accepts_nested_attributes_for & :reject_if. How to prevent rejection until parent association saves?
class Gift < ActiveRecord::Base
has_many :contributions
accepts_nested_attributes_for :contributions, :reject_if => proc { |a| a['amount'].blank? }
Contribution has a :nickname attribute. In the :new form, it is p开发者_如何学运维re-populated with the user's real name. A user might decide to change it to "Uncle Bob" (or whatever). Unfortunately, with :reject_if, if no amount is specified in the contribution, the :nickname change is lost when :new reloads in cases where @gift is not valid. This happens because the nested contribution_attributes are rejected. How do we preserve the :nickname change and only handle the rejection when @gift is actually saved?
class Gift < ActiveRecord::Base
has_many :contributions
accepts_nested_attributes_for :contributions,
:reject_if => proc { |a| a['amount'].blank? }
end
class Contribution < ActiveRecord::Base
belongs_to :gift
validates_presence_of :nickname, :amount
end
...in the gift form...
f.text_field :nickname, :value => (params[:gift][:contributions_attributes]['0'][:nickname] rescue @m.full_name)
This preserves :nickname changes through failed validations and still discards a nested contributions that contain :nickname only.
I think you're looking for a validation in the Contribution model instead of a :reject_if clause.
:reject_if will throw away the entire record if the condition is met. Failed validations in the contribution model will block the associated gift from being saved. However @gift will retain the contribution regardless of its amount value on a failed save, allowing your user the chance to correct it, when the controller renders the new action again.
The solution is to remove the :reject_if clause from the accepts_nested_attributes_for statement, and add validates_presence_of_amount in the Contributions model.
class Gift < ActiveRecord::Base
has_many :contributions
accepts_nested_attributes_for :contributions
...
end
class Contribution < ActiveRecord::Base
validates_presence_of :amount
...
end
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