Override a default attribute don't behave like expected in form_for

Hello, I have a strange behavior and don’t know why.

If I override attributes from AcitveRecord object like below:

def end_date=(date)
date = date.to_date unless date.blank?
write_attribute(:end_date,date)
end

def end_date
date = read_attribute(:end_date)
I18n.localize(date) if date.present?
end

Everything will work fine but when I try call text_field in a form_for
block I get the database value and ignore end_date getter.

<%= f.text_field :end_date, :class=>“date”, :size=>“10” %>

The text_field will be filled with 2008-12-10 (mysql date) instead of
10/12/2008 ( I18n localized)

Anyone know why we get this behavior?

Looking inside rails code I found text_field use InstanceTag and this
call []before_type_cast and will return my value before turned in ruby
object.
What is the benefit os this behavior?

I can solve my problem forcing value on text_field but I think it is
ugly.

I fix my problem with alias between attribute and
attribute_before_type_cast … I think active record do this because
other kind of columns like decimals or numbers ( i’m not sure ) but
it’s not beautyfull when we need make alias only for make text_field
behave like expected.