In this step we'll make that happen and learn a bit about routes in Rails.
Step 1: Add a root route
Open the file config/routes.rb in an editor.
Search the file for the line resources :topics. It will be near the top.
Right above that line, add a new line: root 'topics#index'. When you are done the file should look like this:
resources :topics# For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.htmlend
Step 2: Remove the comment (optional)
Near the bottom, there is a line that starts with a #. This is called a
comment. It is ignored by ruby and is used for reference or further
explanation of nearby code. If you want, you can remove it, or keep it
there to look at later. It's totally up to you!
For Cloud9: delete any text after 'amazonaws.com', or click to preview running
application in the editor again
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
root GET / topics#index
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
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 parentheses is optional.
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).