diff options
Diffstat (limited to 'activerecord/lib/active_record/attribute_decorators.rb')
-rw-r--r-- | activerecord/lib/active_record/attribute_decorators.rb | 48 |
1 files changed, 35 insertions, 13 deletions
diff --git a/activerecord/lib/active_record/attribute_decorators.rb b/activerecord/lib/active_record/attribute_decorators.rb index 7d0ae32411..c39e9ce4c5 100644 --- a/activerecord/lib/active_record/attribute_decorators.rb +++ b/activerecord/lib/active_record/attribute_decorators.rb @@ -8,12 +8,34 @@ module ActiveRecord end module ClassMethods # :nodoc: + # This method is an internal API used to create class macros such as + # +serialize+, and features like time zone aware attributes. + # + # Used to wrap the type of an attribute in a new type. + # When the schema for a model is loaded, attributes with the same name as + # +column_name+ will have their type yielded to the given block. The + # return value of that block will be used instead. + # + # Subsequent calls where +column_name+ and +decorator_name+ are the same + # will override the previous decorator, not decorate twice. This can be + # used to create idempotent class macros like +serialize+ def decorate_attribute_type(column_name, decorator_name, &block) matcher = ->(name, _) { name == column_name.to_s } key = "_#{column_name}_#{decorator_name}" decorate_matching_attribute_types(matcher, key, &block) end + # This method is an internal API used to create higher level features like + # time zone aware attributes. + # + # When the schema for a model is loaded, +matcher+ will be called for each + # attribute with its name and type. If the matcher returns a truthy value, + # the type will then be yielded to the given block, and the return value + # of that block will replace the type. + # + # Subsequent calls to this method with the same value for +decorator_name+ + # will replace the previous decorator, not decorate twice. This can be + # used to ensure that class macros are idempotent. def decorate_matching_attribute_types(matcher, decorator_name, &block) reload_schema_from_cache decorator_name = decorator_name.to_s @@ -24,13 +46,13 @@ module ActiveRecord private - def load_schema! - super - attribute_types.each do |name, type| - decorated_type = attribute_type_decorations.apply(name, type) - define_attribute(name, decorated_type) + def load_schema! + super + attribute_types.each do |name, type| + decorated_type = attribute_type_decorations.apply(name, type) + define_attribute(name, decorated_type) + end end - end end class TypeDecorator # :nodoc: @@ -53,15 +75,15 @@ module ActiveRecord private - def decorators_for(name, type) - matching(name, type).map(&:last) - end + def decorators_for(name, type) + matching(name, type).map(&:last) + end - def matching(name, type) - @decorations.values.select do |(matcher, _)| - matcher.call(name, type) + def matching(name, type) + @decorations.values.select do |(matcher, _)| + matcher.call(name, type) + end end - end end end end |