I've this code in my Report model:
has_many :report_reasons, :validate => true
has_many :reasons, :through => :report_reasons #, :uniq => true
# :accessible => true
reason_attributes.uniq.each do |reason|
reasons << Reason.find_or_create_by_content(reason)
What I'm trying to accomplish (and what works) is to have a form which
can submit to a Report some Reason via fields_for (Reason :content
So I just swipe existing associations with .clear and proceed to
rebuild new ones.
I like to keep things that way so I have my validation errors back,
this is true especially when saving a new Report.
What happens here is that, according to rails' code, when the owner
object, in this case Report, doesn't exists yet, I can assign to it
every kind of Reason I can think of, most importantly even those that
doesn't pass validation.
Because validations happens at .save I've my errors and I'm quite
However this is different when using update_attributes, for updating.
The owner object (Report) already exists, and every invalid Reason
assigned through << will simply result in a raised
ActiveRecord::InvalidRecord exception. This is best described directly
into rails' code in association_collection.rb (<<) and
Now I may trap this exception in controller and do something with it,
however I lose in some way my validation error messages on my form,
which is dynamic (add/remove reasons via js).
The reason why I'm not using :accessible or some other plugin to ease
multimodel forms is that they wants to create a record in Reason,
which is good, but they don't try to reuse it if it already exists.
Instead they, of course, will duplicate rows, defeating my purpose.
I can post some other code if anybody have some suggestions on how to