Changing TargetControl on the client

[Telerik Admin]

A rather popular scenario when using the RadToolTip is to use a single instance on the page and utilize the onmouseover event of the  targeted elements to set a new target for the tooltip via JavaScript and show it. Generally the better approach would be to use a RadToolTip for each control or a RadToolTipManager to load content on demand, yet using a single instance reduces the markup on the page, so it is sometimes used.

When you change a RadToolTip's TargetControl (or TargetControlID) then call its show() method since Q3 2011 you need to do so with a small timeout, e.g.:

<input type="text" onmouseover="showToolTipNewTarget(this);" />

<script type="text/javascript">
    function showToolTipNewTarget(newTarget)
    {
        var radTooltip1 = $find("RadToolTip1");
        radTooltip1.set_targetControl(newTarget);
        setTimeout(function () {
            radTooltip1.show();
        }, 20);
    }
</script>

If you do not use this timeout the necessary calculations cannot be performed and usually the tooltip will be shown next to the previous target.