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Missing EmptyMessage and wrong css class after requestItems

10 Answers 210 Views

ComboBox

This is a migrated thread and some comments may be shown as answers.

Tim asked on 07 Apr 2009, 04:51 PM

I have a RadComboBox that is not databound at the server but is set up with WebServiceSettings to allow it to be loaded from the client. I am using this to load different items depending on the state of other controls on the page, but do not want load on demand functionality, instead I am calling requestItems() from client-side code when I require the items in the list to change:

    
            <telerik:RadComboBox ID="cboCustomer" runat="server" EmptyMessage="Select a customer" MarkFirstMatch="true" OnClientItemsRequesting="cboCustomer_ItemsRequesting"> 
        
                <WebServiceSettings Path="Services/ComboData.asmx" Method="GetCustomers" /> 
        
            </telerik:RadComboBox> 
        
            <script type="text/javascript"> 
        
                function cboCustomer_ItemsRequesting(sender, eventArgs) { 
        
                    var context = eventArgs.get_context(); 
        
                    context["SelectBy"] = getSelectBy(); 
        
                } 
        
            </script>

When I then call $find("<%=cboCustomer.ClientID %>").requestItems("", false) the list is populated correctly from my web service, but the empty message disappears. if I select an item from the list it is displayed with the rcbEmptyMessage css class applied (sometimes multiple times) even though an item is selected. If I delete the text from the combobox the empty message doesn't reappear.

10 Answers, 1 is accepted

answered on 15 Apr 2009, 11:21 AM

Hello Tim,

This is a known problem and until we fix it I suggest that you use the following workaround:

Subscribe to the OnClientSelectedIndexChanged event and put this code in the handler:

    
            function OnClientSelectedIndexChangedHandler(sender, e) 
        
            { 
        
                var inputElement = sender.get_inputDomElement(); 
        
                inputElement.className = inputElement.className.replace("rcbEmptyMessage", ""); 
        
            }

Best wishes,
Veselin Vasilev
the Telerik team

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answered on 28 Apr 2009, 01:57 PM

Page:

    
            <head runat="server"> 
        
                <telerik:RadCodeBlock runat="server"> 
        
                    <script type="text/javascript"> 
        
                        function refreshNumbersCombo() { 
        
                            $find("<%=cboNumbers.ClientID %>").requestItems("", false); 
        
                        } 
        
                        function cboNumbers_ItemsRequesting(sender, eventArgs) { 
        
                            sender.clearSelection(); 
        
                            var context = eventArgs.get_context(); 
        
                            context["Count"] = parseInt($get("txtCount").value); 
        
                        } 
        
                        function cboNumbers_SelectedIndexChanged(sender, eventArgs) { 
        
                            var inputElement = sender.get_inputDomElement(); 
        
                            inputElementinputElement.className = inputElement.className.replace(/rcbEmptyMessage/g, ""); 
        
                        } 
        
                    </script> 
        
                </telerik:RadCodeBlock> 
        
            </head> 
        
            <body> 
        
                <form id="form1" runat="server"> 
        
                    <asp:ScriptManager ID="scriptManager" runat="server"></asp:ScriptManager> 
        
                    <div> 
        
                        <input id="txtCount" type="text" value="1" style="width: 2em;" /> 
        
                        <input id="btnSetCount" type="button" value="Set Count" onclick="refreshNumbersCombo();" /> 
        
                    </div> 
        
                    <telerik:RadComboBox ID="cboNumbers" runat="server" MarkFirstMatch="true" EmptyMessage="- Pick a number -" OnClientItemsRequesting="cboNumbers_ItemsRequesting" OnClientSelectedIndexChanged="cboNumbers_SelectedIndexChanged"> 
        
                        <WebServiceSettings Path="ComboData.asmx" Method="GetNumbers" /> 
        
                    </telerik:RadComboBox> 
        
                </form> 
        
            </body>

Web service:

    
                [ScriptService] 
        
                public class ComboData : System.Web.Services.WebService 
        
                { 
        
                    [WebMethod] 
        
                    public RadComboBoxItemData[] GetNumbers(RadComboBoxContext context) 
        
                    { 
        
                        int count = (int)context["Count"]; 
        
                        var items = Enumerable.Range(1, count).Select(i => new RadComboBoxItemData() 
        
                            { 
        
                                Value = i.ToString(), 
        
                                Text = i.ToString() 
        
                            }); 
        
                        return items.ToArray(); 
        
                    } 
        
                }

Type a number in the text box and click the button to cause the combo box to be repopulated using the web method. The emptymessage instantly disappears from the combo box and won't reappear, even if you select an item in the combo box and then remove it again. Hope this helps resolve it...

Accepted