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Changes API: How to subscribe to document changes?

Following methods allow you to subscribe to document changes:

ForDocument​

Single document changes can be observed using ForDocument method.

Syntax​

IChangesObservable<DocumentChange> ForDocument(string docId);
Parameters
docIdstringId of a document for which notifications will be processed.
Return Value
IObservableWithTask<DocumentChangeNotification>Observable that allows to add subscriptions to notifications for given document.

Example​

IDisposable subscription = store
  .Changes()
  .ForDocument("employees/1")
  .Subscribe(
      change =>
      {
          switch (change.Type)
          {
              case DocumentChangeTypes.Put:
                  // do something
                  break;
              case DocumentChangeTypes.Delete:
                  // do something
                  break;
          }
      });

ForDocumentsInCollection​

To observe all document changes in particular collection use ForDocumentInCollection method. This method filters documents by Raven-Entity-Name metadata property value.

Syntax​

IChangesObservable<DocumentChange> ForDocumentsInCollection(string collectionName);

IChangesObservable<DocumentChange> ForDocumentsInCollection<TEntity>();
Parameters
collectionNamestringName of document collection for which notifications will be processed.
Return Value
IObservableWithTask<DocumentChangeNotification>Observable that allows to add subscriptions to notifications for given document collection name.

Overload with TEntity type uses Conventions.GetTypeTagName to get collection name.

Example​

IDisposable subscription = store
  .Changes()
  .ForDocumentsInCollection<Employee>()
  .Subscribe(change => Console.WriteLine("{0} on document {1}", change.Type, change.Id));

or

string collectionName = store.Conventions.FindCollectionName(typeof(Employee));
IDisposable subscription = store
  .Changes()
  .ForDocumentsInCollection(collectionName)
  .Subscribe(change => Console.WriteLine("{0} on document {1}", change.Type, change.Id));

ForDocumentsOfType​

To observe all document changes for given type use ForDocumentsOfType method. This method filters documents by Raven-Clr-Type metadata property value.

Syntax​

IObservableWithTask<DocumentChangeNotification>
ForDocumentsOfType(string typeName);

IObservableWithTask<DocumentChangeNotification>
ForDocumentsOfType(Type type);

IObservableWithTask<DocumentChangeNotification>
ForDocumentsOfType<TEntity>();
Parameters
typeName or typestring or TypeName of type or type for which notifications will be processed. If default conventions are used, the full type name without version information should be passed. See Raven.Client.Document.ReflectionUtil.GetFullNameWithoutVersionInformation.
Return Value
IObservableWithTask<DocumentChangeNotification>Observable that allows to add subscriptions to notifications for given document type name.

Overloads with TEntity type or Type uses Conventions.FindClrTypeName to get type name.

Example​

IDisposable subscription = store
.Changes()
.ForDocumentsOfType<Employee>()
.Subscribe(change => Console.WriteLine("{0} on document {1}", change.Type, change.Id));

or

string typeName = store.Conventions.FindClrTypeName(typeof(Employee));
IDisposable subscription = store
.Changes()
.ForDocumentsOfType(typeName)
.Subscribe(change => Console.WriteLine("{0} on document {1}", change.Type, change.Id));

ForDocumentsStartingWith​

To observe all document changes for documents with Id that contains given prefix use ForDocumentsStartingWith method.

Syntax​

IChangesObservable<DocumentChange> ForDocumentsStartingWith(string docIdPrefix);
Parameters
docIdPrefixstringDocument Id prefix for which notifications will be processed.
Return Value
IObservableWithTask<DocumentChangeNotification>Observable that allows to add subscriptions to notifications for given document Id prefix.

Example​

IDisposable subscription = store
  .Changes()
  .ForDocumentsStartingWith("employees/1") // employees/1, employees/10, employees/11, etc.
  .Subscribe(change => Console.WriteLine("{0} on document {1}", change.Type, change.Id));

ForAllDocuments​

To observe all document changes use ForAllDocuments method.

Syntax​

IChangesObservable<DocumentChange> ForAllDocuments();
Return Value
IObservableWithTask<DocumentChangeNotification>Observable that allows to add subscriptions to notifications for all documents.

Example​

IDisposable subscription = store
  .Changes()
  .ForAllDocuments() // employees/1, orders/1, customers/1, etc.
  .Subscribe(change => Console.WriteLine("{0} on document {1}", change.Type, change.Id));

Remarks​

To get more method overloads, especially the ones supporting delegates, please add Reactive Extensions package to your project.