Now that the structure is complete, let's make the flow work smoothly.
Currently when you go to <http://localhost:3000> you see the "Welcome aboard" message.
It would be easier to use our app if <http://localhost:3000> went directly to the topics list.
In this step we'll make that happen and learn a bit about routes in Rails.
step "Add a root route" do
message "Open the file `config/routes.rb` in an editor (In the InstallFest yesterday, we suggested that you install and use **Atom** as your editor)."
message "Look for the line `Rails.application.routes.draw` at the beginning of the file, and add the line `root 'topics#index'` after it. When you are done the start of the file should look like this:"
source_code :ruby, <<-RUBY
message "(Rails 3.x users should add `root to: 'topics#index'` and will need to remove their `public/index.html` file)."
step "Confirm your changes" do
message "Go back to <http://localhost:3000/>. You should be taken to the topics list automatically."
tip "Docker users will need to run `docker-compose run web bash` first, where they can then run Rails related commands."
* `root 'topics#index'` is a Rails route that says the default
address for your site is `topics#index`. `topics#index` is the topics
list page (the topics controller with the index action).
* Rails routes control how URLs (web addresses) get matched with
code on the server. Similar to how addresses match with houses and
* The file `config/routes.rb` is like an address directory listing the
possible addresses and which code goes with each one
* `routes.rb` uses some shortcuts so it doesn't always show all the
possible URLs. To explore the URLs in more detail we can use the
At the terminal type `rails routes`. You should get something that
looks like this:
$ rails routes
Prefix Verb URI Pattern Controller#Action
topics GET /topics(.:format) topics#index
POST /topics(.:format) topics#create
new_topic GET /topics/new(.:format) topics#new
edit_topic GET /topics/:id/edit(.:format) topics#edit
topic GET /topics/:id(.:format) topics#show
PATCH /topics/:id(.:format) topics#update
PUT /topics/:id(.:format) topics#update
DELETE /topics/:id(.:format) topics#destroy
root GET / topics#index
This shows all the URLs your application responds to. The code that starts with colons are variables so :id means the id number of the record. The code in parenthesis is optional.
You can also get this information on your site in development. Go to <a href="http://localhost:3000/rails/info">http://localhost:3000/rails/info</a> and you'll see something like this:
<img src='img/rails4_rails_info_routing.png' alt='Screenshot of browser-based Rails routing info page'>
You'll also see that table in whenever you try to access an invalid route (try <a href="http://localhost:3000/sandwich">http://localhost:3000/sandwich</a>)
### Exploring Routes (optional)
Now you can have a look at the paths that are available in your app.
Let's try looking at one of the topics routes we just generated.
Open up your Rails console and play:
$ rails console
`app` is a special object that represents your entire application.
You can ask it about its routes (as we just did), play with its
database connections, or make pseudo-web requests against it with
`get` or `post` (and lots more).