Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Tree: 1a4bbaf106
Fetching contributors…

Cannot retrieve contributors at this time

570 lines (493 sloc) 18.907 kB
require 'active_support/core_ext/array/wrap'
module ActiveRecord
module Associations
# = Active Record Association Collection
#
# AssociationCollection is an abstract class that provides common stuff to
# ease the implementation of association proxies that represent
# collections. See the class hierarchy in AssociationProxy.
#
# You need to be careful with assumptions regarding the target: The proxy
# does not fetch records from the database until it needs them, but new
# ones created with +build+ are added to the target. So, the target may be
# non-empty and still lack children waiting to be read from the database.
# If you look directly to the database you cannot assume that's the entire
# collection because new records may have been added to the target, etc.
#
# If you need to work on all current children, new and existing records,
# +load_target+ and the +loaded+ flag are your friends.
class AssociationCollection < AssociationProxy #:nodoc:
delegate :group, :order, :limit, :joins, :where, :preload, :eager_load, :includes, :from, :lock, :readonly, :having, :to => :scoped
def select(select = nil)
if block_given?
load_target.select.each { |e| yield e }
else
scoped.select(select)
end
end
def find(*args)
if @reflection.options[:finder_sql]
find_by_scan(*args)
else
find_by_sql(*args)
end
end
# Fetches the first one using SQL if possible.
def first(*args)
if fetch_first_or_last_using_find?(args)
scoped.first(*args)
else
load_target unless loaded?
args.shift if args.first.kind_of?(Hash) && args.first.empty?
@target.first(*args)
end
end
# Fetches the last one using SQL if possible.
def last(*args)
if fetch_first_or_last_using_find?(args)
scoped.last(*args)
else
load_target unless loaded?
@target.last(*args)
end
end
def to_ary
load_target
if @target.is_a?(Array)
@target
else
Array.wrap(@target)
end
end
alias_method :to_a, :to_ary
def reset
reset_target!
reset_scopes_cache!
@loaded = false
end
def build(attributes = {}, &block)
if attributes.is_a?(Array)
attributes.collect { |attr| build(attr, &block) }
else
build_record(attributes) do |record|
block.call(record) if block_given?
set_owner_attributes(record)
end
end
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 if @owner.new_record?
transaction do
records.flatten.each do |record|
raise_on_type_mismatch(record)
add_record_to_target_with_callbacks(record) do |r|
result &&= insert_record(record) unless @owner.new_record?
end
end
end
result && self
end
alias_method :push, :<<
alias_method :concat, :<<
# Starts a transaction in the association class's database connection.
#
# class Author < ActiveRecord::Base
# has_many :books
# end
#
# Author.first.books.transaction do
# # same effect as calling Book.transaction
# end
def transaction(*args)
@reflection.klass.transaction(*args) do
yield
end
end
# Remove all records from this association
#
# See delete for more info.
def delete_all
load_target
delete(@target)
reset_target!
reset_scopes_cache!
end
# Calculate sum using SQL, not Enumerable
def sum(*args)
if block_given?
calculate(:sum, *args) { |*block_args| yield(*block_args) }
else
calculate(:sum, *args)
end
end
# Count all records using SQL. If the +:counter_sql+ or +:finder_sql+ option is set for the
# association, it will be used for the query. Otherwise, construct options and pass them with
# scope to the target class's +count+.
def count(column_name = nil, options = {})
column_name, options = nil, column_name if column_name.is_a?(Hash)
if @reflection.options[:counter_sql] || @reflection.options[:finder_sql]
unless options.blank?
raise ArgumentError, "If finder_sql/counter_sql is used then options cannot be passed"
end
@reflection.klass.count_by_sql(custom_counter_sql)
else
if @reflection.options[:uniq]
# This is needed because 'SELECT count(DISTINCT *)..' is not valid SQL.
column_name = "#{@reflection.quoted_table_name}.#{@reflection.klass.primary_key}" unless column_name
options.merge!(:distinct => true)
end
value = scoped.count(column_name, options)
limit = @reflection.options[:limit]
offset = @reflection.options[:offset]
if limit || offset
[ [value - offset.to_i, 0].max, limit.to_i ].min
else
value
end
end
end
# Removes +records+ from this association calling +before_remove+ and
# +after_remove+ callbacks.
#
# This method is abstract in the sense that +delete_records+ has to be
# provided by descendants. Note this method does not imply the records
# are actually removed from the database, that depends precisely on
# +delete_records+. They are in any case removed from the collection.
def delete(*records)
remove_records(records) do |_records, old_records|
delete_records(old_records) if old_records.any?
_records.each { |record| @target.delete(record) }
end
end
# Destroy +records+ and remove them from this association calling
# +before_remove+ and +after_remove+ callbacks.
#
# Note that this method will _always_ remove records from the database
# ignoring the +:dependent+ option.
def destroy(*records)
records = find(records) if records.any? {|record| record.kind_of?(Fixnum) || record.kind_of?(String)}
remove_records(records) do |_records, old_records|
old_records.each { |record| record.destroy }
end
load_target
end
# Removes all records from this association. Returns +self+ so method calls may be chained.
def clear
unless length.zero? # forces load_target if it hasn't happened already
if @reflection.options[:dependent] == :destroy
destroy_all
else
delete_all
end
end
self
end
# Destroy all the records from this association.
#
# See destroy for more info.
def destroy_all
load_target
destroy(@target).tap do
reset_target!
reset_scopes_cache!
end
end
def create(attrs = {})
if attrs.is_a?(Array)
attrs.collect { |attr| create(attr) }
else
create_record(attrs) do |record|
yield(record) if block_given?
insert_record(record, false)
end
end
end
def create!(attrs = {})
create_record(attrs) do |record|
yield(record) if block_given?
insert_record(record, true)
end
end
# Returns the size of the collection by executing a SELECT COUNT(*)
# query if the collection hasn't been loaded, and calling
# <tt>collection.size</tt> if it has.
#
# If the collection has been already loaded +size+ and +length+ are
# equivalent. If not and you are going to need the records anyway
# +length+ will take one less query. Otherwise +size+ is more efficient.
#
# This method is abstract in the sense that it relies on
# +count_records+, which is a method descendants have to provide.
def size
if @owner.new_record? || (loaded? && !@reflection.options[:uniq])
@target.size
elsif !loaded? && @reflection.options[:group]
load_target.size
elsif !loaded? && !@reflection.options[:uniq] && @target.is_a?(Array)
unsaved_records = @target.select { |r| r.new_record? }
unsaved_records.size + count_records
else
count_records
end
end
# Returns the size of the collection calling +size+ on the target.
#
# If the collection has been already loaded +length+ and +size+ are
# equivalent. If not and you are going to need the records anyway this
# method will take one less query. Otherwise +size+ is more efficient.
def length
load_target.size
end
# Equivalent to <tt>collection.size.zero?</tt>. If the collection has
# not been already loaded and you are going to fetch the records anyway
# it is better to check <tt>collection.length.zero?</tt>.
def empty?
size.zero?
end
def any?
if block_given?
method_missing(:any?) { |*block_args| yield(*block_args) }
else
!empty?
end
end
# Returns true if the collection has more than 1 record. Equivalent to collection.size > 1.
def many?
if block_given?
method_missing(:many?) { |*block_args| yield(*block_args) }
else
size > 1
end
end
def uniq(collection = self)
seen = {}
collection.find_all do |record|
seen[record.id] = true unless seen.key?(record.id)
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
transaction do
delete(@target - other_array)
unless concat(other_array - @target)
raise RecordNotSaved, "Failed to replace #{@reflection.name} because one or more of the "
"new records could not be saved."
end
end
end
def include?(record)
return false unless record.is_a?(@reflection.klass)
return include_in_memory?(record) if record.new_record?
load_target if @reflection.options[:finder_sql] && !loaded?
loaded? ? @target.include?(record) : exists?(record)
end
def respond_to?(method, include_private = false)
super || @reflection.klass.respond_to?(method, include_private)
end
def method_missing(method, *args, &block)
match = DynamicFinderMatch.match(method)
if match && match.creator?
attributes = match.attribute_names
return send(:"find_by_#{attributes.join('_and_')}", *args) || create(Hash[attributes.zip(args)])
end
if @target.respond_to?(method) || (!@reflection.klass.respond_to?(method) && Class.respond_to?(method))
super
elsif @reflection.klass.scopes[method]
@_scopes_cache ||= {}
@_scopes_cache[method] ||= {}
@_scopes_cache[method][args] ||= scoped.readonly(nil).send(method, *args)
else
scoped.readonly(nil).send(method, *args, &block)
end
end
protected
def association_scope
options = @reflection.options.slice(:order, :limit, :joins, :group, :having, :offset)
super.apply_finder_options(options)
end
def load_target
if find_target?
targets = []
begin
targets = find_target
rescue ActiveRecord::RecordNotFound
reset
end
@target = merge_target_lists(targets, @target)
end
loaded!
target
end
def add_record_to_target_with_callbacks(record)
callback(:before_add, record)
yield(record) if block_given?
@target ||= [] unless loaded?
if @reflection.options[:uniq] && index = @target.index(record)
@target[index] = record
else
@target << record
end
callback(:after_add, record)
set_inverse_instance(record)
record
end
private
def select_value
super || uniq_select_value
end
def uniq_select_value
@reflection.options[:uniq] && "DISTINCT #{@reflection.quoted_table_name}.*"
end
def custom_counter_sql
if @reflection.options[:counter_sql]
counter_sql = @reflection.options[:counter_sql]
else
# replace the SELECT clause with COUNT(*), preserving any hints within /* ... */
counter_sql = @reflection.options[:finder_sql].sub(/SELECT\b(\/\*.*?\*\/ )?(.*)\bFROM\b/im) { "SELECT #{$1}COUNT(*) FROM" }
end
interpolate_sql(counter_sql)
end
def custom_finder_sql
interpolate_sql(@reflection.options[:finder_sql])
end
def reset_target!
@target = []
end
def reset_scopes_cache!
@_scopes_cache = {}
end
def find_target
records =
if @reflection.options[:finder_sql]
@reflection.klass.find_by_sql(custom_finder_sql)
else
find(:all)
end
records = @reflection.options[:uniq] ? uniq(records) : records
records.each { |record| set_inverse_instance(record) }
records
end
def merge_target_lists(loaded, existing)
return loaded if existing.empty?
return existing if loaded.empty?
loaded.map do |f|
i = existing.index(f)
if i
existing.delete_at(i).tap do |t|
keys = ["id"] + t.changes.keys + (f.attribute_names - t.attribute_names)
# FIXME: this call to attributes causes many NoMethodErrors
attributes = f.attributes
(attributes.keys - keys).each do |k|
t.send("#{k}=", attributes[k])
end
end
else
f
end
end + existing
end
# Do the relevant stuff to insert the given record into the association collection. The
# force param specifies whether or not an exception should be raised on failure. The
# validate param specifies whether validation should be performed (if force is false).
def insert_record(record, force = true, validate = true)
raise NotImplementedError
end
def save_record(record, force, validate)
force ? record.save! : record.save(:validate => validate)
end
def create_record(attributes, &block)
ensure_owner_is_persisted!
transaction { build_record(attributes, &block) }
end
def build_record(attributes, &block)
attributes = scoped.scope_for_create.merge(attributes)
record = @reflection.build_association(attributes)
add_record_to_target_with_callbacks(record, &block)
end
def remove_records(*records)
records = records.flatten
records.each { |record| raise_on_type_mismatch(record) }
transaction do
records.each { |record| callback(:before_remove, record) }
old_records = records.reject { |r| r.new_record? }
yield(records, old_records)
records.each { |record| callback(:after_remove, record) }
end
end
def callback(method, record)
callbacks_for(method).each do |callback|
case callback
when Symbol
@owner.send(callback, record)
when Proc
callback.call(@owner, record)
else
callback.send(method, @owner, record)
end
end
end
def callbacks_for(callback_name)
full_callback_name = "#{callback_name}_for_#{@reflection.name}"
@owner.class.send(full_callback_name.to_sym) || []
end
def ensure_owner_is_persisted!
unless @owner.persisted?
raise ActiveRecord::RecordNotSaved, "You cannot call create unless the parent is saved"
end
end
# Should we deal with assoc.first or assoc.last by issuing an independent query to
# the database, or by getting the target, and then taking the first/last item from that?
#
# If the args is just a non-empty options hash, go to the database.
#
# Otherwise, go to the database only if none of the following are true:
# * target already loaded
# * owner is new record
# * custom :finder_sql exists
# * target contains new or changed record(s)
# * the first arg is an integer (which indicates the number of records to be returned)
def fetch_first_or_last_using_find?(args)
if args.first.kind_of?(Hash) && !args.first.empty?
true
else
!(loaded? ||
@owner.new_record? ||
@reflection.options[:finder_sql] ||
@target.any? { |record| record.new_record? || record.changed? } ||
args.first.kind_of?(Integer))
end
end
def include_in_memory?(record)
if @reflection.is_a?(ActiveRecord::Reflection::ThroughReflection)
@owner.send(proxy_reflection.through_reflection.name).any? { |source|
target = source.send(proxy_reflection.source_reflection.name)
target.respond_to?(:include?) ? target.include?(record) : target == record
} || @target.include?(record)
else
@target.include?(record)
end
end
# If using a custom finder_sql, #find scans the entire collection.
def find_by_scan(*args)
expects_array = args.first.kind_of?(Array)
ids = args.flatten.compact.uniq.map { |arg| arg.to_i }
if ids.size == 1
id = ids.first
record = load_target.detect { |r| id == r.id }
expects_array ? [ record ] : record
else
load_target.select { |r| ids.include?(r.id) }
end
end
def find_by_sql(*args)
scoped.find(*args)
end
end
end
end
Jump to Line
Something went wrong with that request. Please try again.