Driver documentation doesn't cover all mandatory functionality; should there be some function abstracting that?

[ericonr]

https://areadetector.github.io/areaDetector/ADCore/guidelines.html includes guidelines for developing drivers, but they are outdated/incomplete:

If NDArrayCallbacks is non-zero then drivers should do the following:

Call asynNDArrayDriver::getAttributes to attach any attributes defined for this driver to the current array.

Call doCallbacksGenericPointer() so that registered clients can get the values of the new arrays.

• It's missing the call to asynNDArrayDriver::updateTimestamps
• Is it missing anything else?

ADCore/ADApp/ADSrc/asynNDArrayDriver.cpp

Lines 832 to 836 in 84da957

	void asynNDArrayDriver::updateTimeStamps(NDArray *pArray)
	{
	updateTimeStamp(&pArray->epicsTS);
	pArray->timeStamp = pArray->epicsTS.secPastEpoch + pArray->epicsTS.nsec/1.e9;
	}

Even though it makes sense to document such requirements, is there a reason they can't be shared functionality? e.g. doCallbacksGenericPointer returns early if NDArrayCallbacks is false, or some prepareArray function exists which calls getAttributes and updateTimestamps and any other functions which are added to the required list.

[ericonr]

It's missing the call to asynNDArrayDriver::updateTimestamps

Some further code reading showed me that updateTimestamps might not cover all use cases; updateTimestamp(&pArray->epicsTS) is probably strictly necessary, and then pArray->timeStamp can support hardware specific timestamps if desired. I think this should be explained (and #537 should use updated documentation for this instead of simply converting the old HTML)