asked on

webmethod return value in asp.net

In the following code my aim is to get a value from a web method and use it for further operations inside a javascript. However I cannot do so because when I cannot somehow store the returned value in a hidden filed.

function webMethodCaller( ids){
         PageMethods.FormatName(ids, 
      onFormatNameSuccess, 
      onFormatNameFail, 
      onFormatNameTimeout); 
      
            
        result=document.getElementById("HiddenField1").value;
 
// i want to do something else based on result after this
}



 function onFormatNameSuccess(response)
{
      debugger;
                  
      var res="";
      
      for(var i=0,il=response.length; i<il;i++){
      res+=response[i];
      }
      
      document.getElementById("HiddenField1").value = res;

}

function onFormatNameFail (exception, ctx, methodName) 
{ 
      alert("Method:"+ methodName +"\n"+ 
            exception.get_exceptionType() +"\n"+
            exception._message); 
}
function onFormatNameTimeout () 
{ 
      alert("Timeout"); 
}








///////////////////////////////////////////////

   <form id="form1" runat="server">
        <asp:HiddenField ID="hdnReturnValue" runat="server" Value="xx" />
        <asp:HiddenField ID="HiddenField1" runat="server" />
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        <input type="hidden" id="hiddnvalue" runat="server" value="" />
        <asp:ScriptManager ID="yourScriptManager" runat="server" EnablePageMethods="true">
        </asp:ScriptManager>
    </form>


the web method is the folloiwng
///////////////////////////////////////

 [WebMethod, ScriptMethod]
        static public List<String> FormatName(string featureIds)
        {
           

            string[] rawdata = featureIds.Split(new char[] { ',' });

            List<String> strings = new List<String>();
            for (int i = 0; i < rawdata.Length; i++)
            {
                strings.Add(rawdata[i]);
            }
            // strings.Add(FirstName);
            // strings.Add(LastName);*/

            //Session["result"] = strings;
            //   hdnReturnValue.value = strings;
          //  HiddenField1.Value = featureIds;
           // hiddnvalue.Value = featureIds;
            return strings;
            // LastName + ", " + FirstName;

        }

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leakim971

Why don't wait the call of onFormatNameSuccess and do what you want ?

AbebeDemeke

ASKER

leakim971: the thing is , is there any other way to get the value returned from the webmethod than storing somewhere inside the onFormatNameSuccess ?

leakim971

What about :

function webMethodCaller( ids){
  PageMethods.FormatName(ids, onFormatNameSuccess, onFormatNameFail, nFormatNameTimeout);
}

function part2(result) {
//result=document.getElementById("HiddenField1").value;

// i want to do something else based on result after this

}

function onFormatNameSuccess(response) {
  result = document.getElementById("HiddenField1").value;
  var res="";
  for(var i=0,il=response.length; i<il;i++){
    res+=response[i];
  }
  part2(res);
}

Open in new window

AbebeDemeke

ASKER

leakim971: the issue is I want the value stored somewhere. Again I tried to store in your part2 method as :
function part2(result) {
document.getElementById("HiddenField1").value=result;

// i want to do something else based on result after this

}

function onFormatNameSuccess(response) {
result = document.getElementById("HiddenField1").value;
var res="";
for(var i=0,il=response.length; i<il;i++){
res+=response[i];
}
part2(res);

}

but still the value is not stored in the hidden variable

leakim971

set two alert and give me news :

function part2(result) {
alert("ok1");
document.getElementById("HiddenField1").value=result;
// i want to do something else based on result after this
alert("ok2");
}

AbebeDemeke

ASKER

leakim971: both ok1 and ok2 are displayed

leakim971

And what about :

function part2(result) {
alert(result);
document.getElementById("HiddenField1").value=result;
// i want to do something else based on result after this
alert(document.getElementById("HiddenField1").value);
}

AbebeDemeke

ASKER

there seems to be a mess in here . the alert displays the value in this function but when i try to do it outside of this function . lets say inside the function that calls this the webmethod then it displays empty string

leakim971

strange... I get "test" in alert with the following :

<script language="javascript" type="text/javascript">

    function pageLoad(sender, arg) {
        webMethodCaller("test");
    }

    function webMethodCaller(ids) {
        PageMethods.FormatName(ids, onFormatNameSuccess, onFormatNameFail, onFormatNameTimeout);
    }

    function part2(result) {
        document.getElementById("<%= HiddenField1.ClientID %>").value = result;
    }

    function onFormatNameSuccess(response) {
        result = document.getElementById("<%= HiddenField1.ClientID %>").value;
        var res = "";
        for (var i = 0, il = response.length; i < il; i++) {
            res += response[i];
        }
        part2(res);
        alert(document.getElementById("<%= HiddenField1.ClientID %>").value);
    }

    function onFormatNameFail(exception, ctx, methodName) {
        alert("Method:" + methodName + "\n" + exception.get_exceptionType() + "\n" + exception._message);
    }

    function onFormatNameTimeout() {
        alert("Timeout");
    }

</script>

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AbebeDemeke

ASKER

leakim971: yes that is my question . if u do alert inside onFormatNameSuccess after calling part2 or inside part2 itself things seems fine but if you do alert inside the webMethodCaller like :

function webMethodCaller(ids) {
PageMethods.FormatName(ids, onFormatNameSuccess, onFormatNameFail, onFormatNameTimeout);
alert(document.getElementById("<%= HiddenField1.ClientID %>").value);
}

then you wont get anything. that is my question

leakim971

When using this :

function webMethodCaller(ids) {
PageMethods.FormatName(ids, onFormatNameSuccess, onFormatNameFail, onFormatNameTimeout);
alert(document.getElementById("<%= HiddenField1.ClientID %>").value);
}

The alert is called immediately after PageMethods.FormatName. The ajax call is not ended and the value (HiddenField1) you try to read not updated.
That's why you must wait for the end of the ajax call before trying to do something relative with its final job (which is update the HiddenField1)

leakim971

check this : https://www.experts-exchange.com/questions/26348289/Help-expanding-JavaScript-function-for-use-with-JSON.html?cid=748&anchorAnswerId=33265044#a33265044

If you want to do a synchrone call to be able to get value of the HiddenField just after the ajax call (PageMethod) IN THE SAME FUNCTION, forget PageMethod and use :
http://kpumuk.info/asp-net/synchronous-page-method-call-in-asp-net-ajax-library/

ASKER CERTIFIED SOLUTION

leakim971

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leakim971

Thanks for the points!