How to: Customize Feeds with the Reflection Provider (WCF Data Services)
WCF Data Services enables you to customize the Atom serialization in a data service response so that properties of an entity may be mapped to unused elements that are defined in the AtomPub protocol. This topic shows how to define mapping attributes for the entity types in a data model that is defined by using the reflection provider. For more information, see Feed Customization (WCF Data Services).
The data model for this example is defined in the topic How to: Create a Data Service Using the Reflection Provider (WCF Data Services)
Example
In the following example, both properties of the Order type are mapped to existing Atom elements. The Product property of the Item type is mapped to a custom feed attribute in a separate namespace.
Imports System
Imports System.Collections.Generic
Imports System.Data.Services
Imports System.Data.Services.Common
Imports System.Linq
Namespace CustomDataService
<EntityPropertyMappingAttribute("Customer", _
SyndicationItemProperty.AuthorName, _
SyndicationTextContentKind.Plaintext, True)> _
<EntityPropertyMapping("OrderId", _
SyndicationItemProperty.Title, _
SyndicationTextContentKind.Plaintext, False)> _
<DataServiceKeyAttribute("OrderId")> _
Public Class Order
Private _orderId As Integer
Private _customer As String
Private _items As IList(Of Item)
Public Property OrderId() As Integer
Get
Return _orderId
End Get
Set(ByVal value As Integer)
_orderId = value
End Set
End Property
Public Property Customer() As String
Get
Return _customer
End Get
Set(ByVal value As String)
_customer = value
End Set
End Property
Public Property Items() As IList(Of Item)
Get
Return _items
End Get
Set(ByVal value As IList(Of Item))
_items = value
End Set
End Property
End Class
<EntityPropertyMappingAttribute("Product", _
SyndicationItemProperty.CategoryTerm, _
true, SyndicationCriteria.CategoryScheme, _
"http://northwindtraders.com/Products")> _
<EntityPropertyMappingAttribute("Url", _
SyndicationItemProperty.LinkHref, false, _
SyndicationCriteria.LinkRel, _
"http://northwindtraders.com/ProductUrl")>
<DataServiceKeyAttribute("Product")> _
Public Class Item
Private _product As String
Private _quantity As Integer
Private _url As String
Public Property Product() As String
Get
Return _product
End Get
Set(ByVal value As String)
_product = value
End Set
End Property
Public Property Quantity() As Integer
Get
Return _quantity
End Get
Set(ByVal value As Integer)
_quantity = value
End Set
End Property
Public Property Url As String
Get
Return _url
End Get
Set(ByVal value As String)
_url = value
End Set
End Property
End Class
Partial Public Class OrderItemData
#Region "Populate Service Data"
Shared _orders As IList(Of Order)
Shared _items As IList(Of Item)
Sub New()
_orders = New Order() { _
New Order() With {.OrderId = 0, .Customer = "Peter Franken", .Items = New List(Of Item)()}, _
New Order() With {.OrderId = 1, .Customer = "Ana Trujillo", .Items = New List(Of Item)()}}
_items = New Item() { _
New Item() With {.Product = "Chai", .Quantity = 10, _
.Url = "http://northwindtraders.com/Teas"}, _
New Item() With {.Product = "Chang", .Quantity = 25, _
.Url = "http://northwindtraders.com/Specialty"}, _
New Item() With {.Product = "Aniseed Syrup", .Quantity = 5, _
.Url = "http://northwindtraders.com/Specialty"}, _
New Item() With {.Product = "Chef Anton's Cajun Seasoning", _
.Quantity = 30, .Url = "http://northwindtraders.com/Spices"}}
_orders(0).Items.Add(_items(0))
_orders(0).Items.Add(_items(1))
_orders(1).Items.Add(_items(2))
_orders(1).Items.Add(_items(3))
End Sub
#End Region
Public ReadOnly Property Orders() As IQueryable(Of Order)
Get
Return _orders.AsQueryable()
End Get
End Property
Public ReadOnly Property Items() As IQueryable(Of Item)
Get
Return _items.AsQueryable()
End Get
End Property
End Class
Public Class OrderItems
Inherits DataService(Of OrderItemData)
' This method is called only once to initialize
' service-wide policies.
Shared Sub InitializeService(ByVal config As DataServiceConfiguration)
config.SetEntitySetAccessRule("Orders", _
EntitySetRights.AllRead _
Or EntitySetRights.AllWrite)
config.SetEntitySetAccessRule("Items", _
EntitySetRights.AllRead _
Or EntitySetRights.AllWrite)
config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V3
End Sub
End Class
End Namespace
using System;
using System.Collections.Generic;
using System.Data.Services;
using System.Data.Services.Common;
using System.Linq;
namespace CustomDataService
{
[EntityPropertyMappingAttribute("Customer",
SyndicationItemProperty.AuthorName,
SyndicationTextContentKind.Plaintext, true)]
[EntityPropertyMapping("OrderId",
SyndicationItemProperty.Title,
SyndicationTextContentKind.Plaintext, false)]
[DataServiceKeyAttribute("OrderId")]
public class Order
{
public int OrderId { get; set; }
public string Customer { get; set; }
public IList<Item> Items { get; set; }
}
[EntityPropertyMappingAttribute("Product",
SyndicationItemProperty.CategoryTerm,
true, SyndicationCriteria.CategoryScheme,
"http://northwindtraders.com/Products")]
[EntityPropertyMappingAttribute("Url",
SyndicationItemProperty.LinkHref, false,
SyndicationCriteria.LinkRel,
"http://northwindtraders.com/ProductUrl")]
[DataServiceKeyAttribute("Product")]
public class Item
{
public string Product { get; set; }
public int Quantity { get; set; }
public string Url { get; set; }
}
public partial class OrderItemData
{
#region Populate Service Data
static IList<Order> _orders;
static IList<Item> _items;
static OrderItemData()
{
_orders = new Order[]{
new Order(){ OrderId=0, Customer = "Peter Franken", Items = new List<Item>()},
new Order(){ OrderId=1, Customer = "Ana Trujillo", Items = new List<Item>()}};
_items = new Item[]{
new Item(){ Product="Chai", Quantity=10,
Url="http://northwindtraders.com/Teas" },
new Item(){ Product="Chang", Quantity=25,
Url="http://northwindtraders.com/Specialty"},
new Item(){ Product="Aniseed Syrup", Quantity = 5,
Url="http://northwindtraders.com/Specialty"},
new Item(){ Product="Chef Anton's Cajun Seasoning",
Quantity=30, Url="http://northwindtraders.com/Spices"}};
_orders[0].Items.Add(_items[0]);
_orders[0].Items.Add(_items[1]);
_orders[1].Items.Add(_items[2]);
_orders[1].Items.Add(_items[3]);
}
#endregion
public IQueryable<Order> Orders
{
get { return _orders.AsQueryable(); }
}
public IQueryable<Item> Items
{
get { return _items.AsQueryable(); }
}
}
public class OrderItems : DataService<OrderItemData>
{
// This method is called only once to initialize
//service-wide policies.
public static void InitializeService(DataServiceConfiguration
config)
{
config.SetEntitySetAccessRule("Orders",
EntitySetRights.AllRead |
EntitySetRights.AllWrite);
config.SetEntitySetAccessRule("Items",
EntitySetRights.AllRead |
EntitySetRights.AllWrite);
config.DataServiceBehavior.MaxProtocolVersion =
DataServiceProtocolVersion.V3;
}
}
}
The previous example returns the following result for the URI http://myservice/OrderItems.svc/Orders(0)?$expand=Items.
<entry xml:base="https://localhost:12345/OrderItems.svc/"
xmlns:d="https://schemas.microsoft.com/ado/2007/08/dataservices"
xmlns:m="https://schemas.microsoft.com/ado/2007/08/dataservices/metadata"
xmlns="http://www.w3.org/2005/Atom">
<id>https://localhost:12345/OrderItems.svc/Orders(0)</id>
<title type="text">0</title>
<updated>2009-07-25T21:12:30Z</updated>
<author>
<name>Peter Franken</name>
</author>
<link rel="edit" title="Order" href="Orders(0)" />
<link rel="https://schemas.microsoft.com/ado/2007/08/dataservices/related/Items"
type="application/atom+xml;type=feed" title="Items" href="Orders(0)/Items">
<m:inline>
<feed>
<title type="text">Items</title>
<id>https://localhost:12345/OrderItems.svc/Orders(0)/Items</id>
<updated>2009-07-25T21:12:30Z</updated>
<link rel="self" title="Items" href="Orders(0)/Items" />
<entry>
<id>https://localhost:12345/OrderItems.svc/Items('Chai')</id>
<title type="text" />
<updated>2009-07-25T21:12:30Z</updated>
<author>
<name />
</author>
<link rel="edit" title="Item" href="Items('Chai')" />
<category term="CustomDataService.Item"
scheme="https://schemas.microsoft.com/ado/2007/08/dataservices/scheme" />
<content type="application/xml">
<m:properties>
<d:Product>Chai</d:Product>
<d:Quantity m:type="Edm.Int32">10</d:Quantity>
</m:properties>
</content>
<orders:productname
xmlns:orders="http://schema.examples.microsoft.com/dataservices">Chai</orders:productname>
</entry>
<entry>
<id>https://localhost:12345/OrderItems.svc/Items('Chang')</id>
<title type="text" />
<updated>2009-07-25T21:12:30Z</updated>
<author>
<name />
</author>
<link rel="edit" title="Item" href="Items('Chang')" />
<category term="CustomDataService.Item"
scheme="https://schemas.microsoft.com/ado/2007/08/dataservices/scheme" />
<content type="application/xml">
<m:properties>
<d:Product>Chang</d:Product>
<d:Quantity m:type="Edm.Int32">25</d:Quantity>
</m:properties>
</content>
<orders:productname
xmlns:orders="http://schema.examples.microsoft.com/dataservices">Chang</orders:productname>
</entry>
</feed>
</m:inline>
</link>
<category term="CustomDataService.Order"
scheme="https://schemas.microsoft.com/ado/2007/08/dataservices/scheme" />
<content type="application/xml">
<m:properties>
<d:Customer>Peter Franken</d:Customer>
</m:properties>
</content>
</entry>