Move JoinDependency and friends from ActiveRecord::Associations::ClassMethods to just ActiveRecord::Associations

1 files changed, 231 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/associations/join_dependency.rb b/activerecord/lib/active_record/associations/join_dependency.rb
new file mode 100644
index 0000000000..c7c3cf521c
--- /dev/null
+++ b/activerecord/lib/active_record/associations/join_dependency.rb
@@ -0,0 +1,231 @@
+module ActiveRecord
+  module Associations
+    class JoinDependency # :nodoc:
+      autoload :JoinPart,        'active_record/associations/join_dependency/join_part'
+      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
+
+      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 |association_name, assoc|
+            association = construct(parent, association_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
+            other = record.association(join_part.reflection.name)
+            other.loaded!
+            other.target.push(association)
+            other.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)
+        other = record.association(join_part.reflection.name)
+        other.target = association
+        other.set_inverse_instance(association)
+      end
+    end
+  end
+end