HTML oninvalid Event Attribute

HTML Web Development Front End Technology

The HTML oninvalid event attribute is triggered when an input field is invalid while submitting the form in an HTML document.

Syntax

Following is the syntax −

<tagname oninvalid=”script”></tagname>

Example

Let us see an example of HTML oninvalid event Attribute −

<!DOCTYPE html>
<html>
<head>
<style>
   body {
      color: #000;
      height: 100vh;
      background: linear-gradient(62deg, #FBAB7E 0%, #F7CE68 100%) no-repeat;
      text-align: center;
      padding: 20px;
   }
   textarea {
      border: 2px solid #fff;
      background: transparent;
      font-size: 1rem;
   }
   ::placeholder {
      color: #000;
      font-size: 1rem;
   }
   .btn {
      background: #db133a;
      border: none;
      height: 2rem;
      border-radius: 2px;
      width: 40%;
      display: block;
      color: #fff;
      outline: none;
      cursor: pointer;
      margin: 1rem auto;
   }
</style>
</head>
<body>
<h1>HTML oninvalid Event Attribute Demo</h1>
<form action="" method="">
<textarea placeholder="Enter your message here" oninvalid="invalidFn()" rows='8' cols="50" required></textarea>
<input type="submit" value="SUBMIT" class="btn">
</form>
<p>Click on SUBMIT button without writing any message</p>
<script>
   function invalidFn() {
      document.querySelector('textarea').style.background = '#db133a6e';
      document.querySelector('textarea').setAttribute('placeholder', 'Please enter a message');
   }
</script>
</body>
</html>