Changes API: How to Subscribe to Index Changes

Following methods allow you to subscribe to index changes:

• ForIndex
• ForAllIndexes

ForIndex

Index changes for one index can be observed using ForIndex method.

Syntax

IChangesObservable<IndexChange> ForIndex(string indexName);

Parameters
indexName	string	Name of an index for which notifications will be processed.

Return value
IChangesObservable<IndexChange>	Observable that allows to add subscriptions to notifications for index with given name.

Example

IDisposable subscription = store
  .Changes()
  .ForIndex("Orders/All")
  .Subscribe(
      change =>
      {
          switch (change.Type)
          {
              case IndexChangeTypes.None:
                  //Do someting
                  break;
              case IndexChangeTypes.BatchCompleted:
                  //Do someting
                  break;
              case IndexChangeTypes.IndexAdded:
                  //Do someting
                  break;
              case IndexChangeTypes.IndexRemoved:
                  //Do someting
                  break;
              case IndexChangeTypes.IndexDemotedToIdle:
                  //Do someting
                  break;
              case IndexChangeTypes.IndexPromotedFromIdle:
                  //Do someting
                  break;
              case IndexChangeTypes.IndexDemotedToDisabled:
                  //Do someting
                  break;
              case IndexChangeTypes.IndexMarkedAsErrored:
                  //Do someting
                  break;
              case IndexChangeTypes.SideBySideReplace:
                  //Do someting
                  break;
              case IndexChangeTypes.IndexPaused:
                  //Do someting
                  break;
              case IndexChangeTypes.LockModeChanged:
                  //Do someting
                  break;
              case IndexChangeTypes.PriorityChanged:
                  //Do someting
                  break;
              default:
                  throw new ArgumentOutOfRangeException();
          }
      });

ForAllIndexes

Index changes for all indexex can be observed using ForAllIndexes method.

Return value
IChangesObservable<IndexChange>	Observable that allows to add subscriptions to notifications for all indexes.

Syntax

IChangesObservable<IndexChange> ForAllIndexes();

Example

IDisposable subscription = store
  .Changes()
  .ForAllIndexes()
  .Subscribe(change => Console.WriteLine("{0} on index {1}", change.Type, change.Name));

IndexChange

Properties

Name	Type	Description
Type	IndexChangeTypes	Change type
Name	string	Index name
Etag	long?	Index Etag

IndexChangeTypes

Name	Value
None	0
BatchCompleted	1
IndexAdded	8
IndexRemoved	16
IndexDemotedToIdle	32
IndexPromotedFromIdle	64
IndexDemotedToDisabled	256
IndexMarkedAsErrored	512
SideBySideReplace	1024
IndexPaused	4096
LockModeChanged	8192
PriorityChanged	16384

Remarks

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