Disclaimer: This fork has been updated to work with Backbone 0.9.10

Include backbone_filters.js after Backbone.

In your router where routes are defined as:

routes : {
    "clerks/:arg1/:arg2" : "clerks"
}

clerks : function(arg1, arg2) {
    // router logic, with arg1 and arg2
},

You can now add:

before : {
  '^clerks' : function(route, arg1, arg2) {
    /* do stuff to all routes starting with 'clerks' */
    /* return false to halt execution */
  },
  'another reg ex' : function(route) { }
},

after : {
  '^clerks' : function(route, arg1, arg2) {
    /* do stuff */
  },
  'another reg ex' : function(route) { }
}

Your filters will be called and if a filter returns false, the filter chain is halted. If a before filter chain is halted, the action in the Router will not be called.

Your filters will receive the same arguments that get passed to the actions (following the first argument, route). The route argument contains the entire matched filter segment (including args).