Validations is an addition to Mootools Class.Extras, providing the ability to run any number of validations on a class.

Validations is inspired by Mootools own Events and by caolan's async.js.

The most basic usage is to create a group of validations to be run when asked. The validate method takes a callback, with err as the first argument, in the async.js style.

var ValidatableClass = new Class({
    Implements: Validations
});

var validateMe = new ValidatableClass();

var myGreatValidation = function (callback) {
    if (1===2) {
        callback("Something is wrong here.");
    } else {
        callback();
    }
};

validateMe.addValidation(myGreatValidation);

validateMe.validate(function (err) {
    if (err) {
        console.log(err);
    } else {
        console.log("Everything is so great!");
    }
});

Add a new validation function, to be executed when validate is called.

Validation functions should take a callback argument, to be called upon deciding whether the validation has passed or failed.

The callback will accept an err as the first argument when the validation fails. When the validation passes, ensure that the first argument passed to the callback is falsey (null, false, etc).

myClass.addValidation(fn);

1. fn - (function) The validation function to execute.

• (object) This Class instance.

var myValidation = function (callback) {
    if (validateMe.hasNeededProperty()) {
        callback(null);
    } else {
        callback("Does not have Needed Property.");
    }
};

validateMe.addValidation(myValidation);

---

Add an array of validation functions to be executed when validate is called.

myClass.addValidations(arr);

1. arr - (array) An array of validation functions to execute.

• (object) This Class instance.

var myValidation = function (callback) {
    if (validateMe.hasNeededProperty()) {
        callback(null);
    } else {
        callback("Does not have Needed Property.");
    }
};

var myOtherValidation = function (callback) {
    if (validateMe.hasOtherNeededProperty()) {
        callback(null);
    } else {
        callback("Does not have Needed Property.");
    }
};

validateMe.addValidations([myValidation, myOtherValidation]);

---

Remove a validation function from being executed when validate is called.

myClass.removeValidation(fn);

1. fn - (function) The validation function to remove.

• (object) This Class instance.

validateMe.removeValidation(myOtherValidation);

---

Remove all validation functions from being executed when validate is called.

myClass.removeValidations();

• (object) This Class instance.

validateMe.removeValidations();

---

Each validation function is called with a callback for when they have all finished. If any validation function passes an error to this callback, the main callback is immediately called with the error.

myClass.validate(callback, method);

1. callback - (function) Callback function to be executed when all of the validation functions complete, or when any one of them passes an error.
2. method - (string, optional) async method to use to run validations. Currently limited to parallel, series, and waterfall. Defaults to parallel, if not passed.

• (object) This Class instance.

validateMe.validate(function (err) {
    if (err) {
        console.log(err);
    } else {
        console.log("Everything is so great!");
    }
}, 'series');