EntityPropertyMappingAttribute Class
 
System_CAPS_noteNote

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Attribute that specifies a custom mapping between properties of an entity type and elements of an entry in a feed returned by WCF Data Services. 

Namespace:   System.Data.Services.Common
Assembly:  System.Data.Services.Client (in System.Data.Services.Client.dll)

SystemObject
   SystemAttribute
    System.Data.Services.CommonEntityPropertyMappingAttribute

[AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = true, 
	Inherited = true)]
public sealed class EntityPropertyMappingAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Class, AllowMultiple = true, 
	Inherited = true)]
public ref class EntityPropertyMappingAttribute sealed : Attribute
[<Sealed>]
[<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = true,
    Inherited = true)>]
type EntityPropertyMappingAttribute = 
    class
        inherit Attribute
    end
<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple := True,
	Inherited := True)>
Public NotInheritable Class EntityPropertyMappingAttribute
	Inherits Attribute
NameDescription
System_CAPS_pubmethod EntityPropertyMappingAttribute

Creates an instance of the EntityPropertyMappingAttribute to map a property to a custom feed element.

System_CAPS_pubmethod EntityPropertyMappingAttribute

Creates a new instance of the EntityPropertyMappingAttribute.

NameDescription
System_CAPS_pubproperty

Gets a Boolean value that indicates whether a property value should be repeated both in the content section of the feed and in the mapped location.

System_CAPS_pubproperty

Gets the name of the property of the syndication item that will be mapped to the specified element of the feed.

System_CAPS_pubproperty

Gets a string value that, together with , specifies the namespace in which the element exists.

System_CAPS_pubproperty

Gets a string value that specifies the namespace URI of the element specified by the property.

System_CAPS_pubproperty

Gets the name of the custom target in the feed to which the property is mapped.

System_CAPS_pubproperty

Gets a property on the SyndicationItem class.

System_CAPS_pubproperty

Gets the type of content of the property mapped by EntityPropertyMappingAttribute.

System_CAPS_pubproperty

When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)

NameDescription
System_CAPS_pubmethod Equals

This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)

System_CAPS_pubmethod GetHashCode

Returns the hash code for this instance.(Inherited from Attribute.)

System_CAPS_pubmethod GetType

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethod IsDefaultAttribute

When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)

System_CAPS_pubmethod Match

When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)

System_CAPS_pubmethod ToString

Returns a string that represents the current object.(Inherited from Object.)

NameDescription
System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetIDsOfNames

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfo

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfoCount

Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeInvoke

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

The EntityPropertyMappingAttribute is used to define custom feed mapping in the data model of a reflection provider. This attribute is also applied to generated client data service classes when the metadata used to generate the classes indicates that custom feed mappings are defined in the data model. This information is necessary to make sure that the client can create and consume messages that support custom feeds. For more information, see Feed Customization (WCF Data Services).

In the following example, both properties of the Order type are mapped to existing feed elements. The Product property of the Item type is mapped to a custom feed attribute in a separate 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", "productname",
     "orders", "http://schema.examples.microsoft.com/dataservices", true)]
    [DataServiceKeyAttribute("Product")]
    public class Item
    {
        public string Product { get; set; }
        public int Quantity { 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 },
              new Item(){ Product="Chang", Quantity=25 },
              new Item(){ Product="Aniseed Syrup", Quantity = 5 },
              new Item(){ Product="Chef Anton's Cajun Seasoning", Quantity=30}};
            _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.V2;
        }
    }
}
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", "productname", _
        "orders", "http://schema.examples.microsoft.com/dataservices", True)> _
    <DataServiceKeyAttribute("Product")> _
    Public Class Item
        Private _product As String
        Private _quantity As Integer
        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
    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}, _
              New Item() With {.Product = "Chang", .Quantity = 25}, _
              New Item() With {.Product = "Aniseed Syrup", .Quantity = 5}, _
              New Item() With {.Product = "Chef Anton's Cajun Seasoning", .Quantity = 30}}
            _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.V2
        End Sub
    End Class
End Namespace

The previous example returns the following result for the URI http://myservice/OrderItems.svc/Orders(0)?$expand=Items.

<entry xml:base="http://localhost:12345/OrderItems.svc/" 
       xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices" 
       xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata" 
       xmlns="http://www.w3.org/2005/Atom">
  <id>http://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="http://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>http://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>http://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="http://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>http://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="http://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="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" />
  <content type="application/xml">
    <m:properties>
      <d:Customer>Peter Franken</d:Customer>
    </m:properties>
  </content>
</entry>
.NET Framework
Available since 3.5
Silverlight
Available since 4.0

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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