EntityPropertyMappingAttribute Class
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
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.
public ref class EntityPropertyMappingAttribute sealed : Attribute[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=true, Inherited=true)]
public sealed class EntityPropertyMappingAttribute : Attribute[<System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple=true, Inherited=true)>]
type EntityPropertyMappingAttribute = class
inherit AttributePublic NotInheritable Class EntityPropertyMappingAttribute
Inherits Attribute- Inheritance
- Attributes
Examples
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.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.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>
Remarks
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.
Constructors
| EntityPropertyMappingAttribute(String, String, String, String, Boolean) |
Creates an instance of the EntityPropertyMappingAttribute to map a property to a custom feed element. |
| EntityPropertyMappingAttribute(String, SyndicationItemProperty, SyndicationTextContentKind, Boolean) |
Creates a new instance of the EntityPropertyMappingAttribute. |
Properties
| KeepInContent |
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. |
| SourcePath |
Gets the name of the property of the syndication item that will be mapped to the specified element of the feed. |
| TargetNamespacePrefix |
Gets a string value that, together with TargetNamespaceUri, specifies the namespace in which the TargetPath element exists. |
| TargetNamespaceUri |
Gets a string value that specifies the namespace URI of the element specified by the TargetPath property. |
| TargetPath |
Gets the name of the custom target in the feed to which the property is mapped. |
| TargetSyndicationItem |
Gets a property on the SyndicationItem class. |
| TargetTextContentKind |
Gets the type of content of the property mapped by EntityPropertyMappingAttribute. |
| TypeId |
When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute) |
Methods
| Equals(Object) |
Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute) |
| GetHashCode() |
Returns the hash code for this instance. (Inherited from Attribute) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| 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) |
| Match(Object) |
When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| ToString() |
Returns a string that represents the current object. (Inherited from Object) |
Explicit Interface Implementations
| _Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) |
Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute) |
| _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) |
| _Attribute.GetTypeInfoCount(UInt32) |
Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute) |
| _Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) |
Provides access to properties and methods exposed by an object. (Inherited from Attribute) |
