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module ActiveRecord
# = Active Record Through Association
module Associations
module ThroughAssociation
def scoped
with_scope(@scope) do
@reflection.klass.scoped &
@reflection.through_reflection.klass.scoped
end
end
def stale_target?
if @target && @reflection.through_reflection.macro == :belongs_to && defined?(@through_foreign_key)
previous_key = @through_foreign_key.to_s
current_key = @owner.send(@reflection.through_reflection.foreign_key).to_s
previous_key != current_key
else
false
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
# This scope affects the creation of the associated records (not the join records). At the
# moment we only support creating on a :through association when the source reflection is a
# belongs_to. Thus it's not necessary to set a foreign key on the associated record(s), so
# this scope has can legitimately be empty.
def construct_create_scope
{ }
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
def construct_owner_conditions
super(aliased_through_table, @reflection.through_reflection)
end
def construct_select
@reflection.options[:select] ||
@reflection.options[:uniq] && "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.source_reflection.options[:primary_key] ||
@reflection.klass.primary_key
source_primary_key = @reflection.source_reflection.foreign_key
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.foreign_key
source_primary_key = @reflection.source_reflection.options[: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 :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 = {
@reflection.source_reflection.foreign_key =>
associate.send(@reflection.source_reflection.association_primary_key)
}
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
def update_stale_state
if @reflection.through_reflection.macro == :belongs_to
@through_foreign_key = @owner.send(@reflection.through_reflection.foreign_key)
end
end
end
end
end
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