ActiveRecord / Nested Attributes create missing association

Rails
1

Hi

I’m working on an issue described in this ticket:
https://rails.lighthouseapp.com/projects/8994/tickets/2415-accepts_nested_attributes_for-doest-work-when-nested_attributes-hash-has-an-id-entry#ticket-2415-6

I’ve a nested form, in which the user can either create a new entry or
choose an existing one. Choosing an existing entry in a nested form is a
problem, because the association in the join table won’t be created (in
Rails 2.3.6 the ActiveRecord::RecordNotFound exception will be raised as
described in the ticket).

I had a look at the patch in the ticket and amended it, so when the id
in nested attributes is set, I read the record from the db and create
the association in the join table. Unfortunately, creating the
association is not working properly.

here’s my code:
reflection =
self.class.reflect_on_association(association_name)
# fetch the record
record =
eval(“#{reflection.klass.name}.find(#{attributes[‘id’]})”)
if record.nil?
raise_nested_attributes_record_not_found(association_name,
attributes[‘id’])
end

      # create the association
      association.send(:add_record_to_target_with_callbacks, record)

unless association.loaded?
assign_to_or_mark_for_destruction(record, attributes,
options[:allow_destroy])

The last two lines doesn’t create the association. I looked at the
active record code but haven’t found a way to create the association
only. All the build/create/update methods will create a new record.

Would be nice if someone who’s familiar with the active record code
could help me out! Let me know if you need more information on this.

Thanks,
David

2

one more info:

the code above works when I create a new parent (and either create a
new child or choose an existing one in the nested form).

The code doesn’t work when I edit the model and choose an existing child
record (the association won’t be created), any hints?