diff options
Diffstat (limited to 'activerecord/lib/active_record/enum.rb')
| -rw-r--r-- | activerecord/lib/active_record/enum.rb | 128 |
1 files changed, 111 insertions, 17 deletions
diff --git a/activerecord/lib/active_record/enum.rb b/activerecord/lib/active_record/enum.rb index 837989aaa7..4aa323fb00 100644 --- a/activerecord/lib/active_record/enum.rb +++ b/activerecord/lib/active_record/enum.rb @@ -1,5 +1,6 @@ module ActiveRecord - # Declare an enum attribute where the values map to integers in the database, but can be queried by name. Example: + # Declare an enum attribute where the values map to integers in the database, + # but can be queried by name. Example: # # class Conversation < ActiveRecord::Base # enum status: [ :active, :archived ] @@ -18,6 +19,15 @@ module ActiveRecord # # conversation.update! status: 1 # conversation.status = "archived" # + # # conversation.update! status: nil + # conversation.status = nil + # conversation.status.nil? # => true + # conversation.status # => nil + # + # Scopes based on the allowed values of the enum field will be provided + # as well. With the above example, it will create an +active+ and +archived+ + # scope. + # # You can set the default value from the database declaration, like: # # create_table :conversations do |t| @@ -44,46 +54,76 @@ module ActiveRecord # remove unused values, the explicit +Hash+ syntax should be used. # # In rare circumstances you might need to access the mapping directly. - # The mappings are exposed through a constant with the attributes name: + # The mappings are exposed through a class method with the pluralized attribute + # name: + # + # Conversation.statuses # => { "active" => 0, "archived" => 1 } # - # Conversation::STATUS # => { "active" => 0, "archived" => 1 } + # Use that class method when you need to know the ordinal value of an enum: # - # Use that constant when you need to know the ordinal value of an enum: + # Conversation.where("status <> ?", Conversation.statuses[:archived]) # - # Conversation.where("status <> ?", Conversation::STATUS[:archived]) + # Where conditions on an enum attribute must use the ordinal value of an enum. module Enum + DEFINED_ENUMS = {} # :nodoc: + + def enum_mapping_for(attr_name) # :nodoc: + DEFINED_ENUMS[attr_name.to_s] + end + def enum(definitions) klass = self definitions.each do |name, values| - # DIRECTION = { } - enum_values = _enum_methods_module.const_set name.to_s.upcase, ActiveSupport::HashWithIndifferentAccess.new + # statuses = { } + enum_values = ActiveSupport::HashWithIndifferentAccess.new name = name.to_sym + # def self.statuses statuses end + detect_enum_conflict!(name, name.to_s.pluralize, true) + klass.singleton_class.send(:define_method, name.to_s.pluralize) { enum_values } + _enum_methods_module.module_eval do - # def direction=(value) self[:direction] = DIRECTION[value] end + # def status=(value) self[:status] = statuses[value] end + klass.send(:detect_enum_conflict!, name, "#{name}=") define_method("#{name}=") { |value| - unless enum_values.has_key?(value) + if enum_values.has_key?(value) || value.blank? + self[name] = enum_values[value] + elsif enum_values.has_value?(value) + # Assigning a value directly is not a end-user feature, hence it's not documented. + # This is used internally to make building objects from the generated scopes work + # as expected, i.e. +Conversation.archived.build.archived?+ should be true. + self[name] = value + else raise ArgumentError, "'#{value}' is not a valid #{name}" end - self[name] = enum_values[value] } - # def direction() DIRECTION.key self[:direction] end + # def status() statuses.key self[:status] end + klass.send(:detect_enum_conflict!, name, name) define_method(name) { enum_values.key self[name] } + # def status_before_type_cast() statuses.key self[:status] end + klass.send(:detect_enum_conflict!, name, "#{name}_before_type_cast") + define_method("#{name}_before_type_cast") { enum_values.key self[name] } + pairs = values.respond_to?(:each_pair) ? values.each_pair : values.each_with_index pairs.each do |value, i| enum_values[value] = i - # scope :incoming, -> { where direction: 0 } - klass.scope value, -> { klass.where name => i } - - # def incoming?() direction == 0 end + # def active?() status == 0 end + klass.send(:detect_enum_conflict!, name, "#{value}?") define_method("#{value}?") { self[name] == i } - # def incoming! update! direction: :incoming end + # def active!() update! status: :active end + klass.send(:detect_enum_conflict!, name, "#{value}!") define_method("#{value}!") { update! name => value } + + # scope :active, -> { where status: 0 } + klass.send(:detect_enum_conflict!, name, value, true) + klass.scope value, -> { klass.where name => i } end + + DEFINED_ENUMS[name.to_s] = enum_values end end end @@ -91,10 +131,64 @@ module ActiveRecord private def _enum_methods_module @_enum_methods_module ||= begin - mod = Module.new + mod = Module.new do + private + def save_changed_attribute(attr_name, value) + if (mapping = self.class.enum_mapping_for(attr_name)) + if attribute_changed?(attr_name) + old = changed_attributes[attr_name] + + if mapping[old] == value + changed_attributes.delete(attr_name) + end + else + old = clone_attribute_value(:read_attribute, attr_name) + + if old != value + changed_attributes[attr_name] = mapping.key old + end + end + else + super + end + end + end include mod mod end end + + ENUM_CONFLICT_MESSAGE = \ + "You tried to define an enum named \"%{enum}\" on the model \"%{klass}\", but " \ + "this will generate a %{type} method \"%{method}\", which is already defined " \ + "by %{source}." + + def detect_enum_conflict!(enum_name, method_name, klass_method = false) + if klass_method && dangerous_class_method?(method_name) + raise ArgumentError, ENUM_CONFLICT_MESSAGE % { + enum: enum_name, + klass: self.name, + type: 'class', + method: method_name, + source: 'Active Record' + } + elsif !klass_method && dangerous_attribute_method?(method_name) + raise ArgumentError, ENUM_CONFLICT_MESSAGE % { + enum: enum_name, + klass: self.name, + type: 'instance', + method: method_name, + source: 'Active Record' + } + elsif !klass_method && method_defined_within?(method_name, _enum_methods_module, Module) + raise ArgumentError, ENUM_CONFLICT_MESSAGE % { + enum: enum_name, + klass: self.name, + type: 'instance', + method: method_name, + source: 'another enum' + } + end + end end end |