Implementing Client-Side Routing


You wish to use client-side routing in conjunction with a Ruby on Rails backend.


Every request to the backend should initially render the complete page in order to load our Angular app. Only then will the client-side rendering take over. Let us first have a look at the route definition for this “catch all” route.

Contacts::Application.routes.draw do
  root :to => "layouts#index"
  match "*path" => "layouts#index"

It uses Route Globbing to match all URLs and defines a root URL. Both will be handled by a layout controller with the sole purpose of rendering the initial layout.

class LayoutsController < ApplicationController
  def index
    render "layouts/application"

The actual layout template defines our ng-view directive and resides in app/views/layouts/application.html - nothing new here. So let’s skip ahead to the Angular route definition in app.js.erb.

var app = angular.module("Contacts", ["ngResource"]);

app.config(function($routeProvider, $locationProvider) {
      { templateUrl: "<%= asset_path('contacts/index.html') %> ",
        controller: "ContactsIndexCtrl" })
      { templateUrl: "<%= asset_path('contacts/edit.html') %> ",
        controller: "ContactsEditCtrl" })
      { templateUrl: "<%= asset_path('contacts/show.html') %> ",
        controller: "ContactsShowCtrl" })
      { templateUrl: "<%= asset_path('contacts/edit.html') %> ",
        controller: "ContactsEditCtrl" })
    .otherwise({ redirectTo: "/contacts" });

We set the $locationProvider to use the HTML5 mode and define our client-side routes for listing, showing, editing and creating new contacts.

You can find the complete example on github.


Let us have a look into the route definition again. First of all the filename ends with erb, since it uses ERB tags in the javascript file, courtesy of the Rails Asset Pipeline. The asset_path method is used to retrieve the URL to the HTML partials since it will change depending on the environment. On production the filename contains an MD5 checksum and the actual ERB output will change from /assets/contacts/index.html to /assets/contacts/index-7ce113b9081a20d93a4a86e1aacce05f.html. If your Rails app is configured to use an asset host, the path will in fact be absolute.