Getting Started with Classes and Objects
Most of the Rails files youâll work with and create define classes. (They do so even when they donât have explicit class definitions, as Rails performs some of its magic in the background.) The clearest place to work with objects in Rails is in the controller classes. To get started, therefore, go to the command line and create a new application and a new controller:
rails testbed
...
cd testbed
...
ruby script/generate controller Testbed index
Note
If youâre using Heroku, instead of going to the command line, log in to
Heroku and click on the Create A New Application button from the My
Apps page. You can rename it âtestbedâ if you want, but the
application name doesnât matter much. What does matter is that when
the application editing screen opens, you click on the gear menu near
the bottom left, choose Generate, and enter controller Testbed index
. That will set
things up for the rest of these examples.
For the rest of this appendix, there are only two files that matter: app/views/testbed/index.html.erb and app/controllers/testbed_controller.rb. For right now, replace the contents of app/views/testbed/index.html.erb with:
<%= @result %>
That will make it easy to see the results of the code in the
controller, which is a clearer place to explore Ruby. (@result
is a variable whose value various
examples will set.)
If you open app/controllers/testbed_controller.rb, youâll see the code below. It doesnât yet do anything, except tell the ...
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