Basic front controller for single page applications

gistfile1.js

/*jshint forin:true, noarg:true, noempty:true, eqeqeq:true, bitwise:true, strict:true, undef:true, curly:true, browser:true, indent:2, maxerr:50 */

/*!
front.js
(c) 2011 Anders Ytterström
front.js may be freely distributed under the MIT license.
TODO: pushState support
*/

/*
USAGE: A route is defined by a path (could be a simple string or a regexp) and a callback (a function).

// static routes
front("books", displayBooks);
front("talks", displayTalks);
front("comments", displayComments);

// dynamic routes
front(/book:[\d+]$/, displayBookDetail);
front(/talk:[\d+]$/, displayTalkDetail);
front(/comment:[\d]$/, displayCommentDetail);

The frontcontroller should be executed when all dependencies are in place and the routes are configured.

front.run(); // defaults to location.hash -> http://example.com
front.run("book:12"); // goto book 12 -> http://example.com#!book:12

location.hash is altered everytime front.run is executed.
*/

(function (global) {
  "use strict";
  var i, _regexps = [], _statics = [];
  
  function addRoute(path, callback) {
    if (typeof path !== "string") { // regexp
      _regexps.push([ path, callback ]);
    } else {
      _statics.push([ path, callback ]);
    }
    return true;
  }
  
  function dispatch(path) {
    // set path
    if (typeof path === "undefined") {
      path = location.hash || "";
      path = path.replace(/^#/, '').replace(/^!/, '');
    }
    
    // cleanup
    var action, args;
    
    // static routes lookup
    i = _statics.length;
    while (i--) {
      if (_statics[i][0] === path) {
        action = _statics[i][1];
        break;
      }
    }
    
    // regexp routes lookup unless a static action was defined.
    if (typeof action !== "function") {
      i = _regexps.length;
      while (i--) {
        args = args = path.match(_regexps[i][0]);
        if (args) {
          action = _regexps[i][1];
          break;
        }
      }
    }
    
    // execute action and update hash unless the action is still undefined
    if (typeof action === "function") {
      if (args instanceof Array) {
        args.shift();
        if (args.length === 1) { args = args[0]; }
      }
      
      action(args);
      
      path = (path.length ? '#!': '') + path;
      
      if (location.hash !== path) {
        location.hash = path;
      }
    }
    
    return false; // for click events.
  }
  
  global.front = addRoute;
  global.front.run = dispatch;
})(this);