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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

    store.changes().forDocument(docId);
    Parameters
    docId string ID of a document for which notifications will be processed.
    Return Value
    IChangesObservable<DocumentChange> Observable that allows to add listeners for events for given document.

    Example

    store.changes().forDocument("employees/1")
    .on("error", err => {
        //handle error 
    })
    .on("data", change => {
        switch (change.type) {
            case "Put":
                // do something
                break;
            case "Delete":
                // do something
                break;
        }
    });

    forDocumentsInCollection

    To observe all document changes in particular collection use forDocumentInCollection() method. This method filters documents by @collection metadata property value.

    Syntax

    store.changes().forDocumentsInCollection(collectionName);
store.changes().forDocumentsInCollection(clazz);
    Parameters
    collectionName string Name of document collection for which notifications will be processed.
    Return Value
    IChangesObservable<DocumentChange> Observable that allows to add subscriptions to notifications for given document collection name.

    Information

    Overload with entity type uses conventions.getCollectionNameForType() to get collection name.

    Example

    store.changes().forDocumentsInCollection(Employee)
    .on("data", change => {
        console.log(change.type + " on document " + change.id);
    });

    or

    const collectionName = store.conventions.getCollectionNameForType(Employee);
store.changes()
    .forDocumentsInCollection(collectionName)
    .on("data", change => {
        console.log(change.type + " on document " + change.id);
    });

    forDocumentsStartingWith

    To observe all document changes for documents with ID that contains given prefix use forDocumentsStartingWith() method.

    Syntax

    store.changes().forDocumentsStartingWith(docIdPrefix);
    Parameters
    docIdPrefix string Document ID prefix for which notifications will be processed.
    Return Value
    IChangesObservable<DocumentChange> Observable that allows to add subscriptions to notifications for given document ID prefix.

    Example

    store.changes()
    .forDocumentsStartingWith("employees/1") // employees/1, employees/10, employees/11, etc.
    .on("data", change => {
        console.log(change.type + " on document " + change.id);
    });

    forAllDocuments

    To observe all document changes use forAllDocuments() method.

    Syntax

    store.changes().forAllDocuments();
    Return Value
    IChangesObservable<DocumentChange> Observable that allows to add subscriptions to notifications for all documents.

    Example

    store.changes().forAllDocuments()
    .on("data", change => {
        console.log(change.type + " on document " + change.id);
    });

    DocumentChange

    Name Type Description
    type DocumentChangeTypes Document change type enum
    id string Document identifier
    collectionName string Document's collection name
    typeName string Type name
    changeVector string Document's ChangeVector

    DocumentChangeTypes

    Name
    None
    Put
    Delete
    BulkInsertStarted
    BulkInsertEnded
    BulkInsertError
    DeleteOnTombstoneReplication
    Conflict
    Common

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    Changes API

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