index.html

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Colorize</title>
    <script src="colorize.js" ></script>
    <script src="gradiantor.js" ></script>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <div id="gradiantor"></div>
    <script>       
        document.getElementById( "gradiantor" ).addEventListener( "click", function (e) {
            e.stopPropagation();
            /* 
            { 
                "id" : null, 
                "container" : "the container for widget(required)", 
                "value" : "linear-gradient(45deg,rgb(55, 192, 176) 0%,rgb(245, 155, 146) 100%)" 
            } 
            */
            var data = {
                "id" : e.currentTarget.id,
                "container" : document.getElementById( "gradiantor" ),
                "value" : null
            }
            var gradiantor = new Gn8Gradiantor( data );
            gradiantor.init().then( success => {
                document.getElementById( "gradiantor" ).style.backgroundImage = success;
                console.log( success );
            },error => {} );
        } );
    </script>
</body>
</html>