diff options
Diffstat (limited to 'activerecord/lib')
18 files changed, 533 insertions, 439 deletions
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb index e91cbd7f33..08fb6bf3c4 100644 --- a/activerecord/lib/active_record/associations.rb +++ b/activerecord/lib/active_record/associations.rb @@ -52,14 +52,6 @@ module ActiveRecord end end - class HasManyThroughSourceAssociationMacroError < ActiveRecordError #:nodoc: - def initialize(reflection) - through_reflection = reflection.through_reflection - source_reflection = reflection.source_reflection - super("Invalid source reflection macro :#{source_reflection.macro}#{" :through" if source_reflection.options[:through]} for has_many #{reflection.name.inspect}, :through => #{through_reflection.name.inspect}. Use :source to specify the source reflection.") - end - end - class HasManyThroughCantAssociateThroughHasOneOrManyReflection < ActiveRecordError #:nodoc: def initialize(owner, reflection) super("Cannot modify association '#{owner.class.name}##{reflection.name}' because the source reflection class '#{reflection.source_reflection.class_name}' is associated to '#{reflection.through_reflection.class_name}' via :#{reflection.source_reflection.macro}.") @@ -78,6 +70,12 @@ module ActiveRecord end end + class HasManyThroughNestedAssociationsAreReadonly < ActiveRecordError #:nodoc + def initialize(owner, reflection) + super("Cannot modify association '#{owner.class.name}##{reflection.name}' because it goes through more than one other association.") + end + end + class HasAndBelongsToManyAssociationWithPrimaryKeyError < ActiveRecordError #:nodoc: def initialize(reflection) super("Primary key is not allowed in a has_and_belongs_to_many join table (#{reflection.options[:join_table]}).") @@ -142,8 +140,11 @@ module ActiveRecord autoload :HasAndBelongsToMany, 'active_record/associations/builder/has_and_belongs_to_many' end - autoload :Preloader, 'active_record/associations/preloader' - autoload :JoinDependency, 'active_record/associations/join_dependency' + autoload :Preloader, 'active_record/associations/preloader' + autoload :JoinDependency, 'active_record/associations/join_dependency' + autoload :AssociationScope, 'active_record/associations/association_scope' + autoload :AliasTracker, 'active_record/associations/alias_tracker' + autoload :JoinHelper, 'active_record/associations/join_helper' # Clears out the association cache. def clear_association_cache #:nodoc: @@ -548,6 +549,49 @@ module ActiveRecord # belongs_to :tag, :inverse_of => :taggings # end # + # === Nested Associations + # + # You can actually specify *any* association with the <tt>:through</tt> option, including an + # association which has a <tt>:through</tt> option itself. For example: + # + # class Author < ActiveRecord::Base + # has_many :posts + # has_many :comments, :through => :posts + # has_many :commenters, :through => :comments + # end + # + # class Post < ActiveRecord::Base + # has_many :comments + # end + # + # class Comment < ActiveRecord::Base + # belongs_to :commenter + # end + # + # @author = Author.first + # @author.commenters # => People who commented on posts written by the author + # + # An equivalent way of setting up this association this would be: + # + # class Author < ActiveRecord::Base + # has_many :posts + # has_many :commenters, :through => :posts + # end + # + # class Post < ActiveRecord::Base + # has_many :comments + # has_many :commenters, :through => :comments + # end + # + # class Comment < ActiveRecord::Base + # belongs_to :commenter + # end + # + # When using nested association, you will not be able to modify the association because there + # is not enough information to know what modification to make. For example, if you tried to + # add a <tt>Commenter</tt> in the example above, there would be no way to tell how to set up the + # intermediate <tt>Post</tt> and <tt>Comment</tt> objects. + # # === Polymorphic Associations # # Polymorphic associations on models are not restricted on what types of models they @@ -1068,10 +1112,10 @@ module ActiveRecord # [:as] # Specifies a polymorphic interface (See <tt>belongs_to</tt>). # [:through] - # Specifies a join model through which to perform the query. Options for <tt>:class_name</tt>, + # Specifies an association through which to perform the query. This can be any other type + # of association, including other <tt>:through</tt> associations. Options for <tt>:class_name</tt>, # <tt>:primary_key</tt> and <tt>:foreign_key</tt> are ignored, as the association uses the - # source reflection. You can only use a <tt>:through</tt> query through a <tt>belongs_to</tt>, - # <tt>has_one</tt> or <tt>has_many</tt> association on the join model. + # source reflection. # # If the association on the join model is a +belongs_to+, the collection can be modified # and the records on the <tt>:through</tt> model will be automatically created and removed @@ -1198,10 +1242,10 @@ module ActiveRecord # you want to do a join but not include the joined columns. Do not forget to include the # primary and foreign keys, otherwise it will raise an error. # [:through] - # Specifies a Join Model through which to perform the query. Options for <tt>:class_name</tt> - # and <tt>:foreign_key</tt> are ignored, as the association uses the source reflection. You - # can only use a <tt>:through</tt> query through a <tt>has_one</tt> or <tt>belongs_to</tt> - # association on the join model. + # Specifies a Join Model through which to perform the query. Options for <tt>:class_name</tt>, + # <tt>:primary_key</tt>, and <tt>:foreign_key</tt> are ignored, as the association uses the + # source reflection. You can only use a <tt>:through</tt> query through a <tt>has_one</tt> + # or <tt>belongs_to</tt> association on the join model. # [:source] # Specifies the source association name used by <tt>has_one :through</tt> queries. # Only use it if the name cannot be inferred from the association. diff --git a/activerecord/lib/active_record/associations/alias_tracker.rb b/activerecord/lib/active_record/associations/alias_tracker.rb new file mode 100644 index 0000000000..634dee2289 --- /dev/null +++ b/activerecord/lib/active_record/associations/alias_tracker.rb @@ -0,0 +1,85 @@ +require 'active_support/core_ext/string/conversions' + +module ActiveRecord + module Associations + # Keeps track of table aliases for ActiveRecord::Associations::ClassMethods::JoinDependency and + # ActiveRecord::Associations::ThroughAssociationScope + class AliasTracker # :nodoc: + attr_reader :aliases, :table_joins + + # table_joins is an array of arel joins which might conflict with the aliases we assign here + def initialize(table_joins = []) + @aliases = Hash.new + @table_joins = table_joins + end + + def aliased_table_for(table_name, aliased_name = nil) + table_alias = aliased_name_for(table_name, aliased_name) + + if table_alias == table_name + Arel::Table.new(table_name) + else + Arel::Table.new(table_name).alias(table_alias) + end + end + + def aliased_name_for(table_name, aliased_name = nil) + aliased_name ||= table_name + + initialize_count_for(table_name) if aliases[table_name].nil? + + if aliases[table_name].zero? + # If it's zero, we can have our table_name + aliases[table_name] = 1 + table_name + else + # Otherwise, we need to use an alias + aliased_name = connection.table_alias_for(aliased_name) + + initialize_count_for(aliased_name) if aliases[aliased_name].nil? + + # Update the count + aliases[aliased_name] += 1 + + if aliases[aliased_name] > 1 + "#{truncate(aliased_name)}_#{aliases[aliased_name]}" + else + aliased_name + end + end + end + + def pluralize(table_name) + ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name + end + + private + + def initialize_count_for(name) + aliases[name] = 0 + + unless Arel::Table === table_joins + # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase + quoted_name = connection.quote_table_name(name).downcase + + aliases[name] += table_joins.map { |join| + # Table names + table aliases + join.left.downcase.scan( + /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/ + ).size + }.sum + end + + aliases[name] + end + + def truncate(name) + name[0..connection.table_alias_length-3] + end + + def connection + ActiveRecord::Base.connection + end + end + end +end diff --git a/activerecord/lib/active_record/associations/association.rb b/activerecord/lib/active_record/associations/association.rb index 25b4b9d90d..27c446b12c 100644 --- a/activerecord/lib/active_record/associations/association.rb +++ b/activerecord/lib/active_record/associations/association.rb @@ -93,23 +93,9 @@ module ActiveRecord # by scope.scoping { ... } or with_scope { ... } etc, which affects the scope which # actually gets built. def construct_scope - @association_scope = association_scope if klass - end - - def association_scope - scope = klass.unscoped - scope = scope.create_with(creation_attributes) - scope = scope.apply_finder_options(options.slice(:readonly, :include)) - scope = scope.where(interpolate(options[:conditions])) - if select = select_value - scope = scope.select(select) + if klass + @association_scope = AssociationScope.new(self).scope end - scope = scope.extending(*Array.wrap(options[:extend])) - scope.where(construct_owner_conditions) - end - - def aliased_table - klass.arel_table end # Set the inverse association, if possible @@ -174,42 +160,24 @@ module ActiveRecord end end - def select_value - options[:select] - end - - # Implemented by (some) subclasses def creation_attributes - { } - end - - # Returns a hash linking the owner to the association represented by the reflection - def construct_owner_attributes(reflection = reflection) attributes = {} - if reflection.macro == :belongs_to - attributes[reflection.association_primary_key] = owner[reflection.foreign_key] - else + + if [:has_one, :has_many].include?(reflection.macro) && !options[:through] attributes[reflection.foreign_key] = owner[reflection.active_record_primary_key] if reflection.options[:as] attributes[reflection.type] = owner.class.base_class.name end end - attributes - end - # Builds an array of arel nodes from the owner attributes hash - def construct_owner_conditions(table = aliased_table, reflection = reflection) - conditions = construct_owner_attributes(reflection).map do |attr, value| - table[attr].eq(value) - end - table.create_and(conditions) + attributes end # Sets the owner attributes on the given record def set_owner_attributes(record) if owner.persisted? - construct_owner_attributes.each { |key, value| record[key] = value } + creation_attributes.each { |key, value| record[key] = value } end end diff --git a/activerecord/lib/active_record/associations/association_scope.rb b/activerecord/lib/active_record/associations/association_scope.rb new file mode 100644 index 0000000000..ab102b2b8f --- /dev/null +++ b/activerecord/lib/active_record/associations/association_scope.rb @@ -0,0 +1,120 @@ +module ActiveRecord + module Associations + class AssociationScope #:nodoc: + include JoinHelper + + attr_reader :association, :alias_tracker + + delegate :klass, :owner, :reflection, :interpolate, :to => :association + delegate :chain, :conditions, :options, :source_options, :active_record, :to => :reflection + + def initialize(association) + @association = association + @alias_tracker = AliasTracker.new + end + + def scope + scope = klass.unscoped + scope = scope.extending(*Array.wrap(options[:extend])) + + # It's okay to just apply all these like this. The options will only be present if the + # association supports that option; this is enforced by the association builder. + scope = scope.apply_finder_options(options.slice( + :readonly, :include, :order, :limit, :joins, :group, :having, :offset)) + + if options[:through] && !options[:include] + scope = scope.includes(source_options[:include]) + end + + if select = select_value + scope = scope.select(select) + end + + add_constraints(scope) + end + + private + + def select_value + select_value = options[:select] + + if reflection.collection? + select_value ||= options[:uniq] && "DISTINCT #{reflection.quoted_table_name}.*" + end + + if reflection.macro == :has_and_belongs_to_many + select_value ||= reflection.klass.arel_table[Arel.star] + end + + select_value + end + + def add_constraints(scope) + tables = construct_tables + + chain.each_with_index do |reflection, i| + table, foreign_table = tables.shift, tables.first + + if reflection.source_macro == :has_and_belongs_to_many + join_table = tables.shift + + scope = scope.joins(join( + join_table, + table[reflection.active_record_primary_key]. + eq(join_table[reflection.association_foreign_key]) + )) + + table, foreign_table = join_table, tables.first + end + + if reflection.source_macro == :belongs_to + key = reflection.association_primary_key + foreign_key = reflection.foreign_key + else + key = reflection.foreign_key + foreign_key = reflection.active_record_primary_key + end + + if reflection == chain.last + scope = scope.where(table[key].eq(owner[foreign_key])) + + conditions[i].each do |condition| + if options[:through] && condition.is_a?(Hash) + condition = { table.name => condition } + end + + scope = scope.where(interpolate(condition)) + end + else + constraint = table[key].eq(foreign_table[foreign_key]) + join = join(foreign_table, constraint) + + scope = scope.joins(join) + + unless conditions[i].empty? + scope = scope.where(sanitize(conditions[i], table)) + end + end + end + + scope + end + + def alias_suffix + reflection.name + end + + def table_name_for(reflection) + if reflection == self.reflection + # If this is a polymorphic belongs_to, we want to get the klass from the + # association because it depends on the polymorphic_type attribute of + # the owner + klass.table_name + else + reflection.table_name + end + end + + end + end +end diff --git a/activerecord/lib/active_record/associations/collection_association.rb b/activerecord/lib/active_record/associations/collection_association.rb index f3761bd2c7..9f4fc44cc6 100644 --- a/activerecord/lib/active_record/associations/collection_association.rb +++ b/activerecord/lib/active_record/associations/collection_association.rb @@ -331,11 +331,6 @@ module ActiveRecord @scopes_cache[method][args] ||= scoped.readonly(nil).send(method, *args) end - 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 = [] @@ -373,14 +368,6 @@ module ActiveRecord private - def select_value - super || uniq_select_value - end - - def uniq_select_value - options[:uniq] && "DISTINCT #{reflection.quoted_table_name}.*" - end - def custom_counter_sql if options[:counter_sql] interpolate(options[:counter_sql]) diff --git a/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb b/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb index 028630977d..217213808b 100644 --- a/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb +++ b/activerecord/lib/active_record/associations/has_and_belongs_to_many_association.rb @@ -26,10 +26,6 @@ module ActiveRecord record end - def association_scope - super.joins(construct_joins) - end - private def count_records @@ -48,24 +44,6 @@ module ActiveRecord end end - def construct_joins - right = join_table - left = reflection.klass.arel_table - - condition = left[reflection.klass.primary_key].eq( - right[reflection.association_foreign_key]) - - right.create_join(right, right.create_on(condition)) - end - - def construct_owner_conditions - super(join_table) - end - - def select_value - super || reflection.klass.arel_table[Arel.star] - end - def invertible_for?(record) false end diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb index cebf3e477a..78c5c4b870 100644 --- a/activerecord/lib/active_record/associations/has_many_association.rb +++ b/activerecord/lib/active_record/associations/has_many_association.rb @@ -94,8 +94,6 @@ module ActiveRecord end end end - - alias creation_attributes construct_owner_attributes end end end diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb index acac68fda5..9d2b29685b 100644 --- a/activerecord/lib/active_record/associations/has_many_through_association.rb +++ b/activerecord/lib/active_record/associations/has_many_through_association.rb @@ -34,7 +34,9 @@ module ActiveRecord end def insert_record(record, validate = true) + ensure_not_nested return if record.new_record? && !record.save(:validate => validate) + through_record(record).save! update_counter(1) record @@ -59,6 +61,8 @@ module ActiveRecord end def build_record(attributes) + ensure_not_nested + record = super(attributes) inverse = source_reflection.inverse_of @@ -93,6 +97,8 @@ module ActiveRecord end def delete_records(records, method) + ensure_not_nested + through = owner.association(through_reflection.name) scope = through.scoped.where(construct_join_attributes(*records)) diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb index e13f97125f..1d2e8667e4 100644 --- a/activerecord/lib/active_record/associations/has_one_association.rb +++ b/activerecord/lib/active_record/associations/has_one_association.rb @@ -39,14 +39,8 @@ module ActiveRecord end end - def association_scope - super.order(options[:order]) - end - private - alias creation_attributes construct_owner_attributes - # The reason that the save param for replace is false, if for create (not just build), # is because the setting of the foreign keys is actually handled by the scoping when # the record is instantiated, and so they are set straight away and do not need to be diff --git a/activerecord/lib/active_record/associations/has_one_through_association.rb b/activerecord/lib/active_record/associations/has_one_through_association.rb index d76d729303..fdf8ae1453 100644 --- a/activerecord/lib/active_record/associations/has_one_through_association.rb +++ b/activerecord/lib/active_record/associations/has_one_through_association.rb @@ -12,6 +12,8 @@ module ActiveRecord private def create_through_record(record) + ensure_not_nested + through_proxy = owner.association(through_reflection.name) through_record = through_proxy.send(:load_target) diff --git a/activerecord/lib/active_record/associations/join_dependency.rb b/activerecord/lib/active_record/associations/join_dependency.rb index c7c3cf521c..504f25271c 100644 --- a/activerecord/lib/active_record/associations/join_dependency.rb +++ b/activerecord/lib/active_record/associations/join_dependency.rb @@ -5,18 +5,16 @@ module ActiveRecord autoload :JoinBase, 'active_record/associations/join_dependency/join_base' autoload :JoinAssociation, 'active_record/associations/join_dependency/join_association' - attr_reader :join_parts, :reflections, :table_aliases, :active_record + attr_reader :join_parts, :reflections, :alias_tracker, :active_record def initialize(base, associations, joins) - @active_record = base - @table_joins = joins - @join_parts = [JoinBase.new(base)] - @associations = {} - @reflections = [] - @table_aliases = Hash.new do |h,name| - h[name] = count_aliases_from_table_joins(name.downcase) - end - @table_aliases[base.table_name] = 1 + @active_record = base + @table_joins = joins + @join_parts = [JoinBase.new(base)] + @associations = {} + @reflections = [] + @alias_tracker = AliasTracker.new(joins) + @alias_tracker.aliased_name_for(base.table_name) # Updates the count for base.table_name to 1 build(associations) end @@ -45,20 +43,6 @@ module ActiveRecord }.flatten end - def count_aliases_from_table_joins(name) - return 0 if Arel::Table === @table_joins - - # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase - quoted_name = active_record.connection.quote_table_name(name).downcase - - @table_joins.map { |join| - # Table names + table aliases - join.left.downcase.scan( - /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/ - ).size - }.sum - end - def instantiate(rows) primary_key = join_base.aliased_primary_key parents = {} diff --git a/activerecord/lib/active_record/associations/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/join_dependency/join_association.rb index ebe39c35fe..4121a5b378 100644 --- a/activerecord/lib/active_record/associations/join_dependency/join_association.rb +++ b/activerecord/lib/active_record/associations/join_dependency/join_association.rb @@ -2,6 +2,8 @@ module ActiveRecord module Associations class JoinDependency # :nodoc: class JoinAssociation < JoinPart # :nodoc: + include JoinHelper + # The reflection of the association represented attr_reader :reflection @@ -18,10 +20,15 @@ module ActiveRecord attr_accessor :join_type # These implement abstract methods from the superclass - attr_reader :aliased_prefix, :aliased_table_name + attr_reader :aliased_prefix + + attr_reader :tables - delegate :options, :through_reflection, :source_reflection, :to => :reflection + delegate :options, :through_reflection, :source_reflection, :chain, :to => :reflection delegate :table, :table_name, :to => :parent, :prefix => :parent + delegate :alias_tracker, :to => :join_dependency + + alias :alias_suffix :parent_table_name def initialize(reflection, join_dependency, parent = nil) reflection.check_validity! @@ -37,14 +44,7 @@ module ActiveRecord @parent = parent @join_type = Arel::InnerJoin @aliased_prefix = "t#{ join_dependency.join_parts.size }" - - # This must be done eagerly upon initialisation because the alias which is produced - # depends on the state of the join dependency, but we want it to work the same way - # every time. - allocate_aliases - @table = Arel::Table.new( - table_name, :as => aliased_table_name, :engine => arel_engine - ) + @tables = construct_tables.reverse end def ==(other) @@ -60,219 +60,84 @@ module ActiveRecord end def join_to(relation) - send("join_#{reflection.macro}_to", relation) - end - - def join_relation(joining_relation) - self.join_type = Arel::OuterJoin - joining_relation.joins(self) - end - - attr_reader :table - # More semantic name given we are talking about associations - alias_method :target_table, :table - - protected - - def aliased_table_name_for(name, suffix = nil) - aliases = @join_dependency.table_aliases - - if aliases[name] != 0 # We need an alias - connection = active_record.connection - - name = connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}" - aliases[name] += 1 - name = name[0, connection.table_alias_length-3] + "_#{aliases[name]}" if aliases[name] > 1 - else - aliases[name] += 1 - end - - name - end + tables = @tables.dup + foreign_table = parent_table + + # The chain starts with the target table, but we want to end with it here (makes + # more sense in this context), so we reverse + chain.reverse.each_with_index do |reflection, i| + table = tables.shift + + case reflection.source_macro + when :belongs_to + key = reflection.association_primary_key + foreign_key = reflection.foreign_key + when :has_and_belongs_to_many + # Join the join table first... + relation.from(join( + table, + table[reflection.foreign_key]. + eq(foreign_table[reflection.active_record_primary_key]) + )) + + foreign_table, table = table, tables.shift + + key = reflection.association_primary_key + foreign_key = reflection.association_foreign_key + else + key = reflection.foreign_key + foreign_key = reflection.active_record_primary_key + end - def pluralize(table_name) - ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name - end + constraint = table[key].eq(foreign_table[foreign_key]) - private + if reflection.klass.finder_needs_type_condition? + constraint = table.create_and([ + constraint, + reflection.klass.send(:type_condition, table) + ]) + end - def allocate_aliases - @aliased_table_name = aliased_table_name_for(table_name) + relation.from(join(table, constraint)) - if reflection.macro == :has_and_belongs_to_many - @aliased_join_table_name = aliased_table_name_for(reflection.options[:join_table], "_join") - elsif [:has_many, :has_one].include?(reflection.macro) && reflection.options[:through] - @aliased_join_table_name = aliased_table_name_for(reflection.through_reflection.klass.table_name, "_join") - end - end + unless conditions[i].empty? + relation.where(sanitize(conditions[i], table)) + end - def process_conditions(conditions, table_name) - if conditions.respond_to?(:to_proc) - conditions = instance_eval(&conditions) + # The current table in this iteration becomes the foreign table in the next + foreign_table = table end - Arel.sql(sanitize_sql(conditions, table_name)) + relation end - def sanitize_sql(condition, table_name) - active_record.send(:sanitize_sql, condition, table_name) + def join_relation(joining_relation) + self.join_type = Arel::OuterJoin + joining_relation.joins(self) end - def join_target_table(relation, condition) - conditions = [condition] - - # If the target table is an STI model then we must be sure to only include records of - # its type and its sub-types. - unless active_record.descends_from_active_record? - sti_column = target_table[active_record.inheritance_column] - subclasses = active_record.descendants - sti_condition = sti_column.eq(active_record.sti_name) - - conditions << subclasses.inject(sti_condition) { |attr,subclass| - attr.or(sti_column.eq(subclass.sti_name)) - } - end - - # If the reflection has conditions, add them - if options[:conditions] - conditions << process_conditions(options[:conditions], aliased_table_name) - end - - ands = relation.create_and(conditions) - - join = relation.create_join( - target_table, - relation.create_on(ands), - join_type) - - relation.from join + def table + tables.last end - def join_has_and_belongs_to_many_to(relation) - join_table = Arel::Table.new( - options[:join_table] - ).alias(@aliased_join_table_name) - - fk = options[:foreign_key] || reflection.active_record.to_s.foreign_key - klass_fk = options[:association_foreign_key] || reflection.klass.to_s.foreign_key - - relation = relation.join(join_table, join_type) - relation = relation.on( - join_table[fk]. - eq(parent_table[reflection.active_record.primary_key]) - ) - - join_target_table( - relation, - target_table[reflection.klass.primary_key]. - eq(join_table[klass_fk]) - ) + def aliased_table_name + table.table_alias || table.name end - def join_has_many_to(relation) - if reflection.options[:through] - join_has_many_through_to(relation) - elsif reflection.options[:as] - join_has_many_polymorphic_to(relation) - else - foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key - primary_key = options[:primary_key] || parent.primary_key - - join_target_table( - relation, - target_table[foreign_key]. - eq(parent_table[primary_key]) - ) - end + def conditions + @conditions ||= reflection.conditions.reverse end - alias :join_has_one_to :join_has_many_to - - def join_has_many_through_to(relation) - join_table = Arel::Table.new( - through_reflection.klass.table_name - ).alias @aliased_join_table_name - jt_conditions = [] - first_key = second_key = nil + private - if through_reflection.macro == :belongs_to - jt_primary_key = through_reflection.foreign_key - jt_foreign_key = through_reflection.association_primary_key + def interpolate(conditions) + if conditions.respond_to?(:to_proc) + instance_eval(&conditions) else - jt_primary_key = through_reflection.active_record_primary_key - jt_foreign_key = through_reflection.foreign_key - - if through_reflection.options[:as] # has_many :through against a polymorphic join - jt_conditions << - join_table["#{through_reflection.options[:as]}_type"]. - eq(parent.active_record.base_class.name) - end + conditions end - - case source_reflection.macro - when :has_many - second_key = options[:foreign_key] || primary_key - - if source_reflection.options[:as] - first_key = "#{source_reflection.options[:as]}_id" - else - first_key = through_reflection.klass.base_class.to_s.foreign_key - end - - unless through_reflection.klass.descends_from_active_record? - jt_conditions << - join_table[through_reflection.active_record.inheritance_column]. - eq(through_reflection.klass.sti_name) - end - when :belongs_to - first_key = primary_key - - if reflection.options[:source_type] - second_key = source_reflection.association_foreign_key - - jt_conditions << - join_table[reflection.source_reflection.foreign_type]. - eq(reflection.options[:source_type]) - else - second_key = source_reflection.foreign_key - end - end - - jt_conditions << - parent_table[jt_primary_key]. - eq(join_table[jt_foreign_key]) - - if through_reflection.options[:conditions] - jt_conditions << process_conditions(through_reflection.options[:conditions], aliased_table_name) - end - - relation = relation.join(join_table, join_type).on(*jt_conditions) - - join_target_table( - relation, - target_table[first_key].eq(join_table[second_key]) - ) end - def join_has_many_polymorphic_to(relation) - join_target_table( - relation, - target_table["#{reflection.options[:as]}_id"]. - eq(parent_table[parent.primary_key]).and( - target_table["#{reflection.options[:as]}_type"]. - eq(parent.active_record.base_class.name)) - ) - end - - def join_belongs_to_to(relation) - foreign_key = options[:foreign_key] || reflection.foreign_key - primary_key = options[:primary_key] || reflection.klass.primary_key - - join_target_table( - relation, - target_table[primary_key].eq(parent_table[foreign_key]) - ) - end end end end diff --git a/activerecord/lib/active_record/associations/join_helper.rb b/activerecord/lib/active_record/associations/join_helper.rb new file mode 100644 index 0000000000..eae546e76e --- /dev/null +++ b/activerecord/lib/active_record/associations/join_helper.rb @@ -0,0 +1,56 @@ +module ActiveRecord + module Associations + # Helper class module which gets mixed into JoinDependency::JoinAssociation and AssociationScope + module JoinHelper #:nodoc: + + def join_type + Arel::InnerJoin + end + + private + + def construct_tables + tables = [] + chain.each do |reflection| + tables << alias_tracker.aliased_table_for( + table_name_for(reflection), + table_alias_for(reflection, reflection != self.reflection) + ) + + if reflection.source_macro == :has_and_belongs_to_many + tables << alias_tracker.aliased_table_for( + (reflection.source_reflection || reflection).options[:join_table], + table_alias_for(reflection, true) + ) + end + end + tables + end + + def table_name_for(reflection) + reflection.table_name + end + + def table_alias_for(reflection, join = false) + name = alias_tracker.pluralize(reflection.name) + name << "_#{alias_suffix}" + name << "_join" if join + name + end + + def join(table, constraint) + table.create_join(table, table.create_on(constraint), join_type) + end + + def sanitize(conditions, table) + conditions = conditions.map do |condition| + condition = active_record.send(:sanitize_sql, interpolate(condition), table.table_alias || table.name) + condition = Arel.sql(condition) unless condition.is_a?(Arel::Node) + condition + end + + conditions.length == 1 ? conditions.first : Arel::Nodes::And.new(conditions) + end + end + end +end diff --git a/activerecord/lib/active_record/associations/preloader/through_association.rb b/activerecord/lib/active_record/associations/preloader/through_association.rb index d630fc4c63..ad6374d09a 100644 --- a/activerecord/lib/active_record/associations/preloader/through_association.rb +++ b/activerecord/lib/active_record/associations/preloader/through_association.rb @@ -19,8 +19,9 @@ module ActiveRecord source_reflection.name, options ).run - through_records.each do |owner, owner_through_records| - owner_through_records.map! { |r| r.send(source_reflection.name) }.flatten! + through_records.each do |owner, records| + records.map! { |r| r.send(source_reflection.name) }.flatten! + records.compact! end end diff --git a/activerecord/lib/active_record/associations/through_association.rb b/activerecord/lib/active_record/associations/through_association.rb index e1d60ccb17..e6ab628719 100644 --- a/activerecord/lib/active_record/associations/through_association.rb +++ b/activerecord/lib/active_record/associations/through_association.rb @@ -3,79 +3,24 @@ module ActiveRecord module Associations module ThroughAssociation #:nodoc: - delegate :source_options, :through_options, :source_reflection, :through_reflection, :to => :reflection + delegate :source_reflection, :through_reflection, :chain, :to => :reflection protected + # We merge in these scopes for two reasons: + # + # 1. To get the default_scope conditions for any of the other reflections in the chain + # 2. To get the type conditions for any STI models in the chain def target_scope - super.merge(through_reflection.klass.scoped) - end - - def association_scope - scope = super.joins(construct_joins) - scope = add_conditions(scope) - unless options[:include] - scope = scope.includes(source_options[:include]) + scope = super + chain[1..-1].each do |reflection| + scope = scope.merge(reflection.klass.scoped) end scope end private - # This scope affects the creation of the associated records (not the join records). At the - # moment we only support creating on a :through association when the source reflection is a - # belongs_to. Thus it's not necessary to set a foreign key on the associated record(s), so - # this scope has can legitimately be empty. - def creation_attributes - { } - end - - def aliased_through_table - name = through_reflection.table_name - - reflection.table_name == name ? - through_reflection.klass.arel_table.alias(name + "_join") : - through_reflection.klass.arel_table - end - - def construct_owner_conditions - super(aliased_through_table, through_reflection) - end - - def construct_joins - right = aliased_through_table - left = reflection.klass.arel_table - - conditions = [] - - if source_reflection.macro == :belongs_to - reflection_primary_key = source_reflection.association_primary_key - source_primary_key = source_reflection.foreign_key - - if options[:source_type] - column = source_reflection.foreign_type - conditions << - right[column].eq(options[:source_type]) - end - else - reflection_primary_key = source_reflection.foreign_key - source_primary_key = source_reflection.active_record_primary_key - - if source_options[:as] - column = "#{source_options[:as]}_type" - conditions << - left[column].eq(through_reflection.klass.name) - end - end - - conditions << - left[reflection_primary_key].eq(right[source_primary_key]) - - right.create_join( - right, - right.create_on(right.create_and(conditions))) - end - # Construct attributes for :through pointing to owner and associate. This is used by the # methods which create and delete records on the association. # @@ -112,37 +57,8 @@ module ActiveRecord end end - # The reason that we are operating directly on the scope here (rather than passing - # back some arel conditions to be added to the scope) is because scope.where([x, y]) - # has a different meaning to scope.where(x).where(y) - the first version might - # perform some substitution if x is a string. - def add_conditions(scope) - unless through_reflection.klass.descends_from_active_record? - scope = scope.where(through_reflection.klass.send(:type_condition)) - end - - scope = scope.where(interpolate(source_options[:conditions])) - scope.where(through_conditions) - end - - # If there is a hash of conditions then we make sure the keys are scoped to the - # through table name if left ambiguous. - def through_conditions - conditions = interpolate(through_options[:conditions]) - - if conditions.is_a?(Hash) - Hash[conditions.map { |key, value| - unless value.is_a?(Hash) || key.to_s.include?('.') - key = aliased_through_table.name + '.' + key.to_s - end - - [key, value] - }] - else - conditions - end - end - + # Note: this does not capture all cases, for example it would be crazy to try to + # properly support stale-checking for nested associations. def stale_state if through_reflection.macro == :belongs_to owner[through_reflection.foreign_key].to_s @@ -153,6 +69,12 @@ module ActiveRecord through_reflection.macro == :belongs_to && !owner[through_reflection.foreign_key].nil? end + + def ensure_not_nested + if reflection.nested? + raise HasManyThroughNestedAssociationsAreReadonly.new(owner, reflection) + end + end end end end diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb index a5e1c91f47..7f506faeee 100644 --- a/activerecord/lib/active_record/base.rb +++ b/activerecord/lib/active_record/base.rb @@ -973,8 +973,8 @@ module ActiveRecord #:nodoc: relation end - def type_condition - sti_column = arel_table[inheritance_column.to_sym] + def type_condition(table = arel_table) + sti_column = table[inheritance_column.to_sym] sti_names = ([self] + descendants).map { |model| model.sti_name } sti_column.in(sti_names) diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb index 5de08953f9..e801bc4afa 100644 --- a/activerecord/lib/active_record/reflection.rb +++ b/activerecord/lib/active_record/reflection.rb @@ -262,16 +262,30 @@ module ActiveRecord end def through_reflection - false - end - - def through_reflection_foreign_key + nil end def source_reflection nil end + # A chain of reflections from this one back to the owner. For more see the explanation in + # ThroughReflection. + def chain + [self] + end + + # An array of arrays of conditions. Each item in the outside array corresponds to a reflection + # in the #chain. The inside arrays are simply conditions (and each condition may itself be + # a hash, array, arel predicate, etc...) + def conditions + conditions = [options[:conditions]].compact + conditions << { type => active_record.base_class.name } if options[:as] + [conditions] + end + + alias :source_macro :macro + def has_inverse? @options[:inverse_of] end @@ -363,7 +377,7 @@ module ActiveRecord # Holds all the meta-data about a :through association as it was specified # in the Active Record class. class ThroughReflection < AssociationReflection #:nodoc: - delegate :association_primary_key, :foreign_type, :to => :source_reflection + delegate :foreign_key, :foreign_type, :association_foreign_key, :active_record_primary_key, :to => :source_reflection # Gets the source of the through reflection. It checks both a singularized # and pluralized form for <tt>:belongs_to</tt> or <tt>:has_many</tt>. @@ -392,6 +406,88 @@ module ActiveRecord @through_reflection ||= active_record.reflect_on_association(options[:through]) end + # Returns an array of reflections which are involved in this association. Each item in the + # array corresponds to a table which will be part of the query for this association. + # + # The chain is built by recursively calling #chain on the source reflection and the through + # reflection. The base case for the recursion is a normal association, which just returns + # [self] as its #chain. + def chain + @chain ||= begin + chain = source_reflection.chain + through_reflection.chain + chain[0] = self # Use self so we don't lose the information from :source_type + chain + end + end + + # Consider the following example: + # + # class Person + # has_many :articles + # has_many :comment_tags, :through => :articles + # end + # + # class Article + # has_many :comments + # has_many :comment_tags, :through => :comments, :source => :tags + # end + # + # class Comment + # has_many :tags + # end + # + # There may be conditions on Person.comment_tags, Article.comment_tags and/or Comment.tags, + # but only Comment.tags will be represented in the #chain. So this method creates an array + # of conditions corresponding to the chain. Each item in the #conditions array corresponds + # to an item in the #chain, and is itself an array of conditions from an arbitrary number + # of relevant reflections, plus any :source_type or polymorphic :as constraints. + def conditions + @conditions ||= begin + conditions = source_reflection.conditions + + # Add to it the conditions from this reflection if necessary. + conditions.first << options[:conditions] if options[:conditions] + + through_conditions = through_reflection.conditions + + if options[:source_type] + through_conditions.first << { foreign_type => options[:source_type] } + end + + # Recursively fill out the rest of the array from the through reflection + conditions += through_conditions + + # And return + conditions + end + end + + # The macro used by the source association + def source_macro + source_reflection.source_macro + end + + # A through association is nested iff there would be more than one join table + def nested? + chain.length > 2 || through_reflection.macro == :has_and_belongs_to_many + end + + # We want to use the klass from this reflection, rather than just delegate straight to + # the source_reflection, because the source_reflection may be polymorphic. We still + # need to respect the source_reflection's :primary_key option, though. + def association_primary_key + @association_primary_key ||= begin + # Get the "actual" source reflection if the immediate source reflection has a + # source reflection itself + source_reflection = self.source_reflection + while source_reflection.source_reflection + source_reflection = source_reflection.source_reflection + end + + source_reflection.options[:primary_key] || klass.primary_key + end + end + # Gets an array of possible <tt>:through</tt> source reflection names: # # [:singularized, :pluralized] @@ -429,10 +525,6 @@ module ActiveRecord raise HasManyThroughAssociationPolymorphicSourceError.new(active_record.name, self, source_reflection) end - unless [:belongs_to, :has_many, :has_one].include?(source_reflection.macro) && source_reflection.options[:through].nil? - raise HasManyThroughSourceAssociationMacroError.new(self) - end - if macro == :has_one && through_reflection.collection? raise HasOneThroughCantAssociateThroughCollection.new(active_record.name, self, through_reflection) end @@ -440,14 +532,6 @@ module ActiveRecord check_validity_of_inverse! end - def through_reflection_primary_key - through_reflection.belongs_to? ? through_reflection.klass.primary_key : through_reflection.foreign_key - end - - def through_reflection_foreign_key - through_reflection.foreign_key if through_reflection.belongs_to? - end - private def derive_class_name # get the class_name of the belongs_to association of the through reflection diff --git a/activerecord/lib/active_record/relation/query_methods.rb b/activerecord/lib/active_record/relation/query_methods.rb index cd1d7108b3..9470e7c6c5 100644 --- a/activerecord/lib/active_record/relation/query_methods.rb +++ b/activerecord/lib/active_record/relation/query_methods.rb @@ -261,7 +261,7 @@ module ActiveRecord ) join_nodes.each do |join| - join_dependency.table_aliases[join.left.name.downcase] = 1 + join_dependency.alias_tracker.aliased_name_for(join.left.name.downcase) end join_dependency.graft(*stashed_association_joins) |