method

construct_id_map

v2.3.8 - Show latest stable - Class: ActiveRecord::AssociationPreload::ClassMethods

construct_id_map(records, primary_key=nil)

private

Given a collection of ActiveRecord objects, constructs a Hash which maps the objects’ IDs to the relevant objects. Returns a 2-tuple (id_to_record_map, ids) where id_to_record_map is the Hash, and ids is an Array of record IDs.

# File activerecord/lib/active_record/association_preload.rb, line 171
      def construct_id_map(records, primary_key=nil)
        id_to_record_map = {}
        ids = []
        records.each do |record|
          primary_key ||= record.class.primary_key
          ids << record[primary_key]
          mapped_records = (id_to_record_map[ids.last.to_s] ||= [])
          mapped_records << record
        end
        ids.uniq!
        return id_to_record_map, ids
      end

construct_id_map

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