[GNC] mysql backend, second user (lock, for example)

[Geert Janssens]

Op zondag 4 november 2018 14:49:22 CET schreef craigarno:
> Geert Janssens-4 wrote
> 
> > Op zondag 4 november 2018 04:36:30 CET schreef craigarno:
> > The only part I have no idea about at this stage is how to tell all views
> > to refresh when one user makes a change.
> 
> If you are headed toward C++, the "Observer" Design Pattern may be able to
> get the "refresh views" job done for you.
> 
> Where observer pattern is used?
> Observer pattern is used when there is one-to-many relationship between
> objects such as if one object is modified, its dependent objects are to be
> notified automatically. Observer pattern falls under behavioral pattern
> category.

Thanks for naming it. The concept is good. Whether it can work depends on 
whether the db layer we rely on has a notification mechanism for db changes we 
can hook into. The current db layer is provided by libdbi, which is not 
managed by the gnucash team and I haven't looked into this yet. That's where 
my "I have no idea" came from :)

Geert