ElementInternals: validity property - Web APIs | MDN (original) (raw)

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The validity read-only property of the ElementInternals interface returns a ValidityState object which represents the different validity states the element can be in, with respect to constraint validation.

Value

Exceptions

NotSupportedError DOMException

Thrown if the element does not have its formAssociated property set to true.

Examples

The following example shows a custom checkbox component with formAssociated set to true, the value of validity.valid is logged to the console.

class CustomCheckbox extends HTMLElement {
  static formAssociated = true;

  constructor() {
    super();
    this.internals_ = this.attachInternals();
  }

  // …
}

window.customElements.define("custom-checkbox", CustomCheckbox);

let element = document.getElementById("custom-checkbox");
console.log(element.internals_.validity.valid);

Specifications

Browser compatibility