Rails: How do I create a default value for attributes in Rails activerecord's model? [duplicate]

Answer 1

As I see it, there are two problems that need addressing when needing a default value.

1. You need the value present when a new object is initialized. Using after_initialize is not suitable because, as stated, it will be called during calls to #find which will lead to a performance hit.
2. You need to persist the default value when saved

Here is my solution:

# the reader providers a default if nil
# but this wont work when saved
def status
  read_attribute(:status) || "P"
end

# so, define a before_validation callback
before_validation :set_defaults
protected
def set_defaults
  # if a non-default status has been assigned, it will remain
  # if no value has been assigned, the reader will return the default and assign it
  # this keeps the default logic DRY
  status = status
end

I'd love to know why people think of this approach.