Module: AttributeFu::Associations::ClassMethods

Defined in:
lib/attribute_fu/associations.rb

Instance Method Summary collapse

Instance Method Details

#has_many_with_association_option(association_id, options = {}, &extension) ⇒ Object

Behaves identically to the regular has_many, except adds the option :attributes, which, if true, creates a method called association_id_attributes (i.e. task_attributes, or comment_attributes) for setting the attributes of a collection of associated models.

It also adds the option :discard_if, which accepts a proc or a symbol. If the proc evaluates to true, the child model will be discarded. The symbol is sent as a message to the child model instance; if it returns true, the child model will be discarded.

e.g.

:discard_if => proc { |comment| comment.title.blank? }
  or
:discard_if => :blank? # where blank is defined in Comment

The format is as follows:

@project.task_attributes = {
  @project.tasks.first.id => {:title => "A new title for an existing task"},
  :new => {
    "0" => {:title => "A new task"}
  }
}

Any existing tasks that are not present in the attributes hash will be removed from the association when the (parent) model is saved.



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# File 'lib/attribute_fu/associations.rb', line 111

def has_many_with_association_option(association_id, options = {}, &extension)
  unless (config = options.delete(:attributes)).nil?
    managed_association_attributes[association_id] = {}
    if options.has_key?(:discard_if)
      discard_if = options.delete(:discard_if)
      discard_if = discard_if.to_proc if discard_if.is_a?(Symbol)
      managed_association_attributes[association_id][:discard_if] = discard_if
    end
    collection_with_attributes_writer(association_id)
  end
  
  has_many_without_association_option(association_id, options, &extension)
end