resourcetag
Topic Last Modified: 2006-06-12
A resourcetag is a token generated by the server that represents the state of a resource (depth=0). Microsoft® Exchange also provides support for the resourcetag Field on every replicated resource. The contents of the resourcetag are opaque to the client.
A resourcetag has the following properties:
- The client can fetch the resourcetag from the resourcetag Field on a resource.
- Two resourcetags are binary comparable by the client.
- The server guarantees that, if two resourcetags are the same when compared, the resource is the same.
- The client can include the resourcetag or repl-uid in the If Header of any WebDAV method request.
- The server returns the resourcetag of the resource as a response header for GET method, PUT method, POST method, MKCOL Method, PROPPATCH Method, and DELETE Method requests.
- The server returns the repl-uid of the resource as a response header for PUT method, POST method, MKCOL Method, and PROPPATCH Method requests.
It is recommended that the client store this property to reflect the state of the replicated resource. By storing the resourcetag Field, a WebDAV client can:
- Use the server-side conflict detection and resolution mechanism by sending its previously obtained resourcetag in the request headers of the GET method, PUT method, POST method, PROPFIND Method, PROPPATCH Method, MOVE Method, COPY Method, DELETE Method, and MKCOL Method requests.
- Use the resourcetag Field on a resource to detect if it has already obtained the latest version of a specific resource.
- Use the resourcetag Field on a resource to ensure consistency when it uploads or downloads data.
See the following scenarios for more information:
Client Uses Client-Side Conflict Detection