make use of gathered attribute in ALDocumentBundle

[nonprofittechy]

Possibly fix #806, fix #889

I don't precisely remember why we didn't do that already--I think overly cautious about potential side effects when using ALDocument.

Opening as draft because it seems like a fundamental change that needs careful testing. But I don't see why it wouldn't solve what we want it to solve.

[plocket]

Possibly fix #806, fix #889

It looks like #806 was already fixed. Did you mean a different issue?

Regarding the change, it seems like this may change the behavior of existing interviews depending on what architecture folks have set up. Are their arrangements of code that would break if docassemble tried to enforce a traditional gather loop?

[nonprofittechy]

Regarding the change, it seems like this may change the behavior of existing interviews depending on what architecture folks have set up. Are their arrangements of code that would break if docassemble tried to enforce a traditional gather loop?

Well, that's what I'm looking for some feedback on. That's the risk I'm talking about above.

We're not talking here about a traditional gather loop--just seeking the .gathered attribute if gathered=False at initialization time of the bundle, which should look for a code block that has the definitive set of rules about how many documents to add to the bundle.

I think the most helpful thing would be to identify specific test cases to validate the behavior change is safe. The high level goal (confirming defining gathered in a separate code block won't have side effects) is clear.