previous_changes() Instance Public methods Returns a hash of attributes that

changed_attributes() Instance Public methods Returns a hash of the attributes

validates_presence_of(*attr_names) Instance Public methods Validates that the

param_key(record_or_class) Class Public methods Returns string to use for params

set(key, value) Instance Public methods Set messages for key to

validates(*attributes) Instance Public methods This method is a shortcut to

as_json(options=nil) Instance Public methods Returns a

valid?(context = nil) Instance Public methods Runs all the specified validations

eager_load!() Class Public methods

=~(regexp) Instance Public methods Equivalent to String#=~. Match