Module ActiveModel::AttributeMethods::ClassMethods
In: lib/active_model/attribute_methods.rb

Methods

Classes and Modules

Class ActiveModel::AttributeMethods::ClassMethods::AttributeMethodMatcher

Public Instance methods

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:

  AttributePerson.primary_key
  # => "sysid"
  AttributePerson.inheritance_column = 'address'
  AttributePerson.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

Removes all the previously dynamically defined methods from the class

Protected Instance methods

[Validate]