diff options
Diffstat (limited to 'activerecord/lib/active_record/associations/association_scope.rb')
-rw-r--r-- | activerecord/lib/active_record/associations/association_scope.rb | 120 |
1 files changed, 120 insertions, 0 deletions
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 |