RapidPro: Add support to remove from all groups if left blank

[geoo89]

If the main argument ("message_text") is left blank in a remove_from_group row, the user will be removed from all groups.

fixes #161

[fagiothree]

I see how this is the most "elegant" way to implement it (also considering the json has an empty list for groups), but I wondering if this is maybe a bit dangerous from an authoring perspective? Could we maybe have a warning?

[geoo89]

I added a warning, please check.

We could also consider adding a special keyword like ALL (in all caps) that will also remove from all groups, but suppress the warning (in addition or instead of leaving the cell blank).

[fagiothree]

@geoo89 the code did run fine and created the node as expected. The warning is included in the logs, but I am wondering if maybe it should also be in the terminal?
Happy also to have "ALL" and suppress the warning in that case, if that's easy to implement

[geoo89]

If I remember, warnings are by design only written to the log, while critical errors stop execution (and show an error in the terminal). There is the error level in between, does that have the behavior you propose? (Do you know of any errors that are shown in the terminal but do not stop execution?)

[fagiothree]

mm yeah, you are right, I don't think there are. So maybe the safest would be to have the "ALL" keyword?

[geoo89]

Ok, I'll implement that then.
Should I elevate the blank cell to an error then and require the ALL? Only downside would be if you happen to have a group named "ALL".

[geoo89]

I added support for the ALL keyword, while leaving the warning in case the cell is empty.