Models, Validation and Resources
We are going to create a Cat model to held information about a single cat. Use the model generator to create a simple model:
rails g model cat name:string description:text
You will see we have made a nice cat class in the models directory, and also a migration in the db/migrations directory.
Run the migration using:
This has updated your database schema.
Test using the console
Drop into the rails console by typing:
Exercise - playing with cats
Now you can play with your Cat.
Try out the following commands in the console:
c = Cat.create name: "Markey" Cat.all c.name = "Dave" c.save Cat.first Cat.first.name Cat.find(1)
What do they all do? You can do all this in your controller.
Exercise - A basket full of tiny little cats
Now create 10 more cats, and try out the following.
Cat.order(:name) Cat.order(:name).limit(5) Cat.where(name: "Dave") Cat.where("created_at > ?", Time.now - 1.minute) Cat.count
Exercise - Making use of our cat
Now create a controller and route. The route should point to a method called show in the controller. It should be possible to visit:
In the controller retrieve the cat based on the id in the params hash.
Now make a view to display your cat. Output all the fields nicely.
Optional Extension, create an index page
Create a route of the form:
This should point to the index method in the cat_controller. This method should retrieve all of the cats with Cat.all.
Make a view which loops over the cats, displaying them all. To loop over a collection, you can do something like this:
<% @cats.each do |cat| %> <%= cat.name %> <% end %>