admin('/news/category')->addRules(array(
    'admin.news.category.list'   => array('/page/:page', 'news/admin/category/page/:page', array('page' => 1)),
    'admin.news.category.add'    => array('/add',        'news/admin/category/add'),
    'admin.news.category.edit'   => array('/edit/:id',   'news/admin/category/edit/:id'),
    'admin.news.category.trash'  => array('/trash/:id',  'news/admin/category/trash/:id'),
    'admin.news.category.delete' => array('/delete/:id', 'news/admin/category/delete/:id')
));

/* end ./application/config/routes.php */