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-rw-r--r--activerecord/lib/active_record/associations/join_dependency.rb48
1 files changed, 37 insertions, 11 deletions
diff --git a/activerecord/lib/active_record/associations/join_dependency.rb b/activerecord/lib/active_record/associations/join_dependency.rb
index f40368cfeb..5aa17e5fbb 100644
--- a/activerecord/lib/active_record/associations/join_dependency.rb
+++ b/activerecord/lib/active_record/associations/join_dependency.rb
@@ -5,10 +5,31 @@ 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, :alias_tracker, :active_record
-
+ attr_reader :join_parts, :reflections, :alias_tracker, :base_klass
+
+ # base is the base class on which operation is taking place.
+ # associations is the list of associations which are joined using hash, symbol or array.
+ # joins is the list of all string join commnads and arel nodes.
+ #
+ # Example :
+ #
+ # class Physician < ActiveRecord::Base
+ # has_many :appointments
+ # has_many :patients, through: :appointments
+ # end
+ #
+ # If I execute `@physician.patients.to_a` then
+ # base #=> Physician
+ # associations #=> []
+ # joins #=> [#<Arel::Nodes::InnerJoin: ...]
+ #
+ # However if I execute `Physician.joins(:appointments).to_a` then
+ # base #=> Physician
+ # associations #=> [:appointments]
+ # joins #=> []
+ #
def initialize(base, associations, joins)
- @active_record = base
+ @base_klass = base
@table_joins = joins
@join_parts = [JoinBase.new(base)]
@associations = {}
@@ -27,13 +48,19 @@ module ActiveRecord
end
def join_associations
- join_parts.last(join_parts.length - 1)
+ join_parts.drop 1
end
def join_base
join_parts.first
end
+ def join_relation(relation)
+ join_associations.inject(relation) do |rel,association|
+ association.join_relation(rel)
+ end
+ end
+
def columns
join_parts.collect { |join_part|
table = join_part.aliased_table
@@ -54,10 +81,12 @@ module ActiveRecord
parent
}.uniq
- remove_duplicate_results!(active_record, records, @associations)
+ remove_duplicate_results!(base_klass, records, @associations)
records
end
+ protected
+
def remove_duplicate_results!(base, records, associations)
case associations
when Symbol, String
@@ -88,8 +117,6 @@ module ActiveRecord
end
end
- protected
-
def cache_joined_association(association)
associations = []
parent = association.parent
@@ -104,12 +131,11 @@ module ActiveRecord
ref[association.reflection.name] ||= {}
end
- def build(associations, parent = nil, join_type = Arel::InnerJoin)
- parent ||= join_parts.last
+ def build(associations, parent = join_parts.last, join_type = Arel::InnerJoin)
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?"
+ reflection = parent.reflections[associations.intern] or
+ raise ConfigurationError, "Association named '#{ associations }' was not found on #{ parent.base_klass.name }; perhaps you misspelled it?"
unless join_association = find_join_association(reflection, parent)
@reflections << reflection
join_association = build_join_association(reflection, parent)