Backbone router before,after,leave

backbone-router-filter.js

(function(Backbone, _) {
  var leave;

  _.extend(Backbone.Router.prototype, Backbone.Events, {
    route : function(route, name, callback) {
      var before
        , fn = callback
        , after;

      Backbone.history || (Backbone.history = new Backbone.History);
      if (!_.isRegExp(route)) route = this._routeToRegExp(route);
      if (!fn) fn = this[name];

      if(typeof callback == 'object'){
        before = callback.before;
        fn = callback.route;
        after = callback.after;
      }

      Backbone.history.route(route, _.bind(function(fragment) {
        var args = this._extractParameters(route, fragment);

        if(leave){
          if(leave.apply(this, args) === false)
            return;
          else
            leave = false;
        }

        if(before && before.apply(this, args) === false) return;
        fn.apply(this, args);
        if(after && after.apply(this, args) === false) return;

        if(typeof callback == 'object')
          leave = callback.leave;

        this.trigger.apply(this, ['route:' + name].concat(args));
        Backbone.history.trigger('route', this, name, args);
      }, this));
      return this;
    }
  });
}).call(this, Backbone, _);

routes-example.js

{
  routes: {
    'index': 'index'
  },

  index: {
    before: function(){},
    route: function(){}, // Main route function
    after: function(){},
    leave: function(){}
  }
}

Hi, thanks for this.

I noticed that callback was undefined, in the original Backbone.prototype.route function there is a line if (!callback) callback = this[name];

See my clone of this gist https://gist.github.com/richardassar/5126900

I've also updated my copy to provide the correct arguments to the leave function (instead I was getting the arguments for the subsequent route).