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HTML ononline Attribute

HTML

The HTML ononline attribute is an event handler that triggers a script to execute when the browser's network connection status changes from offline to online.

Definition and Usage


➔ This is the opposite of the onoffline attribute.

➔ It is mainly used in the <body> element or Window object.

➔ Its primary purpose is to improve the user experience, by displaying a message about the network connection or need to adjust their functionality by going back online after the connection is restored.

Syntax
//In HTML
<body ononline="myFunction()"></body>

//In JavaScript
window.addEventListener("online", (event) => {
  alert("You are now online!");
  // Add code to handle online state
});

// Or using the event handler property:
window.ononline = (event) => {
    alert("You are now online!");
};
function myFunction() {
    alert("You are now online!");
}

Example
<!DOCTYPE html>
<html>
<head>
    <title>HTML ononline attribute example</title>
</head>
<body ononline="myFunction()">
    <h1>HTML ononline attribute example</h1>
    <p>Try enabling/disabling your network connection to trigger event.</p>
    <script>
        function myFunction() {
            alert("You are now online!");
        }
    </script>
</body>
</html>

Applies to

This attribute can be used on the following element.

Attribute Element
ononline <body>