valid?(context = nil)
Instance Public methods
Runs all the validations within the specified context. Returns
true if no errors are found, false otherwise.
If the argument is false (default is nil), the
context is set to :create if new_record? is
true, and to :update if it is not.
Validations with no :on option
will run no matter the context. Validations
with some :on option will only run in the specified context.