Backbone.js with Rails

7
votes

I'm currently trying Backbone.js along with a rails app. My problem is, that I don't know how to implement the Backbone controllers and views with my rails app. I've read a lot of tutorials, but they are always using just one controller in backbone.js.

For example, I have two controllers in rails.

  • Activities Controller
    • Includes two views, a google map and a search field. The google map is inserted with a backbone view, the searchfield is in HTML and gets its functionality through a backbone view.
    • The search field should fetch data from my rails model and display markers inside the map.

And the other one is

  • Users Controller
    • Here the users profile is viewed, and I want to add some ajax functionality like updating values and other things

In my application.js I start the app using

var App = {
  Views: {},
  Controllers: {},
  Collections: {},
  init: function() {
      new App.Controllers.Activities();
      new App.Controllers.Users();
      Backbone.history.start();
  }
};

$(function() {
  App.init();
});

The problem is, that I don't need the Activities controller in my User Profile and the Users controller in the Rails Activities controller. How could I solve this? Should I try reading the current URL within javascript and then decide which controller is used? Or should I put the JavaScript file into the application.html.erb and then decide here which controller should be used?

Or is this the wrong way to use backbone.js controllers?

Am I getting sth wrong with the structure of backbone.js? Or am I using the Controllers in a wrong way?

Another question is, how to add little JavaScript, in particular jQuery, functionality through Backbone.js? For example, I want to remove the label inside a field, when the user clicks into the field. Or I want to do some tab-functionality and just toggle the visibility of some elements. Should I create for each element that is using javascript a Backbone view? Or is this overload?

Hope I made myself clear and anybody can help, thx!

3
ruby-on-railsbackbone.js

3 Answers

2
votes

Why not make use of the routes feature Backbone provides to decide which method to call? The activities controller would contain only routes use for activities, the user controller only for the user handling, and so forth. Like this you can instantiate the controller just as you do and the routing will decide what happens based on the current location's hash.

If you can't use links with hashes (or there are no such links on your page), I'd simply name my view containers specific enough to attach events only for the current view when needed.

jQuery plugins etc. belong into views IMO. Same goes for your tabs and input hint toggle.

Update

On a general level (and I would not necessarily recommend doing it this way): If you have two methods:

// should be only called for the 'Foo' controller
function foo() {
  alert("FOO");
};

// should be only called for the 'Bar' controller
function bar() {
  alert("BAR");
};

and want to call only one of them depending on the current Rails controller, create a small helper:

e.g. in you *helpers/application_helper.rb*

def body_class
  controller.controller_name
end

then call this method in your layout file (or header partial):

<body class="<%= body_class %>">
…

and use e.g. jQuery to "split" your JS execution:

if ($('body').hasClass('foo')) {
  foo();
} else if ($('body').hasClass('bar')) {
  bar();
}
1
votes

I personally use jammit (from the same author of backbone). You can group stylesheets and javascripts files by module and use them on your different pages. So you create a module for your activities view and another for your user view each requiring the necessary JavaScript file. Two nice things about this:

  • you have only code used on the page loaded on the page
  • jammit comprsses everything for you

This is the way to go when not creating a single page web app where you relies on # routes to navigate from one controller to another. In your case you have multiple single page apps inside a main rails app.

1
votes

Im a Backbone.js newb, so please someone correct me if Im wrong, but I think youre confusing what Backbone controllers are used for.

Backbone.js controllers basically consists of hashbang routes(similar to Rails routes) and actions that these routes call. For instance if you have a rails route that will render a view at http://mysite.com/backbone_test and you have a following backbone route:

var MyController = Backbone.Controller.extend({
  routes: {
    "foo/:bar":            "myFirstFunction"
  },
  myFirstFunction: function(bar){
    console.log(bar);
  });

then if you go to http://mysite.com/backbone_test#foo/THIS-IS-AMAZING then MyController.MyFirstFunction gets executed and "THIS-IS-AMAZING" gets logged in JS console.

Unless you have a direct need for this sort of hashbang-related functionality, such as saving a state of your JavaScript application via an url (for example: http://my.app.com/#key=value&key=value&ad-infinitum=true ) Id advise against using Backbone controllers. You can get all of the functionality u described via Models Collections and Views.

Nice thing about Controllers and Backbone in general is that its modular and different parts can be used independently.

I guess the summary of this answer is that if you dont have a single page javascript application, do not use Backbone Controllers, rely on your rails controllers instead.