HTMLTextAreaElement: setCustomValidity() method

The setCustomValidity() method of the HTMLTextAreaElement interface sets the custom validity message for the <textarea> element. Use the empty string to indicate that the element does not have a custom validity error.

Syntax

setCustomValidity(string)

Parameters

string

The string containing the error message. The empty string removes any custom validity errors.

Return value

None (undefined).

Examples

In this example, if the <textarea>'s doesn't pass constraint validation, we provide custom errors based on the constraint that is failing validation. If the value is valid, we set the custom error to an empty string:

const comment = document.getElementById("comment");
if (comment.validity.valueMissing) {
  comment.setCustomValidity("We can't submit a blank comment!");
} else if (comment.validity.tooShort) {
  comment.setCustomValidity("Tell us more! Your comment is too short.");
} else if (comment.validity.tooLong) {
  comment.setCustomValidity(
    "Loquacious much? Keep it to under 800 characters!",
  );
} else {
  comment.setCustomValidity("");
}

Specifications

Browser compatibility

See also

• <textarea>
• HTMLTextAreaElement
• HTMLTextAreaElement.validity
• HTMLTextAreaElement.checkValidity()
• HTMLTextAreaElement.reportValidity()
• Form validation.
• Learn: Client-side form validation
• Guide: Constraint validation
• CSS :valid and :invalid pseudo-classes