module ActiveRecord
# = Active Record Through Association Scope
module Associations
module ThroughAssociationScope
def scoped
with_scope(@scope) do
@reflection.klass.scoped &
@reflection.through_reflection.klass.scoped
end
end
protected
def construct_find_scope
{
:conditions => construct_conditions,
:joins => construct_joins,
:include => @reflection.options[:include] || @reflection.source_reflection.options[:include],
:select => construct_select,
:order => @reflection.options[:order],
:limit => @reflection.options[:limit],
:readonly => @reflection.options[:readonly]
}
end
def construct_create_scope
construct_owner_attributes(@reflection)
end
def aliased_through_table
name = @reflection.through_reflection.table_name
@reflection.table_name == name ?
@reflection.through_reflection.klass.arel_table.alias(name + "_join") :
@reflection.through_reflection.klass.arel_table
end
# Build SQL conditions from attributes, qualified by table name.
def construct_conditions
table = aliased_through_table
conditions = construct_quoted_owner_attributes(@reflection.through_reflection).map do |attr, value|
table[attr].eq(value)
end
conditions << Arel.sql(sql_conditions) if sql_conditions
table.create_and(conditions)
end
# Associate attributes pointing to owner, quoted.
def construct_quoted_owner_attributes(reflection)
if as = reflection.options[:as]
{ "#{as}_id" => @owner.id,
"#{as}_type" => @owner.class.base_class.name }
elsif reflection.macro == :belongs_to
{ reflection.klass.primary_key => @owner[reflection.primary_key_name] }
else
{ reflection.primary_key_name => @owner.id }
end
end
def construct_from
@reflection.table_name
end
def construct_select(custom_select = nil)
distinct = "DISTINCT " if @reflection.options[:uniq]
custom_select || @reflection.options[:select] || "#{distinct}#{@reflection.quoted_table_name}.*"
end
def construct_joins
right = aliased_through_table
left = @reflection.klass.arel_table
conditions = []
if @reflection.source_reflection.macro == :belongs_to
reflection_primary_key = @reflection.klass.primary_key
source_primary_key = @reflection.source_reflection.primary_key_name
if @reflection.options[:source_type]
column = @reflection.source_reflection.options[:foreign_type]
conditions <<
right[column].eq(@reflection.options[:source_type])
end
else
reflection_primary_key = @reflection.source_reflection.primary_key_name
source_primary_key = @reflection.through_reflection.klass.primary_key
if @reflection.source_reflection.options[:as]
column = "#{@reflection.source_reflection.options[:as]}_type"
conditions <<
left[column].eq(@reflection.through_reflection.klass.name)
end
end
conditions <<
left[reflection_primary_key].eq(right[source_primary_key])
right.create_join(
right,
right.create_on(right.create_and(conditions)))
end
# Construct attributes for associate pointing to owner.
def construct_owner_attributes(reflection)
if as = reflection.options[:as]
{ "#{as}_id" => @owner.id,
"#{as}_type" => @owner.class.base_class.name }
else
{ reflection.primary_key_name => @owner.id }
end
end
# Construct attributes for :through pointing to owner and associate.
def construct_join_attributes(associate)
# TODO: revisit this to allow it for deletion, supposing dependent option is supported
raise ActiveRecord::HasManyThroughCantAssociateThroughHasOneOrManyReflection.new(@owner, @reflection) if [:has_one, :has_many].include?(@reflection.source_reflection.macro)
join_attributes = construct_owner_attributes(@reflection.through_reflection).merge(@reflection.source_reflection.primary_key_name => associate.id)
if @reflection.options[:source_type]
join_attributes.merge!(@reflection.source_reflection.options[:foreign_type] => associate.class.base_class.name)
end
if @reflection.through_reflection.options[:conditions].is_a?(Hash)
join_attributes.merge!(@reflection.through_reflection.options[:conditions])
end
join_attributes
end
def conditions
@conditions = build_conditions unless defined?(@conditions)
@conditions
end
def build_conditions
association_conditions = @reflection.options[:conditions]
through_conditions = build_through_conditions
source_conditions = @reflection.source_reflection.options[:conditions]
uses_sti = !@reflection.through_reflection.klass.descends_from_active_record?
if association_conditions || through_conditions || source_conditions || uses_sti
all = []
[association_conditions, source_conditions].each do |conditions|
all << interpolate_sql(sanitize_sql(conditions)) if conditions
end
all << through_conditions if through_conditions
all << build_sti_condition if uses_sti
all.map { |sql| "(#{sql})" } * ' AND '
end
end
def build_through_conditions
conditions = @reflection.through_reflection.options[:conditions]
if conditions.is_a?(Hash)
interpolate_sql(@reflection.through_reflection.klass.send(:sanitize_sql, conditions)).gsub(
@reflection.quoted_table_name,
@reflection.through_reflection.quoted_table_name)
elsif conditions
interpolate_sql(sanitize_sql(conditions))
end
end
def build_sti_condition
@reflection.through_reflection.klass.send(:type_condition).to_sql
end
alias_method :sql_conditions, :conditions
end
end
end