Question

I am following a tutorial and got to this point: http://rubysource.com/building-your-first-rails-application-views-and-controllers/

rails generate controller urls new

The reason we only passed in the new action (instead of new, create,
and show) is because Rails automatically generates a dummy view for
each action included in the generator call. In this case, we only want
a dummy view for the new action, so we exclude the others.

So why we only need to create the controller for new? Can someone plase explain it in a little more details?

Answer 1

The command is used to create the UrlsController with only one method: new.

This command will also automatically create a view file for you in:

app/views/urls/new.html.erb

Had you supplied more arguments like:

rails generate controller urls new create show

You would have gotten:

app/views/urls/new.html.erb
app/views/urls/create.html.erb
app/views/urls/show.html.erb

Since the tutorial only needs the new view it was unnecessary to create the additional views, hence those additional arguments were not added to the generate command.

Later in the tutorial you manually add the create and show methods, but you never add views for those methods (since those methods will not be needing specific views files in this application).

So: what you did was create the controller UrlsController with one method new, and the corresponding view for that method. The rest of the methods you will code in manually later in the tutorial so there was no need to auto-generate anything else (create or show).