Logbook only returns the latest element

Question

When trying to use Datalogger and Logbook I only get the latest reading when querying the device Logbook when I expect to get an array of the readings saved.

I'm trying to build a 1-Wire reading app to test the platform, I have defined a subscription API very similar to /Meas/Temp:

paths:
  /OneWireTemp/Subscription:
    post:
      description: |
        Subscribe to periodic temperature readings.
      responses:
        200:
          description: Operation completed successfully
        x-std-errors:
          description: See common error codes http://developer.suunto.com/api/std-errors#subscribe
        x-notification:
          schema:
            $ref: "#/definitions/TempMeasurement"
    delete:
      description: |
        Unsubscribe to periodic temperature readings.
      responses:
        200:
          description: Operation completed successfully
        x-std-errors:
          description: See common error codes http://developer.suunto.com/api/std-errors#unsubscribe

definitions:
  TempMeasurement:
    required:
      - Timestamp
      - Measurement
    properties:
      Timestamp:
        description: Relative time of temperature reading
        type: integer
        format: uint32
        x-unit: millisecond
      Measurement:
        description: Temperature reading
        type: integer
        format: int16
        x-unit: celsius

I start the logging on device side with:

bool OneWireTempService::startDataLogger() {
  WB_RES::DataEntry entry;
  // Must match the subscription API path (without the /Subscription)
  entry.path = "/OneWireTemp";

  WB_RES::DataLoggerConfig dataLoggerConfig;
  WB_RES::DataEntry entries[] = {entry};
  dataLoggerConfig.dataEntries.dataEntry =
      wb::MakeArray<WB_RES::DataEntry>(entries, 1);

  wb::Result configureResult =
      asyncPut(WB_RES::LOCAL::MEM_DATALOGGER_CONFIG(),
               AsyncRequestOptions::Empty, dataLoggerConfig);

  if (!wb::RETURN_OK(configureResult)) {
    DebugLogger::error("Datalogger configuring failed: %u", configureResult);
    return false;
  }

  wb::Result stateResult = asyncPut(
      WB_RES::LOCAL::MEM_DATALOGGER_STATE(), AsyncRequestOptions::Empty,
      WB_RES::DataLoggerStateValues::Type::DATALOGGER_LOGGING);

  if (!wb::RETURN_OK(stateResult)) {
    DebugLogger::error("Datalogger enabling failed: %u", stateResult);
    return false;
  }

  return true;
}

and I update the subscription like this:

WB_RES::TempMeasurement tempMeasurement;
tempMeasurement.measurement = mTempReading;
tempMeasurement.timestamp = currentTime;

updateResource(WB_RES::LOCAL::ONEWIRETEMP(), ResponseOptions::Empty,
                tempMeasurement);

Now on Android side I connect to the device using MDS library and MDS/Logbook/{Serial}/Entries returns a log after a while: {"elements": [{"Id": 2, "ModificationTimestamp": 1613406975, "Size": null}]}.

When querying MDS/Logbook/{Serial}/ById/2/Data now I only get the latest measurement: {"OneWireTemp":{"Measurement":2536,"Timestamp":2794239193}}. The reading is not even in an array.

Answer 1

This was fixed by wrapping the result in an array, then the Datalogger seemed to understand that there can be multiple entries in the log:

paths:
  /OneWireTemp/Subscription:
    post:
      description: |
        Subscribe to periodic temperature readings.
      responses:
        200:
          description: Operation completed successfully
        x-std-errors:
          description: See common error codes http://developer.suunto.com/api/std-errors#subscribe
        x-notification:
          schema:
            $ref: "#/definitions/OneWireTempMeasurements"
    delete:
      description: |
        Unsubscribe to periodic temperature readings.
      responses:
        200:
          description: Operation completed successfully
        x-std-errors:
          description: See common error codes http://developer.suunto.com/api/std-errors#unsubscribe

definitions:
  OneWireTempMeasurements:
    required:
      - Measurements
    properties:
      Measurements:
        description: Wrapper array
        type: array
        items:
          $ref: '#/definitions/OneWireTempMeasurement'
  OneWireTempMeasurement:
    required:
      - Timestamp
      - Measurement
    properties:
      Timestamp:
        description: Relative time of temperature reading
        type: integer
        format: uint32
        x-unit: millisecond
      Measurement:
        description: Temperature reading in celsius
        type: integer
        format: int16
        x-unit: celsius