module ActiveRecord
module Associations
class HasManyThroughAssociation < HasManyAssociation #:nodoc:
def initialize(owner, reflection)
reflection.check_validity!
super
end
alias_method :new, :build
def create!(attrs = nil)
transaction do
self << (object = attrs ? @reflection.klass.send(:with_scope, :create => attrs) { @reflection.create_association! } : @reflection.create_association!)
object
end
end
def create(attrs = nil)
transaction do
self << (object = attrs ? @reflection.klass.send(:with_scope, :create => attrs) { @reflection.create_association } : @reflection.create_association)
object
end
end
# Returns the size of the collection by executing a SELECT COUNT(*) query if the collection hasn't been loaded and
# calling collection.size if it has. If it's more likely than not that the collection does have a size larger than zero,
# and you need to fetch that collection afterwards, it'll take one fewer SELECT query if you use #length.
def size
return @owner.send(:read_attribute, cached_counter_attribute_name) if has_cached_counter?
return @target.size if loaded?
return count
end
protected
def target_reflection_has_associated_record?
if @reflection.through_reflection.macro == :belongs_to && @owner[@reflection.through_reflection.primary_key_name].blank?
false
else
true
end
end
def construct_find_options!(options)
options[:select] = construct_select(options[:select])
options[:from] ||= construct_from
options[:joins] = construct_joins(options[:joins])
options[:include] = @reflection.source_reflection.options[:include] if options[:include].nil?
end
def insert_record(record, force = true, validate = true)
if record.new_record?
if force
record.save!
else
return false unless record.save(validate)
end
end
through_reflection = @reflection.through_reflection
klass = through_reflection.klass
@owner.send(@reflection.through_reflection.name).proxy_target << klass.send(:with_scope, :create => construct_join_attributes(record)) { through_reflection.create_association! }
end
# TODO - add dependent option support
def delete_records(records)
klass = @reflection.through_reflection.klass
records.each do |associate|
klass.delete_all(construct_join_attributes(associate))
end
end
def find_target
return [] unless target_reflection_has_associated_record?
@reflection.klass.find(:all,
:select => construct_select,
:conditions => construct_conditions,
:from => construct_from,
:joins => construct_joins,
:order => @reflection.options[:order],
:limit => @reflection.options[:limit],
:group => @reflection.options[:group],
:readonly => @reflection.options[:readonly],
:include => @reflection.options[:include] || @reflection.source_reflection.options[:include]
)
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.to_s }
else
{ reflection.primary_key_name => @owner.id }
end
end
# Construct attributes for :through pointing to owner and associate.
def construct_join_attributes(associate)
# TODO: revist this to allow it for deletion, supposing dependent option is supported
raise ActiveRecord::HasManyThroughCantAssociateThroughHasManyReflection.new(@owner, @reflection) if @reflection.source_reflection.macro == :has_many
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.to_s)
end
join_attributes
end
# Associate attributes pointing to owner, quoted.
def construct_quoted_owner_attributes(reflection)
if as = reflection.options[:as]
{ "#{as}_id" => owner_quoted_id,
"#{as}_type" => reflection.klass.quote_value(
@owner.class.base_class.name.to_s,
reflection.klass.columns_hash["#{as}_type"]) }
elsif reflection.macro == :belongs_to
{ reflection.klass.primary_key => @owner[reflection.primary_key_name] }
else
{ reflection.primary_key_name => owner_quoted_id }
end
end
# Build SQL conditions from attributes, qualified by table name.
def construct_conditions
table_name = @reflection.through_reflection.quoted_table_name
conditions = construct_quoted_owner_attributes(@reflection.through_reflection).map do |attr, value|
"#{table_name}.#{attr} = #{value}"
end
conditions << sql_conditions if sql_conditions
"(" + conditions.join(') AND (') + ")"
end
def construct_from
@reflection.quoted_table_name
end
def construct_select(custom_select = nil)
distinct = "DISTINCT " if @reflection.options[:uniq]
selected = custom_select || @reflection.options[:select] || "#{distinct}#{@reflection.quoted_table_name}.*"
end
def construct_joins(custom_joins = nil)
polymorphic_join = nil
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]
polymorphic_join = "AND %s.%s = %s" % [
@reflection.through_reflection.quoted_table_name, "#{@reflection.source_reflection.options[:foreign_type]}",
@owner.class.quote_value(@reflection.options[:source_type])
]
end
else
reflection_primary_key = @reflection.source_reflection.primary_key_name
source_primary_key = @reflection.klass.primary_key
if @reflection.source_reflection.options[:as]
polymorphic_join = "AND %s.%s = %s" % [
@reflection.quoted_table_name, "#{@reflection.source_reflection.options[:as]}_type",
@owner.class.quote_value(@reflection.through_reflection.klass.name)
]
end
end
"INNER JOIN %s ON %s.%s = %s.%s %s #{@reflection.options[:joins]} #{custom_joins}" % [
@reflection.through_reflection.quoted_table_name,
@reflection.quoted_table_name, reflection_primary_key,
@reflection.through_reflection.quoted_table_name, source_primary_key,
polymorphic_join
]
end
def construct_scope
{ :create => construct_owner_attributes(@reflection),
:find => { :from => construct_from,
:conditions => construct_conditions,
:joins => construct_joins,
:include => @reflection.options[:include],
:select => construct_select,
:order => @reflection.options[:order],
:limit => @reflection.options[:limit],
:readonly => @reflection.options[:readonly],
} }
end
def construct_sql
case
when @reflection.options[:finder_sql]
@finder_sql = interpolate_sql(@reflection.options[:finder_sql])
@finder_sql = "#{@reflection.quoted_table_name}.#{@reflection.primary_key_name} = #{owner_quoted_id}"
@finder_sql << " AND (#{conditions})" if conditions
else
@finder_sql = construct_conditions
end
if @reflection.options[:counter_sql]
@counter_sql = interpolate_sql(@reflection.options[:counter_sql])
elsif @reflection.options[:finder_sql]
# replace the SELECT clause with COUNT(*), preserving any hints within /* ... */
@reflection.options[:counter_sql] = @reflection.options[:finder_sql].sub(/SELECT (\/\*.*?\*\/ )?(.*)\bFROM\b/im) { "SELECT #{$1}COUNT(*) FROM" }
@counter_sql = interpolate_sql(@reflection.options[:counter_sql])
else
@counter_sql = @finder_sql
end
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(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)
end
alias_method :sql_conditions, :conditions
def has_cached_counter?
@owner.attribute_present?(cached_counter_attribute_name)
end
def cached_counter_attribute_name
"#{@reflection.name}_count"
end
end
end
end