Pass Data to the Web Service
This article explains how to pass information to the web service the LiveTile uses to get its contents. This data is a string that can be used to identify the request and prepare the response accordingly.
The parameter that is passed to the web service is the Value property of the LiveTile. The sections below explain how to access it in the different types of services that are supported. At the end of the article you can also see how you can change the value dynamically just before the request is performed.
Passing Data to a Web Service
The Value property of the LiveTile is passed to the web service method (Example 1) and it can be obtained by casting theobject received as an argument, to a Dictionary with a string key called Value.
Example 1: How to access the arguments a web service receives.
[WebMethod]
public string GetServerData(object context)
{
string value = "defaultValue";
if (context != null)
{
IDictionary<string, object> contextDictionary = (IDictionary<string, object>)context;
value = ((string)contextDictionary["Value"]);
}
//use the information here to return concrete information
return value;
}
<WebMethod> _
Public Function GetServerData(context As Object) As String
Dim value As String = "defaultValue"
If context IsNot Nothing Then
Dim contextDictionary As IDictionary(Of String, Object) = DirectCast(context, IDictionary(Of String, Object))
value = DirectCast(contextDictionary("Value"), String)
End If
'use the information here to return concrete information
Return value
End Function
This example returns the value that the LiveTile passes, or uses some default setting. By using such logic, you can have several LiveTiles that request similar data use one service and distinguish them by their values. Example 2 shows two simple LiveTiles that use the same method and will get different data. They use the simplest template possible. You can find more information on using complex objects in the Loading Data help article.
Example 2: Two simple LiveTiles that request data from the same web service with different arguments.
<telerik:RadLiveTile runat="server" ID="RadLiveTile1" Value="first">
<ClientTemplate>
Data returned from the server: <br />
#=data#
</ClientTemplate>
<WebServiceSettings Method="GetServerData" Path="TileWebService.asmx" />
</telerik:RadLiveTile>
<telerik:RadLiveTile runat="server" ID="RadLiveTile2" Value="second">
<ClientTemplate>
Data returned from the server: <br />
#=data#
</ClientTemplate>
<WebServiceSettings Method="GetServerData" Path="TileWebService.asmx" />
</telerik:RadLiveTile>
Passing Data to a WCF Service
The Value property of the LiveTile is passed to a WCF service wrapped in an object and to access it, you need a strongly-typed object as the argument of the method. Examples 3-6 demonstrate a simple LiveTile that requests data:
Example 3: A sample WCF class and method that will return information.
[ServiceContract(Namespace = "")]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class TileService
{
[OperationContract]
[WebInvoke(Method = "POST", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)]
public CustomObject GetServerData(RadLiveTileContext context)
{
string value = "Janet";//a default value
if (context != null)
{
value = context.Value;
}
//use the information here to return concrete information
CustomObject item = CustomObject.GetDataItems().Where(p => p.Name.Contains(value)).First();
return item;
}
}
<ServiceContract([Namespace]:="")> _
<AspNetCompatibilityRequirements(RequirementsMode:=AspNetCompatibilityRequirementsMode.Allowed)> _
Public Class TileService
<OperationContract()> _
<WebInvoke(Method:="POST", RequestFormat:=WebMessageFormat.Json, ResponseFormat:=WebMessageFormat.Json)> _
Public Function GetServerData(context As RadLiveTileContext) As CustomObject
Dim value As String = "Janet" 'a default value
If context IsNot Nothing Then
value = context.Value
End If
'use the information here to return concrete information
Dim item As CustomObject = CustomObject.GetDataItems().Where(Function(p) p.Name.Contains(value)).First()
Return item
End Function
End Class
Example 4: The class that is needed to access the value from the LiveTile in a WCF service.
[Serializable]
public class RadLiveTileContext : Dictionary<string, object>
{
public string Value
{
get { return (string)this["Value"]; }
set { this["Value"] = value; }
}
}
<Serializable()> _
Public Class RadLiveTileContext
Inherits Dictionary(Of String, Object)
Public Property Value() As String
Get
Return DirectCast(Me("Value"), String)
End Get
Set(value As String)
Me("Value") = value
End Set
End Property
End Class
Example 5: A sample class that will provide data to the service.
[DataContract]
public class CustomObject
{
[DataMember]
public string Name { get; set; }
[DataMember]
public string Description { get; set; }
public CustomObject(string name, string description)
{
Name = name;
Description = description;
}
public static List<CustomObject> GetDataItems()
{
List<CustomObject> itemsData = new List<CustomObject>();
itemsData.Add(new CustomObject("Janet Leverling", "Sales Representative"));
itemsData.Add(new CustomObject("Margaret Peacock", "Sales Associate"));
itemsData.Add(new CustomObject("Steven Buchanan", "Sales Manager"));
return itemsData;
}
}
<DataContract()> _
Public Class CustomObject
<DataMember()> _
Public Property Name() As String
Get
Return m_Name
End Get
Set(value As String)
m_Name = Value
End Set
End Property
Private m_Name As String
<DataMember()> _
Public Property Description() As String
Get
Return m_Description
End Get
Set(value As String)
m_Description = Value
End Set
End Property
Private m_Description As String
Public Sub New(name**1 As String, description**2 As String)
Name = name**1
Description = description**2
End Sub
Public Shared Function GetDataItems() As List(Of CustomObject)
Dim itemsData As New List(Of CustomObject)()
itemsData.Add(New CustomObject("Janet Leverling", "Sales Representative"))
itemsData.Add(New CustomObject("Margaret Peacock", "Sales Associate"))
itemsData.Add(New CustomObject("Steven Buchanan", "Sales Manager"))
Return itemsData
End Function
End Class
Example 6: Two simple LiveTiles that request information for different people from the class in Example 5.
<telerik:RadLiveTile runat="server" ID="RadLiveTile1" Value="Margaret">
<ClientTemplate>
Data returned from the server: <br />
#=Name# is a #=Description#
</ClientTemplate>
<WebServiceSettings Method="GetServerData" Path="TileService.svc" />
</telerik:RadLiveTile>
<telerik:RadLiveTile runat="server" ID="RadLiveTile2" Value="Steven">
<ClientTemplate>
Data returned from the server: <br />
#=Name# is a #=Description#
</ClientTemplate>
<WebServiceSettings Method="GetServerData" Path="TileService.svc" />
</telerik:RadLiveTile>
Passing Data to Page Methods
Data is not passed to page methods and the LiveTile cannot be identified uniquely. Thus, if different data is needed, different methods will need to be defined and configured in the tiles.
Passing Data to an ODataDataSource Control
While a LiveTile can use an ODataDataSource control as its data source, in this case, the data that is returned is controlled by the data source controland it should be configured to return the expected information.
You can see an example in the Loading Data help article, in the Loading Data From ODataDataSource section. It shows how the data source itself can be filtered in its own event (Example 7).
Example 7: Filtering an ODataDataSource control.
<telerik:RadLiveTile ID="RadLiveTile3" runat="server"
ODataDataSourceID="RadODataDataSource1" DataModelID="Employee">
<ClientTemplate>
<strong>Loaded from ODataDataSource: </strong><br />
#= FirstName # #= LastName # <br /> #= Title #
</ClientTemplate>
</telerik:RadLiveTile>
<telerik:RadODataDataSource runat="server" ID="RadODataDataSource1">
<Transport>
<Read Url="http://demos.kendoui.com/service/Northwind.svc/" />
</Transport>
<Schema>
<telerik:DataModel ModelID="Employee" Set="Employees">
<telerik:DataModelField FieldName="LastName" />
<telerik:DataModelField FieldName="FirstName" />
<telerik:DataModelField FieldName="Title" />
</telerik:DataModel>
</Schema>
<ClientEvents Requesting="Requesting" />
</telerik:RadODataDataSource>
<script type="text/javascript">
function Requesting(sender, args) {
args.set_filterExpressions({
field: "Title",
operator: "eq",
value: "Sales Manager"
});
}
</script>
Another option is to change the filter in the OnClientDataLoading event, because the event arguments expose the data source arguments. Essentially, the logic is the same, but you can apply filters per LiveTile (e.g., by using different OnClientDataLoading event handlers, see Example 8) and use the same ODataDataSource control.
Example 8: Filtering the data source in the OnClientDataLoading event.
<script type="text/javascript">
function OnClientDataLoading(sender, args)
{
args.get_value().filter.filters.push({
field: "CategoryID",
operator: "eq",
value: Math.floor(Math.random() * 9)
});
}
</script>
Change the Value for the Given Request
Just before the request is initiated, the OnClientDataLoading event is fired.You can use it to change the value that will be passed in the request. In Example 7 you saw how it can be used to filter an ODataDataSource control. Example 9 demonstrates how you can change the value passed to web services and WCF services. You need to emulate the JSON object that is sentvia the set_value() method the event arguments object exposes.
Example 9: Changing the value passed to a WCF/Web service.
<script type="text/javascript">
function OnClientDataLoading(sender, args)
{
//Change the value of the "Value" key
//in this example, the new string that is set is "myNewValue"
args.set_value({
"Key": "Value",
"Value": "myNewValue"
});
}
</script>