Module | ActiveModel::AttributeMethods::ClassMethods |
In: |
lib/active_model/attribute_methods.rb
|
Declares a method available for all attributes with the given prefix and suffix. Uses method_missing and respond_to? to rewrite the method.
#{prefix}#{attr}#{suffix}(*args, &block)
to
#{prefix}attribute#{suffix}(#{attr}, *args, &block)
An #{prefix}attribute#{suffix} instance method must exist and accept at least the attr argument.
For example:
class Person include ActiveModel::AttributeMethods attr_accessor :name attribute_method_affix :prefix => 'reset_', :suffix => '_to_default!' define_attribute_methods [:name] private def reset_attribute_to_default!(attr) ... end end person = Person.new person.name # => 'Gem' person.reset_name_to_default! person.name # => 'Gemma'
Declares a method available for all attributes with the given prefix. Uses method_missing and respond_to? to rewrite the method.
#{prefix}#{attr}(*args, &block)
to
#{prefix}attribute(#{attr}, *args, &block)
An instance method #{prefix}attribute must exist and accept at least the attr argument.
For example:
class Person include ActiveModel::AttributeMethods attr_accessor :name attribute_method_prefix 'clear_' define_attribute_methods [:name] private def clear_attribute(attr) send("#{attr}=", nil) end end person = Person.new person.name = "Bob" person.name # => "Bob" person.clear_name person.name # => nil
Declares a method available for all attributes with the given suffix. Uses method_missing and respond_to? to rewrite the method.
#{attr}#{suffix}(*args, &block)
to
attribute#{suffix}(#{attr}, *args, &block)
An attribute#{suffix} instance method must exist and accept at least the attr argument.
For example:
class Person include ActiveModel::AttributeMethods attr_accessor :name attribute_method_suffix '_short?' define_attribute_methods [:name] private def attribute_short?(attr) send(attr).length < 5 end end person = Person.new person.name = "Bob" person.name # => "Bob" person.name_short? # => true
Defines an "attribute" method (like inheritance_column or table_name). A new (class) method will be created with the given name. If a value is specified, the new method will return that value (as a string). Otherwise, the given block will be used to compute the value of the method.
The original method will be aliased, with the new name being prefixed with "original_". This allows the new method to access the original value.
Example:
class Person include ActiveModel::AttributeMethods cattr_accessor :primary_key cattr_accessor :inheritance_column define_attr_method :primary_key, "sysid" define_attr_method( :inheritance_column ) do original_inheritance_column + "_id" end end
Provides you with:
Person.primary_key # => "sysid" Person.inheritance_column = 'address' Person.inheritance_column # => 'address_id'
Declares the attributes that should be prefixed and suffixed by ActiveModel::AttributeMethods.
To use, pass in an array of attribute names (as strings or symbols), be sure to declare define_attribute_methods after you define any prefix, suffix or affix methods, or they will not hook in.
class Person include ActiveModel::AttributeMethods attr_accessor :name, :age, :address attribute_method_prefix 'clear_' # Call to define_attribute_methods must appear after the # attribute_method_prefix, attribute_method_suffix or # attribute_method_affix declares. define_attribute_methods [:name, :age, :address] private def clear_attribute(attr) ... end end