require 'set' module ActiveRecord module Associations class AssociationCollection < AssociationProxy #:nodoc: def to_ary load_target @target.to_ary end def reset @target = [] @loaded = false end # Add +records+ to this association. Returns +self+ so method calls may be chained. # Since << flattens its argument list and inserts each record, +push+ and +concat+ behave identically. def <<(*records) result = true load_target @owner.transaction do flatten_deeper(records).each do |record| raise_on_type_mismatch(record) callback(:before_add, record) result &&= insert_record(record) unless @owner.new_record? @target << record callback(:after_add, record) end end result and self end alias_method :push, :<< alias_method :concat, :<< # Remove all records from this association def delete_all delete(@target) @target = [] end # Remove +records+ from this association. Does not destroy +records+. def delete(*records) records = flatten_deeper(records) records.each { |record| raise_on_type_mismatch(record) } records.reject! { |record| @target.delete(record) if record.new_record? } return if records.empty? @owner.transaction do records.each { |record| callback(:before_remove, record) } delete_records(records) records.each do |record| @target.delete(record) callback(:after_remove, record) end end end # Removes all records from this association. Returns +self+ so method calls may be chained. def clear return self if length.zero? # forces load_target if hasn't happened already if @options[:exclusively_dependent] destroy_all else delete_all end self end def destroy_all @owner.transaction do each { |record| record.destroy } end @target = [] end def create(attributes = {}) # Can't use Base.create since the foreign key may be a protected attribute. if attributes.is_a?(Array) attributes.collect { |attr| create(attr) } else record = build(attributes) record.save unless @owner.new_record? record end end # Returns the size of the collection by executing a SELECT COUNT(*) query if the collection hasn't been loaded and # calling collection.size if it has. If it's more likely than not that the collection does have a size larger than zero # and you need to fetch that collection afterwards, it'll take one less SELECT query if you use length. def size if loaded? then @target.size else count_records end end # Returns the size of the collection by loading it and calling size on the array. If you want to use this method to check # whether the collection is empty, use collection.length.zero? instead of collection.empty? def length load_target.size end def empty? size.zero? end def uniq(collection = self) collection.inject([]) { |uniq_records, record| uniq_records << record unless uniq_records.include?(record); uniq_records } end # Replace this collection with +other_array+ # This will perform a diff and delete/add only records that have changed. def replace(other_array) other_array.each { |val| raise_on_type_mismatch(val) } load_target other = other_array.size < 100 ? other_array : other_array.to_set current = @target.size < 100 ? @target : @target.to_set @owner.transaction do delete(@target.select { |v| !other.include?(v) }) concat(other_array.select { |v| !current.include?(v) }) end end private def raise_on_type_mismatch(record) raise ActiveRecord::AssociationTypeMismatch, "#{@association_class} expected, got #{record.class}" unless record.is_a?(@association_class) end def target_obsolete? false end # Array#flatten has problems with recursive arrays. Going one level deeper solves the majority of the problems. def flatten_deeper(array) array.collect { |element| element.respond_to?(:flatten) ? element.flatten : element }.flatten end def callback(method, record) callbacks_for(method).each do |callback| case callback when Symbol @owner.send(callback, record) when Proc, Method callback.call(@owner, record) else if callback.respond_to?(method) callback.send(method, @owner, record) else raise ActiveRecordError, "Callbacks must be a symbol denoting the method to call, a string to be evaluated, a block to be invoked, or an object responding to the callback method." end end end end def callbacks_for(callback_name) full_callback_name = "#{callback_name.to_s}_for_#{@association_name.to_s}" @owner.class.read_inheritable_attribute(full_callback_name.to_sym) or [] end end end end