Changes API: How to Subscribe to Time Series Changes

C#

• Use the following methods to subscribe to Time Series Changes:
  • ForTimeSeries
    Track all time series with a given name
  • ForTimeSeriesOfDocument
    Overload #1: Track a specific time series of a chosen document
    Overload #2: Track any time series of a chosen document
  • ForAllTimeSeries
    Track all time series

The Subscribe method on the observable these methods return accepts only an IObserver object by default.
To instead subscribe with a delegate, like the change => ... lambda used in the examples below, add the System.Reactive package to your project.
This adds Subscribe overloads that take delegates, including ones with error and completion handlers.

• In this article:
  • ForTimeSeries
  • ForTimeSeriesOfDocument
  • ForAllTimeSeries
  • TimeSeriesChange and TimeSeriesChangeTypes syntax

ForTimeSeries

Subscribe to changes in all time series with a given name, no matter which document they belong to, using the ForTimeSeries method.

Syntax

IChangesObservable<TimeSeriesChange> ForTimeSeries(string timeSeriesName);

Parameters
timeSeriesName	string	Name of a time series to subscribe to.

Return Value
IChangesObservable<TimeSeriesChange>	Observable that allows to add subscriptions to time series notifications.

Example

IDisposable subscription = store
    .Changes()
    .ForTimeSeries("Likes")
    .Subscribe
        (change =>
        {
            switch (change.Type)
            {
                case TimeSeriesChangeTypes.Delete:
                    // do something
                break;
            }
        });

ForTimeSeriesOfDocument

Use ForTimeSeriesOfDocument to subscribe to changes in time series of a chosen document.

• Two overload methods allow you to
  • Track a specific time series of the chosen document
  • Track any time series of the chosen document

Overload #1

Use this ForTimeSeriesOfDocument overload to track changes in a specific time series of the chosen document.

Syntax

IChangesObservable<TimeSeriesChange> ForTimeSeriesOfDocument(string documentId, string timeSeriesName);

Parameters
documentId	string	ID of a document to subscribe to.
timeSeriesName	string	Name of a time series to subscribe to.

Return Value
IChangesObservable<TimeSeriesChange>	Observable that allows to add subscriptions to time series notifications.

Example

IDisposable subscription = store
    .Changes()
    .ForTimeSeriesOfDocument("companies/1-A", "Likes")
    .Subscribe
        (change =>
        {
            switch (change.Type)
            {
                case TimeSeriesChangeTypes.Delete:
                    // do something
                break;
            }
        });

Overload #2

Use this ForTimeSeriesOfDocument overload to track changes in any time series of the chosen document.

Syntax

IChangesObservable<TimeSeriesChange> ForTimeSeriesOfDocument(string documentId);

Parameters
documentId	string	ID of a document to subscribe to.

Return Value
IChangesObservable<TimeSeriesChange>	Observable that allows to add subscriptions to time series notifications.

Example

IDisposable subscription = store
    .Changes()
    .ForTimeSeriesOfDocument("companies/1-A")
    .Subscribe
        (change =>
        {
            switch (change.Type)
            {
                case TimeSeriesChangeTypes.Delete:
                    // do something
                break;
            }
        });

ForAllTimeSeries

Subscribe to changes in all time series using the ForAllTimeSeries method.

Syntax

IChangesObservable<TimeSeriesChange> ForAllTimeSeries();

Return Value
IChangesObservable<TimeSeriesChange>	Observable that allows to add subscriptions to time series notifications.

Example

IDisposable subscription = store
    .Changes()
    .ForAllTimeSeries()
    .Subscribe
        (change =>
        {
            switch (change.Type)
            {
                case TimeSeriesChangeTypes.Delete:
                    // do something
                break;
            }
        });

TimeSeriesChange and TimeSeriesChangeTypes syntax

• TimeSeriesChange
• TimeSeriesChangeTypes

The notification object delivered to subscribers when a time series changes.

class TimeSeriesChange
{
    TimeSeriesChangeTypes Type
    string Name
    string DocumentId
    string CollectionName
    DateTime From
    DateTime To
    string ChangeVector
}

Property	Type	Description
Type	TimeSeriesChangeTypes	Time series change type enum
Name	string	Time Series Name
DocumentId	string	Time series Document Identifier
CollectionName	string	Time series document Collection Name
From	DateTime	Time series values From date
To	DateTime	Time series values To date
ChangeVector	string	Time series Change Vector

enum TimeSeriesChangeTypes
{
    None,
    Put,
    Delete,
    Mixed,
}

Name	Value
None	0
Put	1
Delete	2
Mixed	3