Question

I’m working on asp.net page wich contain a Multiview control and some wizard steps.
I’ve got ten couple of textboxes named like TextboxA[i] and TextBoxB[i] and a counter. Foreach couple of not empty textboxes I want my counter++.

On server side I would be able to write in TextboxA[i] and TextboxB[i] onTextChange event something like

if(String.IsNullOrWhiteSpace(TextboxA[i]))
    counter++;

Not so good…
I’ve to increment counter on client side using javascript but – if I have – I don’t know how. Please, can anyone help me?

Answer 1

Client side code:

<script type="text/javascript">
var counter = 0;

function increaseCounter(textAID, textBID)
{
    var textA = document.getElementById(textAID);
    var textB = document.getElementById(textBID);
    if (isNullOrWhitespace(textA.value) && isNullOrWhitespace(textB.value))
        counter++;
}

function isNullOrWhitespace( input ) {

    if (input == null) return true;

    return input.replace(/\s/g, '').length < 1;
}
</script>

Code for isNullOrWhitespace taken from https://stackoverflow.com/a/5559461/1495902.

Server side code:

for (int i = 0; i < TextboxA.Count() ; i++)
{
    var script = "increaseCounter(" + TextboxA[i].ClientID + "," + TextboxB[i].ClientID + ")";
    TextboxA[i].Attributes.Add("onchange", script);
    TextboxB[i].Attributes.Add("onchange", script);
}