require 'set'
module ActiveRecord
module Associations
class AssociationCollection < AssociationProxy #:nodoc:
def to_ary
load_target
@target.to_ary
end
def reset
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 && self
end
alias_method :push, :<<
alias_method :concat, :<<
# Remove all records from this association
def delete_all
load_target
delete(@target)
reset_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 @reflection.options[:dependent] && @reflection.options[:dependent] == :delete_all
destroy_all
else
delete_all
end
self
end
def destroy_all
@owner.transaction do
each { |record| record.destroy }
end
reset_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? && !@reflection.options[:uniq] 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)
seen = Set.new
collection.inject([]) do |kept, record|
unless seen.include?(record.id)
kept << record
seen << record.id
end
kept
end
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
protected
def reset_target!
@target = Array.new
end
def find_target
records =
if @reflection.options[:finder_sql]
@reflection.klass.find_by_sql(@finder_sql)
else
find(:all)
end
@reflection.options[:uniq] ? uniq(records) : records
end
private
# 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}_for_#{@reflection.name}"
@owner.class.read_inheritable_attribute(full_callback_name.to_sym) || []
end
end
end
end