How to change knob value dynamically in jquery..?

I have applied a jquery knob with readonly feature as follows :

<style>
.test{
    background: #292929;
    margin:50px;
}
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="https://raw.github.com/aterrien/jQuery-Knob/master/js/jquery.knob.js"></script>
<body>

<input type="text" value="45%" class="dial"><button id="change">Change</button>
</body>
<script>
$(".dial").knob({
    readOnly: true,
    fgColor: "#00ABC6",
    bgColor: "#666666",
    thickness: 0.2
                });

$(document.body).on('click', 'button#change', function(){
    $("input.dial").val('80%');
    })
</script>

Now when i click on change button it only changes the value of input tag but failed to change the percentage on knob filled area.

Solution

Just trigger an change event on the input after setting the value for it like :

$("input.dial").trigger('change');

Your code will look like :

<style>
.test{
    background: #292929;
    margin:50px;
}
</style>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="https://raw.github.com/aterrien/jQuery-Knob/master/js/jquery.knob.js"></script>
<body>

<input type="text" value="45%" class="dial"><button id="change">Change</button>
</body>
<script>
$(".dial").knob({
    readOnly: true,
    fgColor: "#00ABC6",
    bgColor: "#666666",
    thickness: 0.2
                });

$(document.body).on('click', 'button#change', function(){
    $("input.dial").val('80%');
    $("input.dial").trigger('change');
    })
</script>