How to properly cascade attribute updates in self-referencial relationships and log all changes?

[kNicu]

I'm currently working on a very complicated project with many database-heavy operations and, most importantly, event listeners.

One such operation is logging every change of a model's attributes in before_update and adding that log to the database:

def log_awb_change(mapper, connection, target):
    from app import ignored_awb_fields
    user_id = None
    try:
        user_id = get_jwt_identity()
    except RuntimeError:
        print("Log awb change called outside app context")
        return
    
    if target.skip_log or target.id < 1:
        return
    logs = []
    
    from app.models.awb import AwbLog
    if not user_id:
        return
    state = inspect(target)
    for attr in state.attrs:
        if attr.key in ignored_awb_fields or not attr.history.has_changes():
            continue
        
        oldval = attr.history.deleted[0] if attr.history.deleted else None
        newval = attr.history.added[-1] if attr.history.added else None
        
        if oldval == newval:
            continue

        if attr.key in awb_files and (not oldval or not newval):
            if not oldval and newval:
                log = AwbLog(
                    awb_id=target.id,
                    text=f"fișierul {attr.key} a fost încărcat",
                    user_id = user_id
                )
                logs.append(log)
            elif oldval and not newval:
                log = AwbLog(
                    awb_id=target.id,
                    text=f"fișierul {attr.key} a fost șters",
                    user_id = user_id
                )
                logs.append(log)
            continue
        elif not isinstance(newval, list) and not type_inspect.isclass(newval) and not isinstance(newval, datetime) and not isinstance(newval, bool):
            text = ""
            if not oldval:
                text = f"{attr.key} a fost adăugat cu valoarea {newval}"
            elif not newval:
                text = f"{attr.key} a fost șters"
            elif oldval != newval:
                text = f"{attr.key} schimbat din {oldval} în {newval}" if attr.key not in awb_files else f"fișierul {attr.key} a fost schimbat"
            log = AwbLog(
                awb_id=target.id,
                text=text,
                user_id = user_id
            )
            logs.append(log)
        if attr.key == 'status':
            if newval == 'free from customs':
                from app.admin.borderou import add_to_borderou
                from app.admin.message import fn_send_free_from_customs
                add_to_borderou(target, type='bord-out')
                fn_send_free_from_customs(target, user_id, db.session)
        
    db.session.bulk_save_objects(logs)

Now, this all worked fine before needing another change, which is associating multiple objects to one, basically creating a sort of "hierarchy", where if one object's attribute changes, so does the same attribute for all objects in the hierarchy, keeping them all identical.

I have tried to make a function that would do this very thing, but it's causing a lot of unexpected issues and it's making me go back to the drawing board, because I have no idea what the best approach would be to update all attributes for the members in the hierarchy.

The desired result would be something like: member updates -> updates all members -> log change for current member -> log change for all members -> save the changes to the db.

Below is the aforementioned function:

def update_hierarchy(target):
    # if target.skip_check:
    #     return
    hierarchy = target.get_hierarchy()
    if not hierarchy:
        return
    print(f"\nUpdate hierarchy called for awb {target.nr}")
    
    val_fields = [
        'status', 'declarant_id', 'operator_id', 'paid_status', 'curr', 'invoice_status_string', 'h_value', 'h7_value',
        'invoice_read_date', 'declarant_changed_date', 'operator_changed_date', 'recipient_name', 'recipient_street',
        'recipient_street_cont', 'recipient_zip', 'recipient_state', 'recipient_country', 'recipient_email', 'recipient_city',
        'sale', 'tax', 'postage', 'cds_postage', 'person_type', 'cif', 'company', 'payment_type'
    ]
    from sqlalchemy.orm.attributes import flag_modified
    for child in hierarchy:
        for field in val_fields:
            newval = getattr(target, field)
            if getattr(child, field) != newval:
                continue
            # print(f"Changing attr {field} for {child.nr} from {getattr(child, field)} to {newval}")
            # child.skip_check = True
            setattr(child, field, newval)

Weirdly enough, setattr didn't seem to update the value of any member, but assigning the value straight up like child.status = target.status seemed to track those changes.

What would be the best approach to logging the changes and updating the hierarchy while still causing as little flushes?