Ingest Result Handlers

When you ingest a document using the Add, Replace, Remove or Update methods, the ingest command is placed in a queue and the method returns immediately. ConnectorLib C++ takes care of batching, sending the commands, and dealing with any transitory problems communicating with the target.

As a result, the Add, Replace, Remove and Update methods never fail, even if there is a problem ingesting a document. To find out whether each document was ingested successfully, you can register an Ingest result handler:

       MyIngestResultHandler handler(task.log());
       task.ingester().addResultHandler(handler);

The class MyIngestResultHandler is a user defined function object. In this example it is constructed with a Log.

The result handler is called whenever a document is successfully ingested or when ingestion fails for a document. A simple result handler is shown here:

class MyIngestResultHandler : public Ingester::ResultHandler
{
    Log m_log;

public:
    MyIngestResultHandler(const Log& log)
      : m_log(log)
    {}

    void operator()(const IngestTask& ingestTask)
    {
        if (ingestTask.status() == IngestTaskStatus::Done)
        {
            m_log.full("Document " + ingestTask.document().reference()
                + ", ingest " + ingestTask.typeString() + " succeeded!");
        }
        else
        {
            m_log.full("Ingestion failed for " + ingestTask.document().reference());
        }
    }
};

Ingest result handlers are useful when you want to update state information only when documents are ingested successfully. An example of a connector using an ingest result handler for this purpose is included in Make an Incremental Synchronize Action.