null #16
Description
This started in the now-closed disarm-platform/algorithms-issues#8
Think is more an issue for documentation.
Original issue was:
This is another of the more general issues, this time about handling missing or empty values: null, nil, None, NA, undefined, NULL, and so on. They're different in different languages, and have different implications for different use cases. (This issue was triggered by discussion on disarm-platform/ui-raster-vector-summary-stats#1)
As we're using JSON for the interchange, might be worth focusing on how this concept is handled in there. The spec is quite useful, and short story is that besides a values (string, number, boolean, array or objects), the only other value that can be represented is null - e.g. {"value": null}. So if we're handling that correctly on the function and UI sides, we should be ok.
It's possible that our functions are returning {"value": "null"} (a string of the word 'null' rather than the value null), or something similar - but that is probably a bug and we should address it in the function, rather than handling in the UI.
Would be great to hear from esp @HughSt and @ric70x7 about what problems we might run into if we're limiting ourselves to only using null.