Call Javascript onchange event by programmatically

Question

the problem I'm facing is this:

• I have a textbox for a date range along side a calendar control.
• When the user selects a date from the calendar, it fills that date into the textbox
• When this happens I want to fire a javascript function, however, the 'onchange' event doesn't seem to happen.

I'd ideally like to be able to add the event as an attribute to the textbox, something like:

txtCreateDate.Attributes.Add("onchange", string.Format("JSfunction({0},'{1}');", arg1, arg2));

more info: The date is entered into the textbox in c#. The calendar control has an eventhandler on the page. When a date is selected, the eventhandler puts the date into the textbox. I have tried setting the focus to the textbox at this point, then putting an onBlur attribute on the textbox, but the textbox never seems to get focus.

I suppose I could directly call the javascript function at this point doing ClientScript.RegisterClientScriptBlock or something like that, but that seems sloppy and never works like I want it to.

Answer 1

The "onchange" is only fired when the attribute is programmatically changed or when the user makes a change and then focuses away from the field.

Have you looked at using YUI's calendar object? I've coded up a solution that puts the yui calendar inside a yui panel and hides the panel until an associated image is clicked. I'm able to see changes from either.

http://developer.yahoo.com/yui/examples/calendar/formtxt.html

Answer 2

This is an old question, and I'm not sure if it will help, but I've been able to programatically fire an event using:

if (document.createEvent && ctrl.dispatchEvent) {
    var evt = document.createEvent("HTMLEvents");
    evt.initEvent("change", true, true);
    ctrl.dispatchEvent(evt); // for DOM-compliant browsers
} else if (ctrl.fireEvent) {
    ctrl.fireEvent("onchange"); // for IE
}