--- /dev/null
+require 'set'
+
+module ActiveRecord
+ module Associations
+ # 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 beed 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:
+ def initialize(owner, reflection)
+ super
+ construct_sql
+ end
+
+ def find(*args)
+ options = args.extract_options!
+
+ # If using a custom finder_sql, scan the entire collection.
+ if @reflection.options[:finder_sql]
+ 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
+ else
+ conditions = "#{@finder_sql}"
+ if sanitized_conditions = sanitize_sql(options[:conditions])
+ conditions << " AND (#{sanitized_conditions})"
+ end
+
+ options[:conditions] = conditions
+
+ if options[:order] && @reflection.options[:order]
+ options[:order] = "#{options[:order]}, #{@reflection.options[:order]}"
+ elsif @reflection.options[:order]
+ options[:order] = @reflection.options[:order]
+ end
+
+ # Build options specific to association
+ construct_find_options!(options)
+
+ merge_options_from_reflection!(options)
+
+ # Pass through args exactly as we received them.
+ args << options
+ @reflection.klass.find(*args)
+ end
+ end
+
+ # Fetches the first one using SQL if possible.
+ def first(*args)
+ if fetch_first_or_last_using_find?(args)
+ find(:first, *args)
+ else
+ load_target unless loaded?
+ @target.first(*args)
+ end
+ end
+
+ # Fetches the last one using SQL if possible.
+ def last(*args)
+ if fetch_first_or_last_using_find?(args)
+ find(:last, *args)
+ else
+ load_target unless loaded?
+ @target.last(*args)
+ end
+ end
+
+ def to_ary
+ load_target
+ @target.to_ary
+ end
+
+ def reset
+ reset_target!
+ @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_belongs_to_association_for(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
+ flatten_deeper(records).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.find(: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
+ def delete_all
+ load_target
+ delete(@target)
+ reset_target!
+ 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+ option is set for the association, it will
+ # be used for the query. If no +:counter_sql+ was supplied, but +:finder_sql+ was set, the
+ # descendant's +construct_sql+ method will have set :counter_sql automatically.
+ # Otherwise, construct options and pass them with scope to the target class's +count+.
+ def count(*args)
+ if @reflection.options[:counter_sql]
+ @reflection.klass.count_by_sql(@counter_sql)
+ else
+ column_name, options = @reflection.klass.send(:construct_count_options_from_args, *args)
+ 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}" if column_name == :all
+ options.merge!(:distinct => true)
+ end
+
+ value = @reflection.klass.send(:with_scope, construct_scope) { @reflection.klass.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)
+ records = flatten_deeper(records)
+ 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? }
+ delete_records(old_records) if old_records.any?
+
+ 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 it hasn't happened already
+
+ if @reflection.options[:dependent] && @reflection.options[:dependent] == :destroy
+ destroy_all
+ else
+ delete_all
+ end
+
+ self
+ end
+
+ def destroy_all
+ transaction do
+ each { |record| record.destroy }
+ end
+
+ reset_target!
+ 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?
+ record.save
+ end
+ end
+ end
+
+ def create!(attrs = {})
+ create_record(attrs) do |record|
+ yield(record) if block_given?
+ record.save!
+ 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
+
+ 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
+
+ transaction do
+ delete(@target.select { |v| !other.include?(v) })
+ concat(other_array.select { |v| !current.include?(v) })
+ end
+ end
+
+ def include?(record)
+ return false unless record.is_a?(@reflection.klass)
+ load_target if @reflection.options[:finder_sql] && !loaded?
+ return @target.include?(record) if loaded?
+ exists?(record)
+ end
+
+ def proxy_respond_to?(method, include_private = false)
+ super || @reflection.klass.respond_to?(method, include_private)
+ end
+
+ protected
+ def construct_find_options!(options)
+ end
+
+ def load_target
+ if !@owner.new_record? || foreign_key_present
+ begin
+ if !loaded?
+ if @target.is_a?(Array) && @target.any?
+ @target = find_target + @target.find_all {|t| t.new_record? }
+ else
+ @target = find_target
+ end
+ end
+ rescue ActiveRecord::RecordNotFound
+ reset
+ end
+ end
+
+ loaded if target
+ target
+ end
+
+ def method_missing(method, *args)
+ if @target.respond_to?(method) || (!@reflection.klass.respond_to?(method) && Class.respond_to?(method))
+ if block_given?
+ super { |*block_args| yield(*block_args) }
+ else
+ super
+ end
+ elsif @reflection.klass.scopes.include?(method)
+ @reflection.klass.scopes[method].call(self, *args)
+ else
+ with_scope(construct_scope) do
+ if block_given?
+ @reflection.klass.send(method, *args) { |*block_args| yield(*block_args) }
+ else
+ @reflection.klass.send(method, *args)
+ end
+ end
+ end
+ end
+
+ # overloaded in derived Association classes to provide useful scoping depending on association type.
+ def construct_scope
+ {}
+ end
+
+ 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
+
+ def create_record(attrs)
+ attrs.update(@reflection.options[:conditions]) if @reflection.options[:conditions].is_a?(Hash)
+ ensure_owner_is_not_new
+ record = @reflection.klass.send(:with_scope, :create => construct_scope[:create]) do
+ @reflection.build_association(attrs)
+ end
+ if block_given?
+ add_record_to_target_with_callbacks(record) { |*block_args| yield(*block_args) }
+ else
+ add_record_to_target_with_callbacks(record)
+ end
+ end
+
+ def build_record(attrs)
+ attrs.update(@reflection.options[:conditions]) if @reflection.options[:conditions].is_a?(Hash)
+ record = @reflection.build_association(attrs)
+ if block_given?
+ add_record_to_target_with_callbacks(record) { |*block_args| yield(*block_args) }
+ else
+ add_record_to_target_with_callbacks(record)
+ end
+ end
+
+ def add_record_to_target_with_callbacks(record)
+ callback(:before_add, record)
+ yield(record) if block_given?
+ @target ||= [] unless loaded?
+ @target << record unless @reflection.options[:uniq] && @target.include?(record)
+ callback(:after_add, record)
+ record
+ end
+
+ def callback(method, record)
+ callbacks_for(method).each do |callback|
+ ActiveSupport::Callbacks::Callback.new(method, callback, record).call(@owner, record)
+ 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
+
+ def ensure_owner_is_not_new
+ if @owner.new_record?
+ raise ActiveRecord::RecordNotSaved, "You cannot call create unless the parent is saved"
+ end
+ end
+
+ def fetch_first_or_last_using_find?(args)
+ args.first.kind_of?(Hash) || !(loaded? || @owner.new_record? || @reflection.options[:finder_sql] ||
+ @target.any? { |record| record.new_record? } || args.first.kind_of?(Integer))
+ end
+ end
+ end
+end
projects / depot.git / blobdiff