diff options
Diffstat (limited to 'activerecord/lib/active_record')
5 files changed, 605 insertions, 574 deletions
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb index 7da38cd03f..0d9171d876 100644 --- a/activerecord/lib/active_record/associations.rb +++ b/activerecord/lib/active_record/associations.rb @@ -5,6 +5,7 @@ require 'active_support/core_ext/object/blank' require 'active_support/core_ext/string/conversions' require 'active_support/core_ext/module/remove_method' require 'active_support/core_ext/class/attribute' +require 'active_record/associations/class_methods/join_dependency' module ActiveRecord class InverseOfAssociationNotFoundError < ActiveRecordError #:nodoc: @@ -1832,580 +1833,6 @@ module ActiveRecord Array.wrap(extensions) end end - - class JoinDependency # :nodoc: - attr_reader :join_parts, :reflections, :table_aliases - - def initialize(base, associations, joins) - @join_parts = [JoinBase.new(base, joins)] - @associations = {} - @reflections = [] - @table_aliases = Hash.new(0) - @table_aliases[base.table_name] = 1 - build(associations) - end - - def graft(*associations) - associations.each do |association| - join_associations.detect {|a| association == a} || - build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type) - end - self - end - - def join_associations - join_parts.last(join_parts.length - 1) - end - - def join_base - join_parts.first - end - - def count_aliases_from_table_joins(name) - # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase - quoted_name = join_base.active_record.connection.quote_table_name(name.downcase).downcase - join_sql = join_base.table_joins.to_s.downcase - join_sql.blank? ? 0 : - # Table names - join_sql.scan(/join(?:\s+\w+)?\s+#{quoted_name}\son/).size + - # Table aliases - join_sql.scan(/join(?:\s+\w+)?\s+\S+\s+#{quoted_name}\son/).size - end - - def instantiate(rows) - primary_key = join_base.aliased_primary_key - parents = {} - - records = rows.map { |model| - primary_id = model[primary_key] - parent = parents[primary_id] ||= join_base.instantiate(model) - construct(parent, @associations, join_associations.dup, model) - parent - }.uniq - - remove_duplicate_results!(join_base.active_record, records, @associations) - records - end - - def remove_duplicate_results!(base, records, associations) - case associations - when Symbol, String - reflection = base.reflections[associations] - remove_uniq_by_reflection(reflection, records) - when Array - associations.each do |association| - remove_duplicate_results!(base, records, association) - end - when Hash - associations.keys.each do |name| - reflection = base.reflections[name] - remove_uniq_by_reflection(reflection, records) - - parent_records = [] - records.each do |record| - if descendant = record.send(reflection.name) - if reflection.collection? - parent_records.concat descendant.target.uniq - else - parent_records << descendant - end - end - end - - remove_duplicate_results!(reflection.klass, parent_records, associations[name]) unless parent_records.empty? - end - end - end - - protected - - def cache_joined_association(association) - associations = [] - parent = association.parent - while parent != join_base - associations.unshift(parent.reflection.name) - parent = parent.parent - end - ref = @associations - associations.each do |key| - ref = ref[key] - end - ref[association.reflection.name] ||= {} - end - - def build(associations, parent = nil, join_type = Arel::InnerJoin) - parent ||= join_parts.last - case associations - when Symbol, String - reflection = parent.reflections[associations.to_s.intern] or - raise ConfigurationError, "Association named '#{ associations }' was not found; perhaps you misspelled it?" - unless join_association = find_join_association(reflection, parent) - @reflections << reflection - join_association = build_join_association(reflection, parent) - join_association.join_type = join_type - @join_parts << join_association - cache_joined_association(join_association) - end - join_association - when Array - associations.each do |association| - build(association, parent, join_type) - end - when Hash - associations.keys.sort{|a,b|a.to_s<=>b.to_s}.each do |name| - join_association = build(name, parent, join_type) - build(associations[name], join_association, join_type) - end - else - raise ConfigurationError, associations.inspect - end - end - - def find_join_association(name_or_reflection, parent) - if String === name_or_reflection - name_or_reflection = name_or_reflection.to_sym - end - - join_associations.detect { |j| - j.reflection == name_or_reflection && j.parent == parent - } - end - - def remove_uniq_by_reflection(reflection, records) - if reflection && reflection.collection? - records.each { |record| record.send(reflection.name).target.uniq! } - end - end - - def build_join_association(reflection, parent) - JoinAssociation.new(reflection, self, parent) - end - - def construct(parent, associations, join_parts, row) - case associations - when Symbol, String - name = associations.to_s - - join_part = join_parts.detect { |j| - j.reflection.name.to_s == name && - j.parent_table_name == parent.class.table_name } - - raise(ConfigurationError, "No such association") unless join_part - - join_parts.delete(join_part) - construct_association(parent, join_part, row) - when Array - associations.each do |association| - construct(parent, association, join_parts, row) - end - when Hash - associations.sort_by { |k,_| k.to_s }.each do |name, assoc| - association = construct(parent, name, join_parts, row) - construct(association, assoc, join_parts, row) if association - end - else - raise ConfigurationError, associations.inspect - end - end - - def construct_association(record, join_part, row) - return if record.id.to_s != join_part.parent.record_id(row).to_s - - macro = join_part.reflection.macro - if macro == :has_one - return if record.instance_variable_defined?("@#{join_part.reflection.name}") - association = join_part.instantiate(row) unless row[join_part.aliased_primary_key].nil? - set_target_and_inverse(join_part, association, record) - else - return if row[join_part.aliased_primary_key].nil? - association = join_part.instantiate(row) - case macro - when :has_many, :has_and_belongs_to_many - collection = record.send(join_part.reflection.name) - collection.loaded - collection.target.push(association) - collection.__send__(:set_inverse_instance, association, record) - when :belongs_to - set_target_and_inverse(join_part, association, record) - else - raise ConfigurationError, "unknown macro: #{join_part.reflection.macro}" - end - end - association - end - - def set_target_and_inverse(join_part, association, record) - association_proxy = record.send("set_#{join_part.reflection.name}_target", association) - association_proxy.__send__(:set_inverse_instance, association, record) - end - - # A JoinPart represents a part of a JoinDependency. It is an abstract class, inherited - # by JoinBase and JoinAssociation. A JoinBase represents the Active Record which - # everything else is being joined onto. A JoinAssociation represents an association which - # is joining to the base. A JoinAssociation may result in more than one actual join - # operations (for example a has_and_belongs_to_many JoinAssociation would result in - # two; one for the join table and one for the target table). - class JoinPart # :nodoc: - # The Active Record class which this join part is associated 'about'; for a JoinBase - # this is the actual base model, for a JoinAssociation this is the target model of the - # association. - attr_reader :active_record - - delegate :table_name, :column_names, :primary_key, :reflections, :sanitize_sql, :arel_engine, :to => :active_record - - def initialize(active_record) - @active_record = active_record - @cached_record = {} - end - - def ==(other) - raise NotImplementedError - end - - # An Arel::Table for the active_record - def table - raise NotImplementedError - end - - # The prefix to be used when aliasing columns in the active_record's table - def aliased_prefix - raise NotImplementedError - end - - # The alias for the active_record's table - def aliased_table_name - raise NotImplementedError - end - - # The alias for the primary key of the active_record's table - def aliased_primary_key - "#{aliased_prefix}_r0" - end - - # An array of [column_name, alias] pairs for the table - def column_names_with_alias - unless defined?(@column_names_with_alias) - @column_names_with_alias = [] - - ([primary_key] + (column_names - [primary_key])).each_with_index do |column_name, i| - @column_names_with_alias << [column_name, "#{aliased_prefix}_r#{i}"] - end - end - - @column_names_with_alias - end - - def extract_record(row) - Hash[column_names_with_alias.map{|cn, an| [cn, row[an]]}] - end - - def record_id(row) - row[aliased_primary_key] - end - - def instantiate(row) - @cached_record[record_id(row)] ||= active_record.send(:instantiate, extract_record(row)) - end - end - - class JoinBase < JoinPart # :nodoc: - # Extra joins provided when the JoinDependency was created - attr_reader :table_joins - - def initialize(active_record, joins = nil) - super(active_record) - @table_joins = joins - end - - def ==(other) - other.class == self.class && - other.active_record == active_record - end - - def aliased_prefix - "t0" - end - - def table - Arel::Table.new(table_name, :engine => arel_engine, :columns => active_record.columns) - end - - def aliased_table_name - active_record.table_name - end - end - - class JoinAssociation < JoinPart # :nodoc: - # The reflection of the association represented - attr_reader :reflection - - # The JoinDependency object which this JoinAssociation exists within. This is mainly - # relevant for generating aliases which do not conflict with other joins which are - # part of the query. - attr_reader :join_dependency - - # A JoinBase instance representing the active record we are joining onto. - # (So in Author.has_many :posts, the Author would be that base record.) - attr_reader :parent - - # What type of join will be generated, either Arel::InnerJoin (default) or Arel::OuterJoin - attr_accessor :join_type - - # These implement abstract methods from the superclass - attr_reader :aliased_prefix, :aliased_table_name - - delegate :options, :through_reflection, :source_reflection, :to => :reflection - delegate :table, :table_name, :to => :parent, :prefix => true - - def initialize(reflection, join_dependency, parent = nil) - reflection.check_validity! - - if reflection.options[:polymorphic] - raise EagerLoadPolymorphicError.new(reflection) - end - - super(reflection.klass) - - @reflection = reflection - @join_dependency = join_dependency - @parent = parent - @join_type = Arel::InnerJoin - - # 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 - end - - def ==(other) - other.class == self.class && - other.reflection == reflection && - other.parent == parent - end - - def find_parent_in(other_join_dependency) - other_join_dependency.join_parts.detect do |join_part| - self.parent == join_part - end - 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 - - def table - @table ||= Arel::Table.new( - table_name, :as => aliased_table_name, - :engine => arel_engine, :columns => active_record.columns - ) - end - - # More semantic name given we are talking about associations - alias_method :target_table, :table - - protected - - def aliased_table_name_for(name, suffix = nil) - if @join_dependency.table_aliases[name].zero? - @join_dependency.table_aliases[name] = @join_dependency.count_aliases_from_table_joins(name) - end - - if !@join_dependency.table_aliases[name].zero? # We need an alias - name = active_record.connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}" - @join_dependency.table_aliases[name] += 1 - if @join_dependency.table_aliases[name] == 1 # First time we've seen this name - # Also need to count the aliases from the table_aliases to avoid incorrect count - @join_dependency.table_aliases[name] += @join_dependency.count_aliases_from_table_joins(name) - end - table_index = @join_dependency.table_aliases[name] - name = name[0..active_record.connection.table_alias_length-3] + "_#{table_index}" if table_index > 1 - else - @join_dependency.table_aliases[name] += 1 - end - - name - end - - def pluralize(table_name) - ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name - end - - def interpolate_sql(sql) - instance_eval("%@#{sql.gsub('@', '\@')}@", __FILE__, __LINE__) - end - - private - - def allocate_aliases - @aliased_prefix = "t#{ join_dependency.join_parts.size }" - @aliased_table_name = aliased_table_name_for(table_name) - - 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 - - def process_conditions(conditions, table_name) - Arel.sql(interpolate_sql(sanitize_sql(conditions, table_name))) - end - - def join_target_table(relation, *conditions) - relation = relation.join(target_table, join_type) - - # 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] - - sti_condition = sti_column.eq(active_record.sti_name) - active_record.descendants.each do |subclass| - sti_condition = sti_condition.or(sti_column.eq(subclass.sti_name)) - end - - conditions << sti_condition - end - - # If the reflection has conditions, add them - if options[:conditions] - conditions << process_conditions(options[:conditions], aliased_table_name) - end - - relation = relation.on(*conditions) - end - - def join_has_and_belongs_to_many_to(relation) - join_table = Arel::Table.new( - options[:join_table], :engine => arel_engine, - :as => @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]) - ) - 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 - 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, :engine => arel_engine, - :as => @aliased_join_table_name - ) - - jt_conditions = [] - jt_foreign_key = first_key = second_key = nil - - if through_reflection.options[:as] # has_many :through against a polymorphic join - as_key = through_reflection.options[:as].to_s - jt_foreign_key = as_key + '_id' - - jt_conditions << - join_table[as_key + '_type']. - eq(parent.active_record.base_class.name) - else - jt_foreign_key = through_reflection.primary_key_name - 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.options[:foreign_type]]. - eq(reflection.options[:source_type]) - else - second_key = source_reflection.primary_key_name - end - end - - jt_conditions << - parent_table[parent.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]), - 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.primary_key_name - 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 end end diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency.rb new file mode 100644 index 0000000000..79fdb2d4cb --- /dev/null +++ b/activerecord/lib/active_record/associations/class_methods/join_dependency.rb @@ -0,0 +1,216 @@ +require 'active_record/associations/class_methods/join_dependency/join_part' +require 'active_record/associations/class_methods/join_dependency/join_base' +require 'active_record/associations/class_methods/join_dependency/join_association' + +module ActiveRecord + module Associations + module ClassMethods + class JoinDependency # :nodoc: + attr_reader :join_parts, :reflections, :table_aliases + + def initialize(base, associations, joins) + @join_parts = [JoinBase.new(base, joins)] + @associations = {} + @reflections = [] + @table_aliases = Hash.new(0) + @table_aliases[base.table_name] = 1 + build(associations) + end + + def graft(*associations) + associations.each do |association| + join_associations.detect {|a| association == a} || + build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type) + end + self + end + + def join_associations + join_parts.last(join_parts.length - 1) + end + + def join_base + join_parts.first + end + + def count_aliases_from_table_joins(name) + # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase + quoted_name = join_base.active_record.connection.quote_table_name(name.downcase).downcase + join_sql = join_base.table_joins.to_s.downcase + join_sql.blank? ? 0 : + # Table names + join_sql.scan(/join(?:\s+\w+)?\s+#{quoted_name}\son/).size + + # Table aliases + join_sql.scan(/join(?:\s+\w+)?\s+\S+\s+#{quoted_name}\son/).size + end + + def instantiate(rows) + primary_key = join_base.aliased_primary_key + parents = {} + + records = rows.map { |model| + primary_id = model[primary_key] + parent = parents[primary_id] ||= join_base.instantiate(model) + construct(parent, @associations, join_associations.dup, model) + parent + }.uniq + + remove_duplicate_results!(join_base.active_record, records, @associations) + records + end + + def remove_duplicate_results!(base, records, associations) + case associations + when Symbol, String + reflection = base.reflections[associations] + remove_uniq_by_reflection(reflection, records) + when Array + associations.each do |association| + remove_duplicate_results!(base, records, association) + end + when Hash + associations.keys.each do |name| + reflection = base.reflections[name] + remove_uniq_by_reflection(reflection, records) + + parent_records = [] + records.each do |record| + if descendant = record.send(reflection.name) + if reflection.collection? + parent_records.concat descendant.target.uniq + else + parent_records << descendant + end + end + end + + remove_duplicate_results!(reflection.klass, parent_records, associations[name]) unless parent_records.empty? + end + end + end + + protected + + def cache_joined_association(association) + associations = [] + parent = association.parent + while parent != join_base + associations.unshift(parent.reflection.name) + parent = parent.parent + end + ref = @associations + associations.each do |key| + ref = ref[key] + end + ref[association.reflection.name] ||= {} + end + + def build(associations, parent = nil, join_type = Arel::InnerJoin) + parent ||= join_parts.last + case associations + when Symbol, String + reflection = parent.reflections[associations.to_s.intern] or + raise ConfigurationError, "Association named '#{ associations }' was not found; perhaps you misspelled it?" + unless join_association = find_join_association(reflection, parent) + @reflections << reflection + join_association = build_join_association(reflection, parent) + join_association.join_type = join_type + @join_parts << join_association + cache_joined_association(join_association) + end + join_association + when Array + associations.each do |association| + build(association, parent, join_type) + end + when Hash + associations.keys.sort{|a,b|a.to_s<=>b.to_s}.each do |name| + join_association = build(name, parent, join_type) + build(associations[name], join_association, join_type) + end + else + raise ConfigurationError, associations.inspect + end + end + + def find_join_association(name_or_reflection, parent) + if String === name_or_reflection + name_or_reflection = name_or_reflection.to_sym + end + + join_associations.detect { |j| + j.reflection == name_or_reflection && j.parent == parent + } + end + + def remove_uniq_by_reflection(reflection, records) + if reflection && reflection.collection? + records.each { |record| record.send(reflection.name).target.uniq! } + end + end + + def build_join_association(reflection, parent) + JoinAssociation.new(reflection, self, parent) + end + + def construct(parent, associations, join_parts, row) + case associations + when Symbol, String + name = associations.to_s + + join_part = join_parts.detect { |j| + j.reflection.name.to_s == name && + j.parent_table_name == parent.class.table_name } + + raise(ConfigurationError, "No such association") unless join_part + + join_parts.delete(join_part) + construct_association(parent, join_part, row) + when Array + associations.each do |association| + construct(parent, association, join_parts, row) + end + when Hash + associations.sort_by { |k,_| k.to_s }.each do |name, assoc| + association = construct(parent, name, join_parts, row) + construct(association, assoc, join_parts, row) if association + end + else + raise ConfigurationError, associations.inspect + end + end + + def construct_association(record, join_part, row) + return if record.id.to_s != join_part.parent.record_id(row).to_s + + macro = join_part.reflection.macro + if macro == :has_one + return if record.instance_variable_defined?("@#{join_part.reflection.name}") + association = join_part.instantiate(row) unless row[join_part.aliased_primary_key].nil? + set_target_and_inverse(join_part, association, record) + else + return if row[join_part.aliased_primary_key].nil? + association = join_part.instantiate(row) + case macro + when :has_many, :has_and_belongs_to_many + collection = record.send(join_part.reflection.name) + collection.loaded + collection.target.push(association) + collection.__send__(:set_inverse_instance, association, record) + when :belongs_to + set_target_and_inverse(join_part, association, record) + else + raise ConfigurationError, "unknown macro: #{join_part.reflection.macro}" + end + end + association + end + + def set_target_and_inverse(join_part, association, record) + association_proxy = record.send("set_#{join_part.reflection.name}_target", association) + association_proxy.__send__(:set_inverse_instance, association, record) + end + end + end + end +end diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb new file mode 100644 index 0000000000..5e5c01c77a --- /dev/null +++ b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_association.rb @@ -0,0 +1,278 @@ +module ActiveRecord + module Associations + module ClassMethods + class JoinDependency # :nodoc: + class JoinAssociation < JoinPart # :nodoc: + # The reflection of the association represented + attr_reader :reflection + + # The JoinDependency object which this JoinAssociation exists within. This is mainly + # relevant for generating aliases which do not conflict with other joins which are + # part of the query. + attr_reader :join_dependency + + # A JoinBase instance representing the active record we are joining onto. + # (So in Author.has_many :posts, the Author would be that base record.) + attr_reader :parent + + # What type of join will be generated, either Arel::InnerJoin (default) or Arel::OuterJoin + attr_accessor :join_type + + # These implement abstract methods from the superclass + attr_reader :aliased_prefix, :aliased_table_name + + delegate :options, :through_reflection, :source_reflection, :to => :reflection + delegate :table, :table_name, :to => :parent, :prefix => true + + def initialize(reflection, join_dependency, parent = nil) + reflection.check_validity! + + if reflection.options[:polymorphic] + raise EagerLoadPolymorphicError.new(reflection) + end + + super(reflection.klass) + + @reflection = reflection + @join_dependency = join_dependency + @parent = parent + @join_type = Arel::InnerJoin + + # 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 + end + + def ==(other) + other.class == self.class && + other.reflection == reflection && + other.parent == parent + end + + def find_parent_in(other_join_dependency) + other_join_dependency.join_parts.detect do |join_part| + self.parent == join_part + end + 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 + + def table + @table ||= Arel::Table.new( + table_name, :as => aliased_table_name, + :engine => arel_engine, :columns => active_record.columns + ) + end + + # More semantic name given we are talking about associations + alias_method :target_table, :table + + protected + + def aliased_table_name_for(name, suffix = nil) + if @join_dependency.table_aliases[name].zero? + @join_dependency.table_aliases[name] = @join_dependency.count_aliases_from_table_joins(name) + end + + if !@join_dependency.table_aliases[name].zero? # We need an alias + name = active_record.connection.table_alias_for "#{pluralize(reflection.name)}_#{parent_table_name}#{suffix}" + @join_dependency.table_aliases[name] += 1 + if @join_dependency.table_aliases[name] == 1 # First time we've seen this name + # Also need to count the aliases from the table_aliases to avoid incorrect count + @join_dependency.table_aliases[name] += @join_dependency.count_aliases_from_table_joins(name) + end + table_index = @join_dependency.table_aliases[name] + name = name[0..active_record.connection.table_alias_length-3] + "_#{table_index}" if table_index > 1 + else + @join_dependency.table_aliases[name] += 1 + end + + name + end + + def pluralize(table_name) + ActiveRecord::Base.pluralize_table_names ? table_name.to_s.pluralize : table_name + end + + def interpolate_sql(sql) + instance_eval("%@#{sql.gsub('@', '\@')}@", __FILE__, __LINE__) + end + + private + + def allocate_aliases + @aliased_prefix = "t#{ join_dependency.join_parts.size }" + @aliased_table_name = aliased_table_name_for(table_name) + + 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 + + def process_conditions(conditions, table_name) + Arel.sql(interpolate_sql(sanitize_sql(conditions, table_name))) + end + + def join_target_table(relation, *conditions) + relation = relation.join(target_table, join_type) + + # 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] + + sti_condition = sti_column.eq(active_record.sti_name) + active_record.descendants.each do |subclass| + sti_condition = sti_condition.or(sti_column.eq(subclass.sti_name)) + end + + conditions << sti_condition + end + + # If the reflection has conditions, add them + if options[:conditions] + conditions << process_conditions(options[:conditions], aliased_table_name) + end + + relation = relation.on(*conditions) + end + + def join_has_and_belongs_to_many_to(relation) + join_table = Arel::Table.new( + options[:join_table], :engine => arel_engine, + :as => @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]) + ) + 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 + 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, :engine => arel_engine, + :as => @aliased_join_table_name + ) + + jt_conditions = [] + jt_foreign_key = first_key = second_key = nil + + if through_reflection.options[:as] # has_many :through against a polymorphic join + as_key = through_reflection.options[:as].to_s + jt_foreign_key = as_key + '_id' + + jt_conditions << + join_table[as_key + '_type']. + eq(parent.active_record.base_class.name) + else + jt_foreign_key = through_reflection.primary_key_name + 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.options[:foreign_type]]. + eq(reflection.options[:source_type]) + else + second_key = source_reflection.primary_key_name + end + end + + jt_conditions << + parent_table[parent.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]), + 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.primary_key_name + 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 + end +end diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_base.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_base.rb new file mode 100644 index 0000000000..ed05003f66 --- /dev/null +++ b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_base.rb @@ -0,0 +1,34 @@ +module ActiveRecord + module Associations + module ClassMethods + class JoinDependency # :nodoc: + class JoinBase < JoinPart # :nodoc: + # Extra joins provided when the JoinDependency was created + attr_reader :table_joins + + def initialize(active_record, joins = nil) + super(active_record) + @table_joins = joins + end + + def ==(other) + other.class == self.class && + other.active_record == active_record + end + + def aliased_prefix + "t0" + end + + def table + Arel::Table.new(table_name, :engine => arel_engine, :columns => active_record.columns) + end + + def aliased_table_name + active_record.table_name + end + end + end + end + end +end diff --git a/activerecord/lib/active_record/associations/class_methods/join_dependency/join_part.rb b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_part.rb new file mode 100644 index 0000000000..64d751344d --- /dev/null +++ b/activerecord/lib/active_record/associations/class_methods/join_dependency/join_part.rb @@ -0,0 +1,76 @@ +module ActiveRecord + module Associations + module ClassMethods + class JoinDependency # :nodoc: + # A JoinPart represents a part of a JoinDependency. It is an abstract class, inherited + # by JoinBase and JoinAssociation. A JoinBase represents the Active Record which + # everything else is being joined onto. A JoinAssociation represents an association which + # is joining to the base. A JoinAssociation may result in more than one actual join + # operations (for example a has_and_belongs_to_many JoinAssociation would result in + # two; one for the join table and one for the target table). + class JoinPart # :nodoc: + # The Active Record class which this join part is associated 'about'; for a JoinBase + # this is the actual base model, for a JoinAssociation this is the target model of the + # association. + attr_reader :active_record + + delegate :table_name, :column_names, :primary_key, :reflections, :sanitize_sql, :arel_engine, :to => :active_record + + def initialize(active_record) + @active_record = active_record + @cached_record = {} + end + + def ==(other) + raise NotImplementedError + end + + # An Arel::Table for the active_record + def table + raise NotImplementedError + end + + # The prefix to be used when aliasing columns in the active_record's table + def aliased_prefix + raise NotImplementedError + end + + # The alias for the active_record's table + def aliased_table_name + raise NotImplementedError + end + + # The alias for the primary key of the active_record's table + def aliased_primary_key + "#{aliased_prefix}_r0" + end + + # An array of [column_name, alias] pairs for the table + def column_names_with_alias + unless defined?(@column_names_with_alias) + @column_names_with_alias = [] + + ([primary_key] + (column_names - [primary_key])).each_with_index do |column_name, i| + @column_names_with_alias << [column_name, "#{aliased_prefix}_r#{i}"] + end + end + + @column_names_with_alias + end + + def extract_record(row) + Hash[column_names_with_alias.map{|cn, an| [cn, row[an]]}] + end + + def record_id(row) + row[aliased_primary_key] + end + + def instantiate(row) + @cached_record[record_id(row)] ||= active_record.send(:instantiate, extract_record(row)) + end + end + end + end + end +end |