Assent

This is inspired heavily by the c# Fluent Validation library.

Install

bower install assent

Usage

Defining models and their validators

function Address() {
  this.line1 = null;
  this.postCode = null;
}

var addressValidator = new Validator(function (c) {
  c.ruleFor('line1', function (f) {
    f.notEmpty()
      .withMessage('line1 is required');
  })
});

addressValidator.applyTo(Address);

addressValidator.applyTo(Address); sets the validator to Address's prototype.

function UserCreate() {
  this.username = null;
  this.firstName = null;
  this.lastName = null;
  this.age = null;
  this.dob = null;
  this.password = null;
  this.passwordConfirmation = null;
  this.address = new Address();
  this.tags = [];
  this.categories = [];
}

var userValidator = new Validator(function (c) {
  c.ruleFor('username', function (f) {
    f.notEmpty()
      .withMessage('username is required');
  });

  c.ruleFor('firstName', function (f) {
    f.notEmpty()
      .withMessage('firstName is required');
    f.minLength(10)
      .withMessage('firstName cannot be shorter than {|}')
    f.maxLength(20)
      .withMessage('firstName cannot be longer than {|}')
  });

  c.ruleFor('lastName', function (f) {
    f.notEmpty()
      .withMessage('lastName is required');
  });

  c.ruleFor('age', function (f) {
    f.min(18)
      .withMessage('user must be at least {|}');
    f.max(80)
      .withMessage('user must be less than {|}')
    f.notEmpty()
      .when(function (obj) { return obj.dob === null ;});
  });

  c.ruleFor('password', function (f) {
    f.notEmpty()
      .withMessage('password is required');
  });

  c.ruleFor('passwordConfirmation', function (f) {
    f.notEmpty()
      .withMessage('password confirmation is required');

    f.matches(function (obj) { return obj.password; })
      .withMessage('password confirmation must match password');
  });

  c.ruleFor('tags', function (f) {
    f.notEmpty()
      .withMessage('you must provide at least one tag');
  });

  c.ruleFor('categories', function (f) {
    f.notEmpty()
      .withMessage('category cannot be blank')
      .validateCollection();
  });
});

userValidator.applyTo(UserCreate);

Validating and instance of your model

var user = new UserCreate();
var result = user.$validate();

Format of the validation result object

For Fields

result.firstName.notEmpty.error (true|false) result.firstName.notEmpty.message set on error

For Arrays using foreach validation

This is for when validationCollection is not called, it will validate each element in the array rather than the array itself. The default behaviour is to validate the array.

result.firstName.notEmpty.error (true|false) result.firstName.notEmpty[0].error (true|false) result.firstName.notEmpty[0].message (error message if applicable)

Integration

Angular

TODO

• recursive validation
• support returning promises from rule function
• and perhaps some promise support for messages
• and what the hey, promises for the when calls too! Promises! Promises!
• message interpolation feels a bit wonky with the msgVars and the msgArgs. msgVars are extra args to pass to msgArs that are then interpolated into the message string.