diff options
Diffstat (limited to 'activerecord/lib')
5 files changed, 117 insertions, 18 deletions
diff --git a/activerecord/lib/active_record/associations/builder/has_many.rb b/activerecord/lib/active_record/associations/builder/has_many.rb index 0d1bdd21ee..429def5455 100644 --- a/activerecord/lib/active_record/associations/builder/has_many.rb +++ b/activerecord/lib/active_record/associations/builder/has_many.rb @@ -5,7 +5,7 @@ module ActiveRecord::Associations::Builder end def valid_options - super + [:primary_key, :dependent, :as, :through, :source, :source_type, :inverse_of, :counter_cache] + super + [:primary_key, :dependent, :as, :through, :source, :source_type, :inverse_of, :automatic_inverse_of, :counter_cache] end def valid_dependent_options diff --git a/activerecord/lib/active_record/associations/builder/singular_association.rb b/activerecord/lib/active_record/associations/builder/singular_association.rb index 6a5830e57f..f06426a09d 100644 --- a/activerecord/lib/active_record/associations/builder/singular_association.rb +++ b/activerecord/lib/active_record/associations/builder/singular_association.rb @@ -1,7 +1,7 @@ module ActiveRecord::Associations::Builder class SingularAssociation < Association #:nodoc: def valid_options - super + [:remote, :dependent, :counter_cache, :primary_key, :inverse_of] + super + [:remote, :dependent, :counter_cache, :primary_key, :inverse_of, :automatic_inverse_of] end def constructable? diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb index 021832de46..8bdaeef924 100644 --- a/activerecord/lib/active_record/nested_attributes.rb +++ b/activerecord/lib/active_record/nested_attributes.rb @@ -305,6 +305,11 @@ module ActiveRecord reflection.options[:autosave] = true add_autosave_association_callbacks(reflection) + # Clear cached values of any inverse associations found in the + # reflection and prevent the reflection from finding inverses + # automatically in the future. + reflection.remove_automatic_inverse_of! + nested_attributes_options = self.nested_attributes_options.dup nested_attributes_options[association_name.to_sym] = options self.nested_attributes_options = nested_attributes_options diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb index 60eda96f08..0ba860a186 100644 --- a/activerecord/lib/active_record/reflection.rb +++ b/activerecord/lib/active_record/reflection.rb @@ -181,6 +181,7 @@ module ActiveRecord def initialize(*args) super @collection = [:has_many, :has_and_belongs_to_many].include?(macro) + @automatic_inverse_of = nil end # Returns a new, unsaved instance of the associated class. +attributes+ will @@ -289,15 +290,32 @@ module ActiveRecord alias :source_macro :macro def has_inverse? - @options[:inverse_of] + @options[:inverse_of] || find_inverse_of_automatically end def inverse_of - if has_inverse? - @inverse_of ||= klass.reflect_on_association(options[:inverse_of]) + @inverse_of ||= if options[:inverse_of] + klass.reflect_on_association(options[:inverse_of]) + else + find_inverse_of_automatically end end + # Clears the cached value of +@inverse_of+ on this object. This will + # not remove the :inverse_of option however, so future calls on the + # +inverse_of+ will have to recompute the inverse. + def clear_inverse_of_cache! + @inverse_of = nil + end + + # Removes the cached inverse association that was found automatically + # and prevents this object from finding the inverse association + # automatically in the future. + def remove_automatic_inverse_of! + @automatic_inverse_of = nil + options[:automatic_inverse_of] = false + end + def polymorphic_inverse_of(associated_class) if has_inverse? if inverse_relationship = associated_class.reflect_on_association(options[:inverse_of]) @@ -366,7 +384,84 @@ module ActiveRecord options.key? :polymorphic end + VALID_AUTOMATIC_INVERSE_MACROS = [:has_many, :has_one, :belongs_to] + INVALID_AUTOMATIC_INVERSE_OPTIONS = [:conditions, :through, :polymorphic, :foreign_key] + private + # Attempts to find the inverse association automatically. + # If it cannot find a suitable inverse association, it returns + # nil. + def find_inverse_of_automatically + if @automatic_inverse_of == false + nil + elsif @automatic_inverse_of.nil? + set_automatic_inverse_of + else + klass.reflect_on_association(@automatic_inverse_of) + end + end + + # Sets the +@automatic_inverse_of+ instance variable, and returns + # either nil or the inverse association that it finds. + # + # This method caches the inverse association that is found so that + # future calls to +find_inverse_of_automatically+ have much less + # overhead. + def set_automatic_inverse_of + if can_find_inverse_of_automatically?(self) + inverse_name = active_record.name.downcase.to_sym + + begin + reflection = klass.reflect_on_association(inverse_name) + rescue NameError + # Give up: we couldn't compute the klass type so we won't be able + # to find any associations either. + reflection = false + end + + if valid_inverse_reflection?(reflection) + @automatic_inverse_of = inverse_name + reflection + else + @automatic_inverse_of = false + nil + end + else + @automatic_inverse_of = false + nil + end + end + + # Checks if the inverse reflection that is returned from the + # +set_automatic_inverse_of+ method is a valid reflection. We must + # make sure that the reflection's active_record name matches up + # with the current reflection's klass name. + # + # Note: klass will always be valid because when there's a NameError + # from calling +klass+, +reflection+ will already be set to false. + def valid_inverse_reflection?(reflection) + reflection && + klass.name == reflection.active_record.try(:name) && + klass.primary_key == reflection.active_record_primary_key && + can_find_inverse_of_automatically?(reflection) + end + + # Checks to see if the reflection doesn't have any options that prevent + # us from being able to guess the inverse automatically. First, the + # +automatic_inverse_of+ option cannot be set to false. Second, we must + # have :has_many, :has_one, :belongs_to associations. Third, we must + # not have options such as :class_name or :polymorphic which prevent us + # from correctly guessing the inverse association. + # + # Anything with a scope can additionally ruin our attempt at finding an + # inverse, so we exclude reflections with scopes. + def can_find_inverse_of_automatically?(reflection) + reflection.options[:automatic_inverse_of] != false && + VALID_AUTOMATIC_INVERSE_MACROS.include?(reflection.macro) && + !INVALID_AUTOMATIC_INVERSE_OPTIONS.any? { |opt| reflection.options[opt] } && + !reflection.scope + end + def derive_class_name class_name = name.to_s.camelize class_name = class_name.singularize if collection? diff --git a/activerecord/lib/active_record/relation/merger.rb b/activerecord/lib/active_record/relation/merger.rb index 936b83261e..bda7a76330 100644 --- a/activerecord/lib/active_record/relation/merger.rb +++ b/activerecord/lib/active_record/relation/merger.rb @@ -139,21 +139,20 @@ module ActiveRecord if values[:where].empty? || relation.where_values.empty? relation.where_values + values[:where] else - # Remove equalities from the existing relation with a LHS which is - # present in the relation being merged in. + sanitized_wheres + values[:where] + end + end - seen = Set.new - values[:where].each { |w| - if w.respond_to?(:operator) && w.operator == :== - seen << w.left - end - } + # Remove equalities from the existing relation with a LHS which is + # present in the relation being merged in. + def sanitized_wheres + seen = Set.new + values[:where].each do |w| + seen << w.left if w.respond_to?(:operator) && w.operator == :== + end - relation.where_values.reject { |w| - w.respond_to?(:operator) && - w.operator == :== && - seen.include?(w.left) - } + values[:where] + relation.where_values.reject do |w| + w.respond_to?(:operator) && w.operator == :== && seen.include?(w.left) end end end |