HTMLInputElement: setCustomValidity() method
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
TheHTMLInputElement.setCustomValidity() method sets a custom validity message for the element.
Syntax
setCustomValidity(message)Parameters
messageThe 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 errormessages depending on whether the value is missing, too low, or too high. Notethat the message will not be displayed immediately. Attempting to submit theform will display the message, or you can call thereportValidity() methodon the element.
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("That's 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 theerror message is not empty, the form will not pass validation and will not besubmitted.
Specifications
| Specification |
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| HTML # dom-cva-setcustomvalidity |