method

assign_nested_attributes_for_collection_association

v4.2.1 - Show latest stable - Class: ActiveRecord::NestedAttributes

assign_nested_attributes_for_collection_association(association_name, attributes_collection)

private

Assigns the given attributes to the collection association.

Hashes with an :id value matching an existing associated record will update that record. Hashes without an :id value will build a new record for the association. Hashes with a matching :id value and a :_destroy key set to a truthy value will mark the matched record for destruction.

For example:

assign_nested_attributes_for_collection_association(:people, {
  '1' => { id: '1', name: 'Peter' },
  '2' => { name: 'John' },
  '3' => { id: '2', _destroy: true }
})

Will update the name of the Person with ID 1, build a new associated person with the name ‘John’, and mark the associated Person with ID 2 for destruction.

Also accepts an Array of attribute hashes:

assign_nested_attributes_for_collection_association(:people, [
  { id: '1', name: 'Peter' },
  { name: 'John' },
  { id: '2', _destroy: true }
])

# File activerecord/lib/active_record/nested_attributes.rb, line 433
    def assign_nested_attributes_for_collection_association(association_name, attributes_collection)
      options = self.nested_attributes_options[association_name]

      unless attributes_collection.is_a?(Hash) || attributes_collection.is_a?(Array)
        raise ArgumentError, "Hash or Array expected, got #{attributes_collection.class.name} (#{attributes_collection.inspect})"
      end

      check_record_limit!(options[:limit], attributes_collection)

      if attributes_collection.is_a? Hash
        keys = attributes_collection.keys
        attributes_collection = if keys.include?('id') || keys.include?(:id)
          [attributes_collection]
        else
          attributes_collection.values
        end
      end

      association = association(association_name)

      existing_records = if association.loaded?
        association.target
      else
        attribute_ids = attributes_collection.map {|a| a['id'] || a[:id] }.compact
        attribute_ids.empty? ? [] : association.scope.where(association.klass.primary_key => attribute_ids)
      end

      attributes_collection.each do |attributes|
        attributes = attributes.with_indifferent_access

        if attributes['id'].blank?
          unless reject_new_record?(association_name, attributes)
            association.build(attributes.except(*UNASSIGNABLE_KEYS))
          end
        elsif existing_record = existing_records.detect { |record| record.id.to_s == attributes['id'].to_s }
          unless call_reject_if(association_name, attributes)
            # Make sure we are operating on the actual object which is in the association's
            # proxy_target array (either by finding it, or adding it if not found)
            # Take into account that the proxy_target may have changed due to callbacks
            target_record = association.target.detect { |record| record.id.to_s == attributes['id'].to_s }
            if target_record
              existing_record = target_record
            else
              association.add_to_target(existing_record, :skip_callbacks)
            end

            assign_to_or_mark_for_destruction(existing_record, attributes, options[:allow_destroy])
          end
        else
          raise_nested_attributes_record_not_found!(association_name, attributes['id'])
        end
      end
    end

assign_nested_attributes_for_collection_association

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