Describes Windows 7 support for search federation to remote data stores using OpenSearch technologies that enable users to access and interact with their remote data from within Windows Explorer.

This topic is organized as follows:

• What is Federated Search?
• Steps for Building Federated Search
• How Federated Search Works
• Sending Queries and Returning Search Results in RSS or Atom
• Additional Resources
• Related Topics

What is Federated Search?

Windows 7 supports the connection of external sources to the Windows Client through the OpenSearch  protocol. This enables users to search a remote data store and view results from within Windows Explorer. The OpenSearch v1.1 standard defines simple file formats that can be used to describe how a client should query the Web service for the data store and how the service should return results to be rendered by the client. Windows federated search connects to Web services that receive OpenSearch queries, and returns results in either the RSS or Atom XML format.

The following screenshot illustrates the search results obtained after remotely searching a Sharepoint.

Steps for Building Federated Search

To build federated search, perform the following steps:

1. Enable your data store to be searched from Windows Explorer by providing an OpenSearch-compatible Web service that can return results in RSS or Atom format.
2. Create an OpenSearch Description (.osdx) file that describes how to connect to the Web service and how to map any custom elements in your RSS or Atom XML.
3. Deploy the search connectors to Windows client computers with an .osdx file.

The following diagram illustrates the steps for building federated search.

How Federated Search Works

Communication between Windows Explorer and your OpenSearch Web service is performed through the Windows Data Layer. The Windows Data Layer can communicate with different types of data stores through Windows Store Providers. Each provider specializes in communicating with data stores that support a particular protocol and have specific capabilities. The OpenSearch provider communicates with data stores that provide a Web service that supports the OpenSearch standard.

To enable your data store to support federated search in Windows 7, you must perform a number of tasks. The following table lists tasks for enabling your data store, what is required to accomplish each task, and where to find documentation.

Sending Queries and Returning Search Results in RSS or Atom

When the user types a term into the search box in the upper-right corner of Windows Explorer, the query is sent to the OpenSearch provider, which then sends the query to the remote data store. The remote Web service responds to the query by providing results in an XML document, typically referred to as a feed, in one of two supported formats (RSS or Atom). Each result item in the feed includes XML child elements to represent or describe item metadata, such as the title, URL, description, thumbnail picture, and so forth. The OpenSearch provider is responsible for mapping the XML element values to Windows Shell system properties that can be used by Windows applications.

Additional Resources

• The OpenSearch code sample, available on Code Gallery and the Windows 7 SDK, demonstrates how to create a federated search service using the OpenSearch protocol, and an OpenSearch Descriptor (.osdx) file (a search connector).
• For a video demonstration of creating an OpenSearch Web service for a SQL database, see Windows 7: Empower Users to Find, Visualize and Organize their Data with Libraries and the Explorer .
• If you are writing a client-side OpenSearch provider, see:
  • The OpenSearch Developer How To Guide  for more information on connecting to a client-side provider by using a proprietary data store's protocols or APIs.
  • The Overview of the Search Connector Description Schema (.searchconnector-ms) schema documentation.
• See the Microsoft Download Center Web site for the following downloadable resource: Search Server 2008 Sample: Federated Search Connector Sample.

Related Topics

• Connecting Your Web Service in Windows Federated Search
• Enabling Your Data Store in Windows Federated Search
• Creating an OpenSearch Description File in Windows Federated Search
• Following Best Practices in Windows Federated Search
• Deploying Search Connectors in Windows Federated Search