/backbone.routefilter

Before and after filters for Backbone.Router.

Primary LanguageJavaScriptMIT LicenseMIT

Backbone Routefilter

Before and after filters for Backbone.Router. Useful for doing things like client side content not found pages– any time you want to do something to every route before or after it's routed, this is a good way to do it.

Get the source

Download the production version or the development version.

Install using Bower

If you're using Bower to manage your dependencies, simply run bower install --save routefilter.

Overview

Backbone.routefilter works by overriding Backbone.Router.prototype.route. Whenever a router's route method is called, Backbone.routefilter wraps the route callback (or route handler) that's passed in a 'wrapper handler', that calls whatever before or after "filters" you have written along with the original route callback.

Because Backbone.Router.prototype.route is used internally to bind routes to Backbone.history, in addition to being available publicly for ad hoc route handling, Backbone.routefilter will work for you any way you choose to consume Backbone.Router.

Route handling and filtering from a router constructor

You can specify filters in one of two ways:

A single function for before/after

var Router = Backbone.Router.extend({
  routes: {
    "": "index",
    "page/:id": "page"
  },
  before: function( route, params ) { ... },
  after: function( route, params ) { ... },
  index: function(){ ... },
  page: function( route ){ ... }
});

An object with routes and their callbacks

var Router = Backbone.Router.extend({
  routes: {
    "": "index",
    "page/:id": "page"
  },
  before: {
    "": function( route ) { ... },
    "page/:id": function( route ) { ... }
  },
  after: function( route ) { ... },
  index: function(){ ... },
  page: function( route ){ ... }
});

Ad hoc route handling and filtering

var router = new Router();

router.before = function( route, params ) { ... }

router.route("page/:id", "page", function( route ) { ... });

Route Parameters

The second argument to any filter function is an array of the parameter values. So if your route looks like: page/:id/users/:userid, and you trigger route: page/12/users/100, then your params variable will be set to: [12, 100].

Note if you are specifying your filters per route rather than a single callback, do not overwrite it by calling router.before = function... since it will overwrite the entire object you've defined including all other routes! In that case, just define the specific route that you want to add a filter to like so:

router.before["page/:id"] = function( route ) { ... }

Returning false from within a before filter

If you return false from within a before filter, neither the route's handler, nor the after filter will be run will run. This is useful if you want to catch, say, a bad route, and prevent the router from actually trying to route it. For example:

router.before = function( route, params ) {
  if( !myAcceptableRoutes.indexOf( route ) ){
    return false;
  }
}

What happens if my route doesn't have a handler?

Backbone supports binding routes to route names without actually supplying a route handler callback. Doing so causes Backbone to just dispatch a route:[name] event on the router where the name was matched. If you've written before or after filters, they will be called when any route is matched, whether or not it has a handler callback.

Quick Start

This quickstart is also available in the JSFiddle interactive editor: http://jsfiddle.net/boaz/AjFCV/4/.

<!doctype>
<html>
<head>
<script src="http://code.jquery.com/jquery.js"></script>
<script src="http://underscorejs.org/underscore.js"></script>
<script src="http://backbonejs.org/backbone.js"></script>
<script src="https://raw.github.com/boazsender/backbone.routefilter/master/dist/backbone.routefilter.js"></script>
<script>
jQuery(function($) {
  // Set up a a Router.
  var Router = Backbone.Router.extend({
    routes: {
      "": "index",
      "page/:id": "page"
    },
    before: function( route ) {

      // Do something with every route before it's routed. "route" is a string
      // containing the route fragment just like regular Backbone route
      // handlers. If the url has more fragments, the before callback will
      // also get them, eg: before: function( frag1, frag2, frag3 )
      // (just like regular Backbone route handlers).
      if( route === 'foo') {
        console.log('The before filter ran and the route was foo!');
      }

      // Returning false from inside of the before filter will prevent the
      // current route's callback from running, and will prevent the after
      // filter's callback from running.

    },
    after: {

      // define a specific callback for a certain route.
      "page/:id" : function( route ) {
        console.log("After callback for page/:id was run!");
      }
    },
    index: function(){

      // Do what ever you would normally do inside of a route handler.
      console.log('navigated to index.');

    },
    page: function( route ){

      // Do what ever you would normally do inside of a route handler.
      console.log('navigated to page and the route was: ' + route + '.');

    }
  });

  // Instantiate the Router.
  var router = new Router();

  // Start the history.
  Backbone.history.start();

  // Navigate to a page. (Open your console to see what's happening.)
  router.navigate('page/foo', true);

  // Override the before filter on the fly.
  router.before = function( route ) {
    if( route === 'bar' ){
      // return false to stop ecexution of the callback for this route,
      // and the after callback if we navigate to page/bar.
      console.log('We navigated to another page, but the page callback and after filter did not run because we returned false from inside the before filter');
      return false;
    }
  };

  // Navigate to a place that our before filter is written to handle.
  router.navigate('page/bar', true);
});

</script>
</head>
<body>
</body>
</html>

Release History

  • v0.2.1 - 04/05/2014 - becomes AMD compliant and adds bower support. thanks to MrBri (and @powmedia and @gdw2 as well).
  • v0.2.0 - 02/16/2013 - changes route handler param order and adds support for targeting specific routes in each filters thanks to Irene Ros.
  • v0.1.1 - 02/16/2013 - adds support for getting access to matched routes thanks to @wanderer.
  • v0.1.0 - 08/29/2012 - backbone.routefilter first release (unit test coverage, stable api, and stable plugin approach).
  • v0.1.0-pre - 08/28/2012 - backbone.routefilter is pre release

License

Copyright (c) 2014 Boaz Sender Licensed under the MIT, GPL licenses.

Contributing

In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using grunt. In addition to ensuring that your contributions do not introduces regressions by running the Backbone.routefilter tests, please also take the time to run your contributions against the entire Backbone unit test suite.

Important notes

Please don't edit files in the dist subdirectory as they are generated via grunt. You'll find source code in the src subdirectory!

While grunt can run the included unit tests via PhantomJS, this shouldn't be considered a substitute for the real thing. Please be sure to test the test/*.html unit test file(s) in actual browsers.

Installing grunt

This assumes you have node.js and npm installed already.

  1. Test that grunt is installed globally by running grunt --version at the command-line.
  2. If grunt isn't installed globally, run npm install -g grunt to install the latest version. You may need to run sudo npm install -g grunt.
  3. From the root directory of this project, run npm install to install the project's dependencies.

Installing PhantomJS

In order for the qunit task to work properly, PhantomJS must be installed and in the system PATH (if you can run "phantomjs" at the command line, this task should work).

Unfortunately, PhantomJS cannot be installed automatically via npm or grunt, so you need to install it yourself. There are a number of ways to install PhantomJS.

Note that the phantomjs executable needs to be in the system PATH for grunt to see it.