GridPanel Renderer doesn' work

Code:

---

<script type="text/javascript">
    var renderFileLink = function (value, meta, record) {
        var a = Ext.net.DirectMethods.<%=ClientID%>.GetFilePath(record.data.Source, record.data.FileName, record.data.TypeId);
        alert(a);
        return a;
    }
   
</script>

<!--some code  ------>
<ColumnModel runat="server">
        <Columns>
            <ext:Column Header="Описание файла" DataIndex="Description" Width="250">
                <Renderer Fn="renderFileLink" />
            </ext:Column>
        </Columns>
    </ColumnModel>

[DirectMethod]
public string GetFilePath(Guid sourceId, string fileName, int fileType) {
      var a = sourceId.ToString() + fileName + fileType.ToString();
      return a;
}

---

The function renderFileLink always returns "undefined", but the method "GetFilePath" returns the other (properly) data. But I want to display the data which has been received from the method "GetFilePath". How can I do it?

DirectMethods are async action (because it uses XmlHttpRequest which is async by default)
It means that you have to use callbacks (success/failure) to retrieve the result
You cannot use direct methods in the renderer because renderer requires immediate answer

If you need to show some server side data then bind it as RecordField in the store

It's good, very good!