如何从SAP Cloud SDK中的JavaScript的DocumentInfoRecord get（）调用中获取eTag（MetaData）？

Question

I use the SAP Cloud SDK for javascript to handle DocumentInfoRecords. An update of a DIR caused the error 428. So I need the etag of the request like in the SAP Cloud API.

How can I get the etag from the GET request or generally header response information of each sdk request?

GET:

DocumentInfoRecord.requestBuilder()
.getByKey(dir.documentInfoRecordDocType, dir.documentInfoRecordDocVersion, dir.documentInfoRecordDocNumber, dir.documentInfoRecordDocPart)
.execute({});

UPDATE with etag

DocumentInfoRecord.requestBuilder().update(dir).withCustomHeaders({ key: "If-Match", value: "etag" }).execute({});

Answer 1

UPDATE: Please see the answer of Henning Heitkötter.

---

Currently we do not support eTag handling. We are aware of this shortcoming and already have it in our backlog. We will update this answer as soon as the feature is available.

Answer 2

Since version 1.1.0, the SAP Cloud SDK for JavaScript (fka SAP S/4HANA Cloud SDK) transparently handles ETag in the background. For more information, take a look at the section on optimistic concurrency control in the release blog .

If you update to the latest version (1.2.1 at the time of writing), you can simply retrieve the document info record, change the fields you want to change, and then update it by sending the same object to the service.

var dir = await DocumentInfoRecord.requestBuilder()
    .getByKey(dir.documentInfoRecordDocType, dir.documentInfoRecordDocVersion, dir.documentInfoRecordDocNumber, dir.documentInfoRecordDocPart)
    .execute({destinationName: "MyServer"});
dir.responsiblePersonName = "John Doe";
DocumentInfoRecord.requestBuilder()
    .update(dir)
    .execute({destinationName: "MyServer"})
    .then(...);