HTMLObjectElement.setCustomValidity()

The setCustomValidity() method of the HTMLObjectElement interface sets a custom validity message for the element.

Syntax

setCustomValidity(errorMessage)

Parameters

errorMessage

The message to use for validity errors.

Return value

None (undefined).

Exceptions

None.

Examples

In this example, we pass the ID of an input element, and set different error messages depending on whether the value is missing, too low or too high. Additionally you must call the reportValidity method on the same element or nothing will happen. 

function validate(inputID) {
  const input = document.getElementById(inputID);
  const validityState = input.validity;

  if (validityState.valueMissing) {
    input.setCustomValidity("You gotta fill this out, yo!");
  } else if (validityState.rangeUnderflow) {
    input.setCustomValidity("We need a higher number!");
  } else if (validityState.rangeOverflow) {
    input.setCustomValidity("Thats too high!");
  } else {
    input.setCustomValidity("");
  }

  input.reportValidity();
}

It's vital to set the message to an empty string if there are no errors. As long as the error message is not empty, the form will not pass validation and will not be submitted.

Specifications

Specification
HTML Standard
# dom-cva-setcustomvalidity-dev

Browser compatibility

BCD tables only load in the browser

See also