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Function Description
Fz.Validation.registerValidator() Registers a new validator.

Register a validator


Fz.Validation.registerValidator(name, callback)




  • name: name of the validator, must be unique. If the validator is a JavaScript implementation of a PHP validator, then name must be the name of the validator PHP class, for instance Romm\Formz\Validation\Validator\RequiredValidator.
  • callback: the function which is called when the validator is used to know if a value is valid.


Like their PHP implementation, validators allow JavaScript to know if a value is valid or not. The goal of JavaScript validators is to instantly give to the user the indication on the validity of the given value for a field, without having to wait for a server-side validation.

Most of the time, a JavaScript validator is a JavaScript conversion of the PHP validator algorithm.

The validator logic will be inside callback, which follows these rules:

  1. It has three arguments:
    • value: the value which must be validated.
    • callback: the function which must be called when the validator finishes its validation work.
    • states: an object containing the properties below:
      • result: the result instance which is used to add errors if the validation does not pass.
      • configuration: the configuration array of the validator.
      • data: a list of properties which may be used during the validation.
      • validatorName: name of the used validator.
  2. The validator must in every case call callback();, because this is the way FormZ detects the end of the validation process. Not calling it may break the entire FormZ process.
  3. To add an error, you must use the result instance in states['result'], see the example below.

Validator example:

    function (value, callback, states) {
        if (value !== 'foo') {
            states['result'].addError('default', states['configuration']['messages']['default']);