EntityPropertyMappingAttribute Class
Attribute that specifies a custom mapping between properties of an entity type and elements of an entry in an Open Data Protocol (OData) feed returned by the data service.
Inheritance Hierarchy
System.Object
System.Attribute
System.Data.Services.Common.EntityPropertyMappingAttribute
Namespace: System.Data.Services.Common
Assembly: Microsoft.Data.OData (in Microsoft.Data.OData.dll)
Syntax
'Declaration
<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple := True, Inherited := True)> _
Public NotInheritable Class EntityPropertyMappingAttribute _
Inherits Attribute
'Usage
Dim instance As EntityPropertyMappingAttribute
[AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
public sealed class EntityPropertyMappingAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Class, AllowMultiple = true, Inherited = true)]
public ref class EntityPropertyMappingAttribute sealed : public Attribute
[<SealedAttribute>]
[<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = true, Inherited = true)>]
type EntityPropertyMappingAttribute =
class
inherit Attribute
end
public final class EntityPropertyMappingAttribute extends Attribute
The EntityPropertyMappingAttribute type exposes the following members.
Constructors
Name | Description | |
---|---|---|
EntityPropertyMappingAttribute(String, SyndicationItemProperty, SyndicationTextContentKind, Boolean) | Creates a new instance of the EntityPropertyMappingAttribute. | |
EntityPropertyMappingAttribute(String, String, String, String, Boolean) | Creates an instance of the EntityPropertyMappingAttribute to map a property to a custom feed element. |
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Properties
Name | Description | |
---|---|---|
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 TargetPathelement 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 the syndication item in the entry targeted by the mapping. | |
TargetTextContentKind | Gets the type of content of the property mapped by EntityPropertyMappingAttribute. | |
TypeId | (Inherited from Attribute.) |
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Methods
Name | Description | |
---|---|---|
Equals | (Inherited from Attribute.) | |
GetHashCode | (Inherited from Attribute.) | |
GetType | (Inherited from Object.) | |
IsDefaultAttribute | (Inherited from Attribute.) | |
Match | (Inherited from Attribute.) | |
ToString | (Inherited from Object.) |
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Explicit Interface Implementations
Name | Description | |
---|---|---|
_Attribute.GetIDsOfNames | (Inherited from Attribute.) | |
_Attribute.GetTypeInfo | (Inherited from Attribute.) | |
_Attribute.GetTypeInfoCount | (Inherited from Attribute.) | |
_Attribute.Invoke | (Inherited from Attribute.) |
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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 required to make sure that the client can create and consume messages that support custom feeds. For more information, see Feed Customization (WCF Data Services).
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.
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, _
"https://northwindtraders.com/Products")> _
<EntityPropertyMappingAttribute("Url", _
SyndicationItemProperty.LinkHref, false, _
SyndicationCriteria.LinkRel, _
"https://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 = "https://northwindtraders.com/Teas"}, _
New Item() With {.Product = "Chang", .Quantity = 25, _
.Url = "https://northwindtraders.com/Specialty"}, _
New Item() With {.Product = "Aniseed Syrup", .Quantity = 5, _
.Url = "https://northwindtraders.com/Specialty"}, _
New Item() With {.Product = "Chef Anton's Cajun Seasoning", _
.Quantity = 30, .Url = "https://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,
"https://northwindtraders.com/Products")]
[EntityPropertyMappingAttribute("Url",
SyndicationItemProperty.LinkHref, false,
SyndicationCriteria.LinkRel,
"https://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="https://northwindtraders.com/Teas" },
new Item(){ Product="Chang", Quantity=25,
Url="https://northwindtraders.com/Specialty"},
new Item(){ Product="Aniseed Syrup", Quantity = 5,
Url="https://northwindtraders.com/Specialty"},
new Item(){ Product="Chef Anton's Cajun Seasoning",
Quantity=30, Url="https://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 https://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="https://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="https://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="https://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>
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
See Also
Reference
System.Data.Services.Common Namespace
Other Resources
How to: Create a Data Service Using the Reflection Provider (WCF Data Services)