AngularJS vs. Turbolinks
Turbolinks as well as AnguluarJS can both be used to make a web application respond faster, in the sense that in response to a user interaction something happens on the web page without reloading and rerendering the whole page.
They differ in the following regard:
-
AngularJS helps you to build a rich client-side application, where you write a lot of JavaScript code that runs on the client machine. This code makes the site interactive to the user. It communicates with the server-side backend, i.e. with the Rails app, using a JSON API.
-
Turbolinks, on the other hand, helps to to make the site interactive without requiring you to code JavaScript. It allows you to stick to the Ruby/Rails code run on the server-side and still, “magically”, use AJAX to replace, and therefore rerender, only the parts of the page that have changed.
Where Turbolinks is strong in allowing you use this powerful AJAX mechanism without doing anything by hand and just code Ruby/Rails, there might come a stage, as your application grows, where you would like to integrate a JavaScript framework such as AngularJS.
Especially in this intermedium stage, where you would like to successively integrate AngularJS into your application, one component at a time, it can make perfectly sense to run Angular JS and Turbolinks together.
How to use AngularJS and Turbolinks together
Use callback to manually bootstrap Angular
In your Angular code, you have a line defining your application module, something like this:
# app/assets/javascripts/angular-app.js.coffee
# without turbolinks
@app = angular.module 'MyApplication', ['ngResource']
This code is run when the page is loaded. But since Turbolinks just replaces a part of the page and prevents an entire page load, you have to make sure, the angular application is properly initialized (“bootstrapped”), even after such partial reloads done by Turbolinks. Thus, replace the above module declaration by the following code:
# app/assets/javascripts/angular-app.js.coffee
# with turbolinks
@app = angular.module 'MyApplication', ['ngResource']
$(document).on 'turbolinks:load', ->
angular.bootstrap document.body, ['MyApplication']
Don’t bootstrap automatically
You often see in tutorials how to bootstrap an Angular app automatically by using the ng-app
attribute in your HTML code.
<!-- app/views/layouts/my_layout.html.erb -->
<!-- without turbolinks -->
<html ng-app="YourApplication">
...
But using this mechanism together with the manual bootstrap shown above would cause the application to bootstrap twice and, therefore, would brake the application.
Thus, just remove this ng-app
attribute:
<!-- app/views/layouts/my_layout.html.erb -->
<!-- with turbolinks -->
<html>
...
Further Reading
- AngularJS bootstrapping: http://docs.angularjs.org/guide/bootstrap
- Railscasts on Turbolinks (explains callbacks): http://railscasts.com/episodes/390-turbolinks
- Demo application: https://github.com/fiedl/rails-5-angular-and-turbolinks-demo