The SharePoint 2010 Representational State Transfer (REST) interface is a WCF Data Service that allows you to use construct HTTP requests to query SharePoint list data. Like all RESTful Web services, the SharePoint REST interface maps HTTP verbs to data operations, as shown in the following table.

Note:

In practice, many firewalls and other network intermediaries block HTTP verbs other than GET and POST. To work around this issue, WCF Data Services (and the OData standard) support a technique known as "verb tunneling." In this technique, PUT, DELETE, and MERGE requests are submitted as a POST request, and an X-HTTP-Method header specifies the actual verb that the recipient should apply to the request. For more information, see X-HTTP-Method on MSDN and OData: Operations (the Method Tunneling through POST section) on the OData Web site.

A RESTful service models data entities, in this case SharePoint lists, as HTTP resources that can be addressed by a URL. You can append query strings to the URLs in order to specify filter criteria or query logic. The following examples show some URLs that correspond to simple REST operations.

http://localhost/_vti_bin/listdata.svc/Parts

The preceding URL returns the contents of the Parts list in XML format as an Atom feed.

http://localhost/_vti_bin/listdata.svc/Parts(3)

The preceding URL returns the Parts list item with an ID value of 3 as an Atom feed.

http://localhost/_vti_bin/listdata.svc/Parts?$orderby=Name

The preceding URL returns the Parts list as an Atom feed, ordered by the Name field.

However, you don't need to manually construct HTTP requests in order to use the SharePoint REST interface. When you use Visual Studio 2010 to create a SharePoint client application, Visual Studio will generate a WCF Data Services Framework service proxy when you add a reference to the service. The service proxy provides strongly-typed entity classes and enables you to use LINQ expressions to build queries. Behind the scenes, the service proxy manages the details of building and submitting requests to the service.

The SharePoint REST interface is based on the REST-based Open Data protocol (OData) for Web-based data services, which extends the Atom and AtomPub syndication formats to exchange XML data over HTTP. Because OData is a platform-independent open standard, the SharePoint REST interface is a great way to access SharePoint list data from platforms on which the CSOM may be unavailable to you, such as from non-Windows–based operating systems. However, the REST interface only provides access to list data—if you need to manipulate other data on your SharePoint site, you will need to use the CSOM. The REST implementation can also return the output in JavaScript Object Notation (JSON) format as an alternative to an ATOM feed. JSON is a compact representation of the returned results that can be easily parsed by JavaScript clients.

Note:

For background information about Windows Communication Foundation (WCF)–based REST services, see Overview of REST in WCF on MSDN. For product documentation for the SharePoint REST interface, see SharePoint Foundation REST Interface on MSDN. For more information about creating a service proxy for the REST interface, see Query SharePoint Foundation with ADO.NET Data Services on MSDN. For more information about OData, Atom, and REST, see Open Data Protocol by Example on MSDN and the Open Data Protocol Web site. ADO.NET Data Services and WCF Data Services are the same thing—WCF Data Services is now the official name.

Using the Service Proxy

The WCF Data Services service proxy for the SharePoint REST interface includes classes that provide strongly-typed representations of the lists and content types in your SharePoint site. At the top level in the service proxy object model, a data context class that inherits from DataServiceContext provides the starting point for all your service calls. In this way, it performs a similar role to the data context class that you use with the LINQ to SharePoint provider. When you want to perform a data operation using the REST interface, your first step is always to instantiate the data context class to the WCF service endpoint for your SharePoint site. For example, in the Client Reference Implementation, the data context class is named PartsDataContext.

C#

PartsDataContext context = new PartsDataContext( new Uri("http://localhost/sites/sharepointlist/_vti_bin/listdata.svc"));

The data context class allows you to specify contextual information for the operations, such as user credentials, and it provides methods that you can use to build and execute REST queries. Your code runs in a browser—using either JavaScript or Silverlight—the calls to SharePoint will use the security context already established by the browser session. You can use the LINQ query syntax to build query expressions. For example, the following method, which was taken from the Client Reference Implementation, retrieves parts that start with the SKU search string.

C#

var partsQuery = (DataServiceQuery<PartsItem>) context.Parts.Where(p => p.SKU.StartsWith(SearchSku)) .Select(p => new PartsItem { Title = p.Title, SKU = p.SKU, Id = p.Id, Description = p.Description }); // Execute query. query.BeginExecute(DisplayParts, query);

The preceding example demonstrates various key points of submitting queries to the REST interface by using the service proxy:

• • It creates a LINQ expression from the data context object.

  • The LINQ expression returns a query in the form of a DataServiceQuery<TElement> instance. This is a WCF Data Services class that represents a query request to a service, where the query returns a collection of TElement instances. The DataServiceQuery<TElement> class implements the IQueryable interface, which allows you to use the LINQ extension methods provided by the Queryable class to query the result set. In the preceding example, TElement is PartsItem. The DataServiceQuery.BeginExecute method is used to send the query to the REST service asynchronously, passing in the callback delegate and the query object as arguments. The results of the query in partsQuery are not available until the callback delegate, DisplayParts, is invoked.

  • The proxy generates a REST statement from the LINQ expression and submits it to the REST service, as shown here.

    • • • • • http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/Parts() ?$filter=startswith(SKU,'sku') &$select=Title,SKU,Id,Description

Note:

You can also use the CreateQuery method to create the query object explicitly from the data context. In the previous example, where a LINQ statement was specified without calling CreateQuery, the WCF Data Services proxy created the query object implicitly when the results of the LINQ statement were cast to a DataServiceQuery<PartsItem> instance. For example, the following statement is functionally equivalent to the previous code example:

context.CreateQuery<PartsItem>("Parts").Where(p => p.SKU.StartsWith(SearchSku)).Select(p => new PartsItem { Title = p.Title, SKU = p.SKU, Id = p.Id, Description = p.Description });

In general, the implicit approach is preferred for readability and simplicity.

The callback method iterates through the query results and adds each item to the Parts observable collection. The Parts collection is bound to a UI control that renders the results in a grid. Because this is a Silverlight application, you must use the Dispatcher.BeginInvoke method to execute the data binding logic asynchronously on the UI thread.

C#

Dispatcher.BeginInvoke( () => { Parts.Clear(); DataServiceQuery<PartsItem> query = (DataServiceQuery<PartsItem>) result.AsyncState; var partResults = query.EndExecute(result); foreach (var part in partResults) { Parts.Add(part); } });

Although the queries themselves will vary, the pattern of use remains broadly the same for all REST interface queries.

How Does the REST Interface Work?

When you create a WCF Data Services service proxy for the REST interface, you can use it to send a query to the REST interface in one of three ways:

• • You can use the data context class to create a DataServiceQuery<TElement> instance, as seen in the preceding code examples. When you use this approach, you submit a LINQ expression to the service proxy. The service proxy converts the LINQ expression into a URL-based REST request and submits it to the REST interface.

  • You can use view projection, in which case the DataServiceQuery<TElement> is created implicitly. This approach is described in more detail in the next section.

  • You can use the data context class to submit a URL-based REST request directly, as shown by the following code example.

    • • • C#

          • • context.Execute<PartsItem>(new uri("http://contoso/_vti_bin/listdata.svc/Parts() ?$filter=startswith(SKU,'Sku2') &$select=Title,SKU,Id,Description"));

The LINQ expression used on the client is specific to the WCF Data Services proxy, which converts the LINQ expression into a REST statement. On the SharePoint server, the REST service implementation translates the REST statement into a LINQ to SharePoint expression. This translation process is not visible to the developer. The important thing to note is that the LINQ expressions you submit to the service proxy on the client are completely independent of the LINQ to SharePoint expressions that the REST service implementation generates in order to fulfill the request. The LINQ to SharePoint provider converts the server-generated LINQ expressions into CAML, and then it executes the CAML queries against your SharePoint lists. The REST interface returns the results to the service proxy in JSON format or as an Atom feed, using the OData protocol. The service proxy then converts the response into strongly-typed entity instances and returns the results to the caller. The following illustration shows this process.

The SharePoint REST interface

It can be instructive to see how LINQ expressions are translated into REST queries, and how these REST queries translate into the HTTP requests and responses that are exchanged between the client and the server. Using the preceding LINQ expression as an example, the process is as follows:

• 1. The proxy forms a REST query from the LINQ expression.

     1. 1. 1. 1. 1. http://localhost/sites/sharepointlist/_vti_bin/listdata.svc/Parts() ?$filter=startswith(SKU,'sku') &$select=Title,SKU,Id,Description

  2. The proxy submits the REST query to the server as an HTTP GET request.

• • • • • • 1. HTTP Request GET http://localhost/sites/sharepointlist/_vti_bin/listdata.svc/Parts()?$filter=startswith(SKU,'sku1')&$select=Title,SKU,Id,Description HTTP/1.1 Accept: application/atom+xml,application/xml Accept-Language: en-US Referer: file:///C:/spg3/Trunk/Source/Client/Client.REST/Client.REST.Silverlight/Bin/Debug/Client.REST.Silverlight.xap Accept-Encoding: identity DataServiceVersion: 2.0;NetFx MaxDataServiceVersion: 2.0;NetFx User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.3; MS-RTC LM 8; .NET4.0C; .NET4.0E) Host: contoso Connection: Keep-Alive

• 3. The server responds with an OData-formatted result set. (The HTTP headers have been omitted for brevity.)

• • • • 1. HTTP Response

           1. 1. <?xml version="1.0" encoding="utf-8" standalone="yes"?> <feed xml:base="http://contoso/sites/sharepointlist/_vti_bin/listdata.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"> <title type="text">Parts</title> <id>http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/Parts</id> <updated>2010-05-30T14:20:47Z</updated> <link rel="self" title="Parts" href="Parts" /> <entry m:ETag="W/&quot;2&quot;"> <id>http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/Parts(2) </id> <title type="text">SHAFT - PUMP 1</title> <updated>2010-05-21T14:06:12-04:00</updated> <author> <name /> </author> <link rel="edit" title="PartsItem" href="Parts(2)" /> <category term="Microsoft.SharePoint.DataService.PartsItem" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" /> <content type="application/xml"> <m:properties> <d:Title>SHAFT - PUMP 1</d:Title> <d:SKU>SKU1</d:SKU> <d:Description m:null="true" /> <d:Id m:type="Edm.Int32">2</d:Id> </m:properties> </content> </entry> </feed>

• 4. The WCF Data Services proxy invokes the DisplayParts delegate and provides the results from the request as a strongly-typed collection of PartsItem instances.

Query Efficiency with the REST Interface

In order to understand the performance implications of using the REST interface, you need to understand what happens when you request data from the service:

• 1. You submit a LINQ expression to the service proxy.

  2. The service proxy converts your LINQ expression into a URL-based REST request, and then submits the request to the REST interface on the server.

  3. The REST interface converts the REST request into a LINQ to SharePoint expression.

  4. The LINQ to SharePoint provider converts the LINQ expression into a CAML query.

Joins

You have some control over whether the REST interface generates LINQ expressions with efficient syntax. You can gain an insight into the performance of REST-based queries by understanding how some specific REST constructs are implemented by the service.

The REST interface does not support explicit list joins. You can use the Expand method to navigate from one entity to a related entity. Although this appears similar to a join, it actually results in the execution of additional list queries on the server. If required, the REST provider performs an implicit join to satisfy the where clause. However, for each item in the result set, the Expand method causes an additional list query to retrieve the related entity instance that corresponds to the value in a lookup column. For example, consider the following query that retrieves a list of inventory locations ordered by Part.SKU.

C#

var query = (DataServiceQuery<InventoryLocationsItem>) context.InventoryLocations .Expand("Part") .Where(p => p.Part.SKU.StartsWith(SearchSku)) .OrderBy(p => p.Part.SKU);

The Expand method in our LINQ query is translated to an &expand="Part" query string in the REST request URL, as shown here.

http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/InventoryLocations() ?$filter=startswith(Part/SKU,'sku') &$orderby=Part/SKU &$expand=Part

In this case, the following actions take place in order to execute the query on the server:

• 1. A list join is performed between the Inventory Locations list and the Parts list, in order to satisfy the where clause match on the part SKU. From the REST statement, the implicit join occurs because Part/SKU in the startswith statement follows a lookup field relationship.

  2. The inventory location items are ordered by part SKU.

  3. For each inventory item in the result set, a query is executed on the server to retrieve the related part to satisfy the expand clause.

  4. The results are formatted using the OData protocol and returned to the caller.

As you can see, this operation is going to be less efficient than submitting a CAML query with a join predicate where all values can be retrieved in a single list query. However, the CSOM is the only data access mechanism that supports explicit joins. The CSOM allows you to submit a CAML query that specifies a list join and a view projection directly from your client-side logic.

Projections

The REST interface supports view projections. As described in Data Access in SharePoint 2010, view projections improve query efficiency by limiting the field values returned to only those fields that are of interest. For example, the following query uses a view projection to select parts, based on a partial part SKU match.

C#

context.Parts.Where(p => p.SKU.StartsWith(SearchSku)) .Select(p => new PartsItem { Title = p.Title, SKU = p.SKU, Id = p.Id, Description = p.Description });

The service proxy translates this query into the following REST request URL, and then it parses the response feed into a collection of PartsItem instances.

http://contoso/_vti_bin/listdata.svc/Parts() ?$filter=startswith(SKU,'SKU2') &$select=Title,SKU,Id,Description

You can also perform query projections explicitly on the query object. This can be useful as a concise way to query multiple related entities.

C#

var query = (DataServiceQuery<InventoryLocationsItem>)context. CreateQuery<InventoryLocationsItem>("InventoryLocations") .Expand("Part") .AddQueryOption("$select", "BinNumber,Quantity,Title,Id,PartId,Part/SKU,Part/Title") .Where(p => p.Part.SKU.StartsWith(SearchSku)).OrderBy(p => p.Part.SKU);

In this case, only the BinNumber, Quantity, Title, ID, and PartId values are retrieved from each inventory location item, and only SKU and Title are retrieved from each part item. If you use view projections, you need to be aware that the result set will include null values for the fields that you have omitted. For example, if you attempt to access inventoryItem.Part.Description from a returned result, the value will always be null because your query excluded the Part.Description property. The expression results in the following REST query.

http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/InventoryLocations() ?$filter=startswith(Part/SKU,'sku') &$orderby=Part/SKU &$expand=Part &$select=BinNumber,Quantity,Title,Id,PartId,Part/SKU,Part/Title

In addition to projecting fields from related entities onto a target entity—such as projecting Part fields onto an Inventory Location entity, as illustrated in the preceding example—you can also create a new view entity that combines the fields of interest. The following query populates a PartInvView instance that contains fields from the Inventory Locations list and the Parts list.

C#

var query = (DataServiceQuery<PartInvView>)context.InventoryLocations .Where(p => p.Part.SKU.StartsWith(SearchSku)) .OrderBy(p => p.Part.SKU) .Select((i) => new PartInvView { BinNumber = i.BinNumber, Quantity=i.Quantity, InvTitle=i.Title, InvId=i.Id, PartId=i.PartId, SKU=i.Part.SKU, PartTitle=i.Part.Title });

This projection produces the same REST query as the previous example. The only difference is that the service proxy will use the results to populate a collection of PartInvView instances, instead of a collection of InventoryLocationsItem instances.

http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/InventoryLocations() ?$filter=startswith(Part/SKU,'sku') &$orderby=Part/SKU &$expand=Part &$select=BinNumber,Quantity,Title,Id,PartId,Part/SKU,Part/Title

You should consider using view projections whenever you are retrieving lists of items, in order to reduce network traffic and improve query efficiency.

Concurrency Management

By default, the REST implementation supports optimistic concurrency. This means that no locks are placed on the underlying database tables between the time you read an item and the time you write an update to the item. This is a standard approach to service development that prevents clients from controlling precious database resources and impacting other clients. To detect whether an underlying entity has changed between a read operation and an update operation, the REST interface records information about the version of the entity you originally retrieved. If this version information has changed when you perform the update operation, the REST interface will return the following error.

XML

<?xml version="1.0" encoding="utf-8" standalone="yes"?><error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata"> <code></code> <message xml:lang="en-US"> Since entity type 'Microsoft.SharePoint.DataService.PartsItem' has one or more ETag properties, If-Match HTTP header must be specified for DELETE/PUT operations on this type. </message></error>

The OData standard used by the REST interface uses ETags to perform this concurrency control. ETags are a mechanism defined by the HTTP protocol for efficient cache control between a client browser and a Web server. An ETag consists of a unique value that the Web server specifies to identify a particular version of a resource. When you update an entity, the service proxy will automatically add an ETag to the HTTP request. The ETag value matches the value provided by the service when you retrieved the data that you want to update. However, if the server-side data changes between the point at which you retrieve it and the point at which you persist an update, the ETag values will not match, and the server will detect a conflict. In this case, you receive the error described earlier. This error may also occur within your code if you have more than one data context retrieving the same entity, or if you create a new data context to save an item that was previously retrieved. If you want to persist your changes regardless of whether the underlying entity has changed, you can use the following code to force the service to apply your updates.

C#

context.MergeOption = MergeOption.OverwriteChanges;context.AttachTo("Parts", currentItem, "*");

The DataServiceContext.AttachTo method instructs the context object to track the object that you intend to update. By specifying an ETag value of *, you are telling the service to overwrite the object, regardless of the ETag value.

PUT and MERGE Operations

The WCF Data Services proxy uses two different HTTP verbs for different update operations:

• • A PUT request is used to update an entire entity. If no values are specified for fields in the entity, the fields will be set to default values.

  • A MERGE request is used to update only those field values that have changed. Any fields that are not specified by the operation will remain set to their current value.

Because the service proxy and the DataServiceContext class manage the creation of HTTP requests, you generally do not need to worry about these details when you use the REST interface from managed code. However, when you use JavaScript, you must manually create the HTTP requests and, as such, you need to understand this distinction. The next section provides more details about using the REST interface from JavaScript.

Using the REST Interface from JavaScript

Using the REST interface from JavaScript requires some extra work, because you can't generate a service proxy to build requests and handle responses. In order to use the REST interface to create entities from JavaScript, you must perform the following actions:

• • Create an HTTP request using the POST verb.

  • Use the service URL of the list to which you want to add an entity as the target for the POST.

  • Set the content type to application/json.

  • Serialize the JSON objects that represent your new list items as a string, and add this value to the request body.

This is illustrated by the following code, which creates a new inventory location item. This simplified example was taken from the RestScripts.js file in the Client Reference Implementation.

JavaScript

var url = 'http://localhost/sites/sharepointlist/_vti_bin/listdata.svc/InventoryLocations'; var inventoryLocation = {}; // Insert a new Part location. inventoryLocation.PartId = $('#hidPartId').val(); inventoryLocation.BinNumber = $('#binText').val(); inventoryLocation.Quantity = $('#quantityText').val(); var body = Sys.Serialization.JavaScriptSerializer.serialize(inventoryLocation); $.ajax({ type: 'POST', url: url, contentType: 'application/json', processData: false, data: body, success: function () { alert('Inventory Location Saved.'); } });

Updating an existing entity is a little more complex. If you've worked with REST services before, you might be tempted to use an HTTP PUT operation to update the entity. However, this approach can be problematic. Even if you load the entire entity, keep the entity in memory, and use the entity in a PUT operation, you may still experience problems with field values. Experience with this approach has shown issues with date time conversion and the population of lookup fields. This is because the OData protocol assumes that a PUT operation will update the entire entity, and any fields that are not explicitly specified are reset to their default values, most of which are a null value. A better approach is to use the HTTP MERGE operation, which updates only the fields that have changed. This approach also improves performance, because you don't need to initially retrieve a full representation of the entity just to send it back to the server to update it.

To use this approach to update an existing entity, you must perform the following actions:

• • Create an HTTP request using the POST verb.

  • Add an X-HTTP-Method header with a value of MERGE.

  • Use the service URL of the list item you want to update as the target for the POST—for example, _vti_bin/listdata.svc/InventoryLocations(XXX), where XXX is the ID of the list item.

  • Add an If-Match header with a value of the entity's original ETag.

This is illustrated by the following code, which updates an existing inventory location item. This simplified example was taken from the RestScripts.js file in the Client Reference Implementation.

C#

var locationId = $('#hidLocationId').val(); var url = 'http://localhost/sites/sharepointlist/_vti_bin/listdata.svc/InventoryLocations'; var beforeSendFunction; var inventoryLocationModifications = {}; // Update the existing Part location. url = url + "(" + locationId + ")"; beforeSendFunction = function (xhr) { xhr.setRequestHeader("If-Match", inventoryLocation.__metadata.ETag); // Using MERGE so that the entire entity doesn't need to be sent over the wire. xhr.setRequestHeader("X-HTTP-Method", 'MERGE'); } inventoryLocationModifications.BinNumber = $('#binText').val(); inventoryLocationModifications.Quantity = $('#quantityText').val(); var body = Sys.Serialization.JavaScriptSerializer.serialize(inventoryLocationModifications); $.ajax({ type: 'POST', url: url, contentType: 'application/json', processData: false, beforeSend: beforeSendFunction, data: body, success: function () { alert('Inventory Location Saved.'); } });

For more information about update and merge operations, see Section 2.6, "Updating Entries," in OData: Operations.

Batching

The OData protocol used by WCF Data Services supports the batching of multiple REST queries into a single HTTP request. Using batching reduces chattiness, uses network bandwidth more efficiently, and improves the responsiveness of your applications. In order to use batching, you simply submit multiple queries at the same time using the DataServiceContext.BeginExecuteBatch method.

C#

context.BeginExecuteBatch(DisplayParts, context, invQuery, partsQuery);

In this example, two queries are submitted: invQuery and partsQuery. The list of queries submitted is variable, so while this example shows two queries, additional queries could be added. When the server finishes executing a batch of requests, it returns a collection of results to the client. This is illustrated by the following code example.

C#

// Get the batch response. DataServiceResponse Response = context.EndExecuteBatch(result); // Loop through each operation.foreach (QueryOperationResponse operation in Response) { if (operation.Error != null) { throw operation.Error; } if (oOperation is QueryOperationResponse<InventoryLocationsItem>) { ProcessInventoryLocation(operation); } if (operation is QueryOperationResponse<PartsItem>) { ProcessParts(operation); } }

The service proxy sends batch requests in a multi-part message (MIME) format to the REST service. Notice that the message contains two GET requests, one for Inventory Locations and one for Parts.

HTTP Request

POST http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/$batch HTTP/1.1 Content-Type: multipart/mixed; boundary=batch_16c7085d-ad1e-4962-b5e3-e7c83452b95a Accept-Language: en-US Referer: file:///C:/spg3/Trunk/Source/Client/Client.REST/Client.REST.Silverlight/Bin/Debug/Client.REST.Silverlight.xap Authorization: Negotiate oXcwdaADCgEBoloEWE5UTE1TU1AAAwAAAAAAAABYAAAAAAAAAFgAAAAAAAAAWAAAAAAAAABYAAAAAAAAAFgAAAAAAAAAWAAAABXCiOIGAbAdAAAAD4N0FBUwhwapfSA5hPbF5jGjEgQQAQAAAPUXp1AtIpqEAAAAAA== Accept-Encoding: identity DataServiceVersion: 1.0;NetFx MaxDataServiceVersion: 2.0;NetFx Accept: application/atom+xml,application/xml User-Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; InfoPath.3; MS-RTC LM 8; .NET4.0C; .NET4.0E) Host: contoso Connection: Keep-Alive Pragma: no-cache Content-Length: 717 --batch_16c7085d-ad1e-4962-b5e3-e7c83452b95a Content-Type: application/http Content-Transfer-Encoding: binary GET http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/InventoryLocations()?$filter=startswith(Part/SKU,'sku11')&$orderby=Part/SKU&$expand=Part&$select=BinNumber,Quantity,Title,Id,PartId,Part/SKU,Part/Title HTTP/1.1 DataServiceVersion: 2.0;NetFx --batch_16c7085d-ad1e-4962-b5e3-e7c83452b95a Content-Type: application/http Content-Transfer-Encoding: binary GET http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/Parts()?$filter=startswith(SKU,'sku11')&$select=Title,SKU,Id,Description HTTP/1.1 DataServiceVersion: 2.0;NetFx --batch_16c7085d-ad1e-4962-b5e3-e7c83452b95a--

The response to the batch execution also uses MIME formatting, and it contains two HTTP responses, one for each query submitted.

Http Response

HTTP/1.1 202 Accepted Cache-Control: no-cache Content-Type: multipart/mixed; boundary=batchresponse_8ad6352b-ac02-4946-afc5-1df735bb7f55 Server: Microsoft-IIS/7.5 SPRequestGuid: 5f0f516c-78cf-4ffe-b37e-1c9e7168ef18 Set-Cookie: WSS_KeepSessionAuthenticated={0a9aa553-ad9a-401f-862a-2566fe4c94f4}; path=/ X-SharePointHealthScore: 0 DataServiceVersion: 1.0; X-AspNet-Version: 2.0.50727 WWW-Authenticate: Negotiate oRswGaADCgEAoxIEEAEAAABDh+CIwTbjqQAAAAA= Persistent-Auth: true X-Powered-By: ASP.NET MicrosoftSharePointTeamServices: 14.0.0.4762 Date: Sun, 30 May 2010 16:34:19 GMT Content-Length: 4204 --batchresponse_8ad6352b-ac02-4946-afc5-1df735bb7f55 Content-Type: application/http Content-Transfer-Encoding: binary HTTP/1.1 200 OK Cache-Control: no-cache DataServiceVersion: 2.0; Content-Type: application/atom+xml;charset=utf-8 <?xml version="1.0" encoding="utf-8" standalone="yes"?> <feed xml:base="http://contoso/sites/sharepointlist/_vti_bin/listdata.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"> <title type="text">InventoryLocations</title> <id>http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/InventoryLocations</id> <updated>2010-05-30T16:34:19Z</updated> <link rel="self" title="InventoryLocations" href="InventoryLocations" /> <entry m:ETag="W/&quot;1&quot;"> <id>http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/InventoryLocations(18)</id> <title type="text"></title> <updated>2010-05-21T14:06:13-04:00</updated> <author> <name /> </author> <link rel="edit" title="InventoryLocationsItem" href="InventoryLocations(18)" /> <link rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/Part" type="application/atom+xml;type=entry" title="Part" href="InventoryLocations(18)/Part"> <m:inline> <entry m:ETag="W/&quot;2&quot;"> <id>http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/Parts(12)</id> <title type="text">LOCK WASHERS, 1/2 11</title> <updated>2010-05-21T14:06:13-04:00</updated> <author> <name /> </author> <link rel="edit" title="PartsItem" href="Parts(12)" /> <category term="Microsoft.SharePoint.DataService.PartsItem" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" /> <content type="application/xml"> <m:properties> <d:Title>LOCK WASHERS, 1/2 11</d:Title> <d:SKU>SKU11</d:SKU> </m:properties> </content> </entry> </m:inline> </link> <category term="Microsoft.SharePoint.DataService.InventoryLocationsItem" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" /> <content type="application/xml"> <m:properties> <d:Title m:null="true" /> <d:PartId m:type="Edm.Int32">12</d:PartId> <d:BinNumber>Bin 0.5.17</d:BinNumber> <d:Quantity m:type="Edm.Double">9</d:Quantity> <d:Id m:type="Edm.Int32">18</d:Id> </m:properties> </content> </entry> </feed> --batchresponse_8ad6352b-ac02-4946-afc5-1df735bb7f55 Content-Type: application/http Content-Transfer-Encoding: binary HTTP/1.1 200 OK Cache-Control: no-cache DataServiceVersion: 2.0; Content-Type: application/atom+xml;charset=utf-8 <?xml version="1.0" encoding="utf-8" standalone="yes"?> <feed xml:base="http://contoso/sites/sharepointlist/_vti_bin/listdata.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"> <title type="text">Parts</title> <id>http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/Parts</id> <updated>2010-05-30T16:34:19Z</updated> <link rel="self" title="Parts" href="Parts" /> <entry m:ETag="W/&quot;2&quot;"> <id>http://contoso/sites/sharepointlist/_vti_bin/listdata.svc/Parts(12)</id> <title type="text">LOCK WASHERS, 1/2 11</title> <updated>2010-05-21T14:06:13-04:00</updated> <author> <name /> </author> <link rel="edit" title="PartsItem" href="Parts(12)" /> <category term="Microsoft.SharePoint.DataService.PartsItem" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" /> <content type="application/xml"> <m:properties> <d:Title>LOCK WASHERS, 1/2 11</d:Title> <d:SKU>SKU11</d:SKU> <d:Description m:null="true" /> <d:Id m:type="Edm.Int32">12</d:Id> </m:properties> </content> </entry> </feed> --batchresponse_8ad6352b-ac02-4946-afc5-1df735bb7f55--

Synchronous and Asynchronous Operations

The service proxy for the SharePoint REST interface supports synchronous and asynchronous calls to the service. The approach to managing asynchronous operations is almost identical to the CSOM experience. As described in the section, "Using the Service Proxy," earlier in this topic, the DataServiceQuery<TElement> class provides a BeginExecute method that you can use to asynchronously invoke a REST query. You should use the asynchronous approach in applications where you need to avoid blocking the UI thread. You cannot make a synchronous call to the REST interface from Silverlight or from JavaScript.