Array Attribute for Ruby Model

Question

Is it possible to create an attribute for a class that is an array? I tried reading this but I didn\'t get much out of it. I want to do something like this:

clas         


        

Answer 1

Rails 6+

In Rails 6 (and to a lesser degree Rails 5) you can use the Attribute API which will allow you to create a typed, "virtual"/non-db backed column and even a default attribute. For example:

attribute :categories, :jsonb, array: true, default: [{ foo: 'bar' }, { fizz: 'buzz' }]

Which results in:

Example.new


# {
            "id" => nil,
    "created_at" => nil,
    "updated_at" => nil,
    "categories" => [
                      [0] {
                        "foo" => "bar"
                      },
                      [1] {
                        "fizz" => "buzz"
                      }
                    ]
}

Note that you can use any type, but if it's not already available, you'll have to register it. In the above case, I use PostgeSQL as the database and which has already registered :jsonb as a type.