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    Changes API: How to Subscribe to Counter Changes

    Following methods allow you to subscribe to counter changes:

    ForCounter

    Counter changes can be observed using forCounter method. This will subscribe changes from all counters with a given name, no matter in what document counter was changed.

    Syntax

    IChangesObservable<CounterChange> forCounter(String counterName);
    Parameters
    counterName String Name of a counter to subscribe to.
    Return Value
    IChangesObservable<CounterChange> Observable that allows to add subscriptions to counter notifications.

    Example

    store
    .changes()
    .forCounter("likes")
    .subscribe(Observers.create(change -> {
        switch (change.getType()) {
            case INCREMENT:
                // do something ...
                break;
        }
    }));

    ForCounterOfDocument

    Specific counter changes of a given document can be observed using forCounterOfDocument method.

    Syntax

    IChangesObservable<CounterChange> forCounterOfDocument(String documentId, String counterName);
    Parameters
    documentId String ID of a document to subscribe to.
    counterName String Name of a counter to subscribe to.
    Return Value
    IChangesObservable<CounterChange> Observable that allows to add subscriptions to counter notifications.

    Example

    store
    .changes()
    .forCounterOfDocument("companies/1-A", "likes")
    .subscribe(Observers.create(change -> {
        switch (change.getType()) {
            case INCREMENT:
                // do something
                break;
        }
    }));

    ForCountersOfDocument

    Counter changes of a specified document can be observed using forCountersOfDocument method.

    Syntax

    IChangesObservable<CounterChange> forCountersOfDocument(String documentId);
    Parameters
    documentId String ID of a document to subscribe to.
    Return Value
    IChangesObservable<CounterChange> Observable that allows to add subscriptions to counter notifications.

    Example

    store
    .changes()
    .forCountersOfDocument("companies/1-A")
    .subscribe(Observers.create(change -> {
        switch (change.getType()) {
            case INCREMENT:
                // do something ...
                break;
        }
    }));

    ForAllCounters

    Changes for all counters can be observed using forAllCounters method.

    Syntax

    IChangesObservable<CounterChange> ForAllCounters();
    Return Value
    IChangesObservable<CounterChange> Observable that allows to add subscriptions to counter notifications.

    Example

    store
    .changes()
    .forAllCounters()
    .subscribe(Observers.create(change -> {
        switch (change.getType()) {
            case INCREMENT:
                // do something ...
                break;
        }
    }));

    CounterChange

    Name Type Description
    Type CounterChangeTypes Counter change type enum
    Name String Counter name
    Value Long Counter value after the change
    DocumentId String Counter document identifier
    ChangeVector String Counter's ChangeVector

    CounterChangeTypes

    Name Value
    NONE 0
    PUT 1
    DELETE 2
    INCREMENT 4

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