EntityPropertyMappingAttribute Class

 

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)

System.Object
  System.Attribute
    System.Data.Services.Common.EntityPropertyMappingAttribute

[AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = true, 
	Inherited = true)]
public sealed class EntityPropertyMappingAttribute : Attribute

NameDescription
System_CAPS_pubmethodEntityPropertyMappingAttribute(String, String, String, String, Boolean)

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

System_CAPS_pubmethodEntityPropertyMappingAttribute(String, SyndicationItemProperty, SyndicationTextContentKind, Boolean)

Creates a new instance of the EntityPropertyMappingAttribute.

NameDescription
System_CAPS_pubpropertyKeepInContent

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_pubpropertySourcePath

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

System_CAPS_pubpropertyTargetNamespacePrefix

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

System_CAPS_pubpropertyTargetNamespaceUri

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

System_CAPS_pubpropertyTargetPath

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

System_CAPS_pubpropertyTargetSyndicationItem

Gets a property on the SyndicationItem class.

System_CAPS_pubpropertyTargetTextContentKind

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

System_CAPS_pubpropertyTypeId

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

NameDescription
System_CAPS_pubmethodEquals(Object)

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_pubmethodGetHashCode()

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

System_CAPS_pubmethodGetType()

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

System_CAPS_pubmethodIsDefaultAttribute()

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_pubmethodMatch(Object)

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

System_CAPS_pubmethodToString()

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

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

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

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

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

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfoCount(UInt32)

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

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

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;
        }
    }
}

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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