Overriding Default Getters in ActiveRecord

I find somewhat frequent occasions where dynamic Model getters are handy. The most common case is where you want to use the value of one attribute unless it's nil, in which case you want to use another attribute instead. You could do @object.field1 || @object.field2, but that's not very DRY if you do it often.

Instead, you can override the default attribute accessor that ActiveRecord builds for you with code like the following:

    1 def field1
    2   val = read_attribute(:field1)
    3   return val || self.field2
    4 end

The trick is the read_attribute(:symbol) method (it has a sister method: write_attribute(:symbol, value)). That obtains the current ActiveRecord value for the field (which you need to return if it's non empty).