diff options
Diffstat (limited to 'activerecord/lib/active_record/associations.rb')
| -rw-r--r-- | activerecord/lib/active_record/associations.rb | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb index 860e76fa18..727ee5f65f 100644 --- a/activerecord/lib/active_record/associations.rb +++ b/activerecord/lib/active_record/associations.rb @@ -4,6 +4,12 @@ require 'active_support/core_ext/module/remove_method' require 'active_record/errors' module ActiveRecord + class AssociationNotFoundError < ConfigurationError #:nodoc: + def initialize(record, association_name) + super("Association named '#{association_name}' was not found on #{record.class.name}; perhaps you misspelled it?") + end + end + class InverseOfAssociationNotFoundError < ActiveRecordError #:nodoc: def initialize(reflection, associated_class = nil) super("Could not find the inverse association for #{reflection.name} (#{reflection.options[:inverse_of].inspect} in #{associated_class.nil? ? reflection.class_name : associated_class.name})") @@ -145,7 +151,7 @@ module ActiveRecord association = association_instance_get(name) if association.nil? - reflection = self.class.reflect_on_association(name) + raise AssociationNotFoundError.new(self, name) unless reflection = self.class.reflect_on_association(name) association = reflection.association_class.new(self, reflection) association_instance_set(name, association) end @@ -413,6 +419,10 @@ module ActiveRecord # has_many :birthday_events, ->(user) { where starts_on: user.birthday }, class_name: 'Event' # end # + # Note: Joining, eager loading and preloading of these associations is not fully possible. + # These operations happen before instance creation and the scope will be called with a +nil+ argument. + # This can lead to unexpected behavior and is deprecated. + # # == Association callbacks # # Similar to the normal callbacks that hook into the life cycle of an Active Record object, @@ -767,11 +777,16 @@ module ActiveRecord # like this can have unintended consequences. # In the above example posts with no approved comments are not returned at all, because # the conditions apply to the SQL statement as a whole and not just to the association. + # # You must disambiguate column references for this fallback to happen, for example # <tt>order: "author.name DESC"</tt> will work but <tt>order: "name DESC"</tt> will not. # - # If you do want eager load only some members of an association it is usually more natural - # to include an association which has conditions defined on it: + # If you want to load all posts (including posts with no approved comments) then write + # your own LEFT OUTER JOIN query using ON + # + # Post.joins("LEFT OUTER JOIN comments ON comments.post_id = posts.id AND comments.approved = '1'") + # + # In this case it is usually more natural to include an association which has conditions defined on it: # # class Post < ActiveRecord::Base # has_many :approved_comments, -> { where approved: true }, class_name: 'Comment' @@ -1565,6 +1580,11 @@ module ActiveRecord join_model = builder.through_model + # FIXME: we should move this to the internal constants. Also people + # should never directly access this constant so I'm not happy about + # setting it. + const_set join_model.name, join_model + middle_reflection = builder.middle_reflection join_model Builder::HasMany.define_callbacks self, middle_reflection @@ -1584,7 +1604,7 @@ module ActiveRecord hm_options[:through] = middle_reflection.name hm_options[:source] = join_model.right_reflection.name - [:before_add, :after_add, :before_remove, :after_remove, :autosave, :validate].each do |k| + [:before_add, :after_add, :before_remove, :after_remove, :autosave, :validate, :join_table].each do |k| hm_options[k] = options[k] if options.key? k end |