// Describe the validation function you want.
var validate = Ratify.getModelValidator({
  username: {presence: true},
  password: {presence: true, length: {minimum: 5}},
  passwordConfirmation: {confirmation: 'password'},
  email: {format: /^\w+@\w+\.\w+$/}
});

// Bring your own model attributes.
var attrs = {username: 'brian', password: 'wat?', passwordConfirmation: '', email: 'not-an-email!'};

// Validate all attributes.
validate(attrs)
  .then(function() {
    // All attributes are valid
    console.log('all OK!');
  })
  .catch(Ratify.ValidationError, function(e) {
    // Validation(s) failed. See which attributes had errors by inspecting e.errors.
    // In this case, e.errors is {password: {length: true}, passwordConfirmation: {confirmation: true}, email: {format: true}
    console.log(e.errors);
  });

// Validate individual attributes
validate(attrs, 'email')
  .then(function() {
    // Attribute is valid
    console.log('email OK');
  })
  .catch(Ratify.ValidationError, function(e) {
    // Attribute is invalid
    // e.errors is {email: {format: true}}
    console.log(e.errors);
  });