Custom Validation Rule

how to create a costume rule validation, to fit your project requirement.

.onError() allows for custom error handling tailored to specific validation scenarios. This method accepts an object of type ValidatorFnConfig<FieldType, ObjectType>, which provides a structured way to define validation functions and associated error messages.

• error: This field specifies the validation function. It accepts parameters:

  • value: The current value of the field being validated.
  • container (optional): The object containing the field being validated.

  The function returns true if validation fails (i.e., an error condition is detected), and false otherwise.

• message: Optionally, you can specify an error message associated with the validation function. This can be a string or a function returning a string, allowing for dynamic error messages based on validation outcomes.

v.string().onError({
  error: (value: string) => {
      return true //error
  },
  message: "message to be displayed"
})