Question

I am developing one sharepoint webpart, in this i have 2 date time control, one is for From date and another is for To date, And i wrote one javascript function to validate the date entered by the user. If the To date is less than the from Date, it will alerts. and i added this JS function to the button click as a attribute. But this function is not executing while i am clicking.

i am adding my code with this:

  void Registerscript()
    {
        string jc = @"<script> function DateMsg()
             {{ 

                var Fromdate = document.getElementById('{0}').value;
                var Todate = document.getElementById('{1}').value;

                 if(Fromdate != '' && Todate != '')
                {{             
                if(Date.parse(Fromdate) > Date.parse(Todate))
                  alert('From Date should be earlier than To Date.');
                }}

             }}</script> ";
        jc = string.Format(jc, dtFromdate.ClientID + "_dtFromdateDate", dtTodate.ClientID + "_dtTodateDate");
        this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "Alert", jc);
    }

I called this function in Createchildcontrol method of the webpart..

And i added this code on OnLoad event of the webpart

btnView.Attributes.Add("onclick", "DateMsg();");

Please help me for resoving this issue…

FYI: This btnView(Button control) is dynamically created at runtime..

Thanks in advance…

Answer 1

I would go in different way, allowing easier debug.

Have the function in the .aspx file:

<script type="text/javascript">
function DateMsg() {
    if (typeof _fromDateTextboxID != "undefined") {
        var oFromDateInput = document.getElementById(_fromDateTextboxID);
        var oToDateInput = document.getElementById(_toDateTextboxID);

        if (!oFromDateInput) {
            alert("element with ID of " + _fromDateTextboxID + " does not exist");
            return;
        }

        if (!oToDateInput) {
            alert("element with ID of " + _toDateTextboxID + " does not exist");
            return;
        }

        var strFromdate = oFromDateInput.value;
        var strTodate = oToDateInput.value;
        if(strFromdate.length == 0 || strTodate.length == 0) {
            alert("one or more values empty");
            return;
        }

        var dtFromDate = Date.parse(strFromdate);
        var dtToDate = Date.parse(Todate);
        if(dtFromDate > dtToDate) {
            alert('From Date should be earlier than To Date.');
        }

    }
    else {
        alert("ID not initialized");
    }
}
</script>

And output only the ID from the code behind:

string jc = string.Format("var _fromDateTextboxID = \"{0}\"; var _toDateTextboxID = \"{1}\"; ", dtFromdate.ClientID + "_dtFromdateDate", dtTodate.ClientID + "_dtTodateDate");
this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "Alert", jc, true);

Leave the button onclick unchanged, and now you might see what’s wrong – keep us updated.