backbone.blazer

A better router for Backbone and Marionette applications

learn more here (presentation) and here (video)

installation

bower install backbone.blazer

<script src='jquery.js'></script>
<script src='underscore.js'></script>
<script src='backbone.js'></script>
<script src='bower/path/to/backbone.blazer.js'></script>
<script src='app.js'></script>

huh? what's this?

In order to build a modularized routing system, we've extended and overriden a few parts of the core Backbone.Router. This library attempts to be a mostly drop-in replacement for the normal Backbone router. However, we have removed a few things.

what's in the box?

Backbone.Blazer.Router still supports the usual way of routing in a Backbone application: mapping a regexp to a callback. However, we've gone ahead and added a new way of configuring your routes: Backbone.Blazer.Route.

Router Configuration

Blazer's router supports all the familiar configuration of Backbone.Router

var MyRouter = Backbone.Blazer.Router.extend({
  routes: {
    'regular-old-route': function(routeData) {
      // do whatever you want
    }
  }
});

In addition to the old way of routing, Blazer provides a new strategy: using a Route object.

var MyRouter = Backbone.Blazer.Router.extend({
  routes: {
    'new-hot-route': new HotRoute()
  }
});
 
var HotRoute = Backbone.Blazer.Route.extend({
  execute: function(routeData) {
    // the code that would normally go in your router callback can now go here
  }
});

Route objects can do more than just view rendering. Route objects can also be configured to perform asynchronous actions before rendering your views (or really before calling your execute method).

For example, here's a route that loads some data from some Backbone Model before rendering a view:

var LoadSomeDataRoute = Backbone.Blazer.Route.extend({
  prepare: function(routeData) {
    routeData.someData = new SomeData();
    return routeData.someData.fetch();
  },
  execute: function(routeData) {
    App.getRegion('main').show(new SomeDataView({ model: routeData.someData }));
  }
});

The Blazer router expects the prepare method to return a promise. If the promise is resolved as a success, then the execute method is called; otherwise, the route's error method is called (if provided).

Filters

Configuration

Both Router and Route objects can define filters that run before and after a route is invoked. Filters are specified as an array of objects, where each object has a beforeRoute and/or afterRoute functions.

var FilteredRoute = Backbone.Blazer.Route.extend({
  filters: [{
    beforeRoute: function() {
      // I run before my prepare() method is called
    },
    
    afterRoute: function() {
      // I run after my execute() method is called
    }
  }]
});
 
var Router = Backbone.Blazer.Router.extend({
  routes: {
    'route1': new FilteredRoute(),
    'route2': new OtherRoute()
  },
 
  filters: [{
    beforeRoute: function() {
      // I run before prepare() is called on all routes
    },
    
    afterRoute: function() {
      // I run after execute() is called on all routes
    }
  }]
});
 

Ordering

Filters will run in the order they are sepcified in the filters array. A filter that needs to do some asynchronous work can return a promise and the next filter in the chain will not be run until that promise is resolved. Because of this, it is safe to mix filters that do synchronous work with filters that do asynchronous work.

Filters on a Router object will be run for all Route objects on that router. When invoking a specific route, the router's filters will all run before filters on the route in question are run.

Halting Execution

If a filter returns a promise and that promise is rejected or simply never resolves, the filter chain will stop executing and subsequent filters in the chain will not be invoked. In the case of before filters the prepare() function will never be invoked.

Redirecting

You can stop redirect to another route at any point during route invokation. Doing this will stop execution of the current route. For instance, if a beforeRoute filter redirects then prepare and execute will not be invoked for the current route. Similarly, if prepare redirects then execute will not be invoked for the current route.

var Route = Backbone.Blazer.Route.extend({
  filters: [{
    beforeRoute: function() {
      if (somethingBadHappened()) {
        return this.redirect('another_route');
      }
    }
  }]
});

API

Backbone.Blazer.Router

events

• before:execute, with payload [routeData]. this is the first thing that happens when processing a route.
• after:execute, with payload [routeData]. this is the last thing called when processing a route. only called if execute was actually called.
• error, with payload [routeData, argsFromRejectedPromise]

The router accepts the same parameters as the normal Backbone.Router.

The entries in the routes hash can contain any of the following:

• a callback function in the form: function(routeData) {}
• a router method in the form: function(routeData) {}
• a Backbone.Blazer.Route object

Backbone.Blazer.Route

events

• before:execute, with payload [routeData]. this is the first thing that happens when processing a route.
• after:execute, with payload [routeData]. this is the last thing called when processing a route. only called if execute was actually called.

#prepare(routeData)

• returns a promise (default value is a successfully resolved promise)

#execute(routeData)

• called if the promise from #prepare resolves to success

#error(routeData, argumentsFromRejectedPromise)

• called if the promise from #prepare resolves to failure
• returning true will prevent the router from bubbling the error back up through itself to the application.

#redirect(fragment)

• return this from within any beforeRoute, afterRoute, prepare, execute or error function and execution for this route will stop immediately and a new route corresponding to the provided fragment will be invoked.

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Legal Schtuff (MIT License)

Any contributions made to this project are covered under the MIT License, found here