HTMLButtonElement: reportValidity() method

The reportValidity() method of the {{domxref("HTMLButtonElement")}} interface performs the same validity checking steps as the {{domxref("HTMLButtonElement.checkValidity", "checkValidity()")}} method. In addition, if the {{domxref("HTMLElement/invalid_event", "invalid")}} event is not canceled, the browser displays the problem to the user.

Syntax

js-nolint

reportValidity()

Parameters

None.

Return value

Returns true if the element's value has no validity problems; otherwise, returns false.

Examples

This far fetched example demonstrates how a button can be made invalid.

HTML

We create a form that only contains a few buttons:

html

<form action="#" id="form" method="post">
  <p>
    <input type="submit" value="Submit" />
    <button id="example" type="submit" value="fixed">THIS BUTTON</button>
  </p>
  <p>
    <button type="button" id="report">reportValidity()</button>
  </p>
</form>

<p id="log"></p>

CSS

We add a bit of CSS, including :valid and :invalid styles for our button:

css

input[type="submit"],
button {
  background-color: #3333aa;
  border: none;
  font-size: 1.3rem;
  padding: 5px 10px;
  color: white;
}
button:invalid {
  background-color: #aa3333;
}
button:valid {
  background-color: #33aa33;
}

JavaScript

We include a function to toggle the value, content, and validation message of the example button:

const reportButton = document.querySelector("#report");
const exampleButton = document.querySelector("#example");
const output = document.querySelector("#log");

reportButton.addEventListener("click", () => {
  const reportVal = exampleButton.reportValidity();
  output.innerHTML = `reportValidity returned: ${reportVal} 
 custom error: ${exampleButton.validationMessage}`;
});

exampleButton.addEventListener("invalid", () => {
  console.log("Invalid event fired on exampleButton");
});

exampleButton.addEventListener("click", (e) => {
  e.preventDefault();
  if (exampleButton.value === "error") {
    breakOrFixButton("fixed");
  } else {
    breakOrFixButton("error");
  }
  output.innerHTML = `validation message: ${exampleButton.validationMessage} 
 custom error: ${exampleButton.validationMessage}`;
});

function breakOrFixButton() {
  const state = toggleButton();
  if (state === "error") {
    exampleButton.setCustomValidity("This is a custom error message");
  } else {
    exampleButton.setCustomValidity("");
  }
}

function toggleButton() {
  if (exampleButton.value === "error") {
    exampleButton.value = "fixed";
    exampleButton.innerHTML = "No error";
  } else {
    exampleButton.value = "error";
    exampleButton.innerHTML = "Custom error";
  }
  return exampleButton.value;
}

Results

The button is by default valid. Activate "THIS BUTTON" to change the value, content, and add a custom error message. Activating the "reportValidity()" button checks the validity of the button, reporting the custom error message to the user and throwing an invalid event if the button does not pass constraint validation due to the message.