diff options
Diffstat (limited to 'activerecord/lib/active_record/associations/class_methods/join_dependency.rb')
-rw-r--r-- | activerecord/lib/active_record/associations/class_methods/join_dependency.rb | 233 |
1 files changed, 233 insertions, 0 deletions
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..cb3edafab1 --- /dev/null +++ b/activerecord/lib/active_record/associations/class_methods/join_dependency.rb @@ -0,0 +1,233 @@ +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, :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 + 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 columns + join_parts.collect { |join_part| + table = join_part.aliased_table + join_part.column_names_with_alias.collect{ |column_name, aliased_name| + table[column_name].as Arel.sql(aliased_name) + } + }.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 = {} + + records = rows.map { |model| + primary_id = model[primary_key] + parent = parents[primary_id] ||= join_base.instantiate(model) + construct(parent, @associations, join_associations, model) + parent + }.uniq + + remove_duplicate_results!(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_by { |a| a.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.association_cache.key?(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) + 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(:association_proxy, join_part.reflection.name) + association_proxy.target = association + association_proxy.send(:set_inverse_instance, association) + end + end + end + end +end |