Showing unsaved status for document-based windows

[Ian Wood]

On 12 Jan 2008, at 21:56, Randall Lee Reetz wrote:

> Maybe a better question is: why does the document "need to be  
> saved"?  Why isnt it saved as it is being changed?  Should the user  
> have to be aware of the memory/hard disc schism?  Just a thought.


Re-written because it was turning into a nasty rant and I don't think  
you *meant* to irritate me...

The saved/unsaved document concept is immediately familiar to almost  
ALL computer users. As the app I'm working on is based around building  
visual flowcharts to automate photographic workflows I need to keep  
the rest of the app as familiar as possible. The app itself introduces  
enough new concepts for people who aren't used to thinking in those  
ways - we photographers are renowned for not thinking in programming  
terms. ;-)

There are also issues of ease of coding, reliability and speed.
A routine which grabs info about all the flowchart steps, converts it  
to XML and writes to file  is pretty easy to write, and the user isn't  
expecting the app to do anything else at the time so it doesn't matter  
if it takes a moment.
If the flowchart gets sufficiently large and complex that the routine  
starts impacting noticeably on the end user by being called too often  
you then need to start breaking down the saving routines to only  
handle what has changed, a *vastly* more complex affair. And, as  
always, complex code tends to mean buggier code.

Next - have you tried implementing a fully-functional and totally  
reliable undo mechanism in Rev? Doable, but not particularly easy. So  
what does your user do when they make a mistake and delete a vast  
swathe of their flowchart? They open up the previously-saved version.  
With constantly-updating files this is no longer possible.
Further issues arise when people want to make a new doc from an  
existing one - they immediately look for a Save As... command, in  
which case they are already conditioned to expect a Save command just  
above it.
Potentially you are looking at building a versioning system, which is  
total overkill.


Obviously there are areas where it works, like iCal, iTunes etc. but  
they aren't really what I'd regard as document-based apps. You don't  
generally have a few dozen different calendars or music libraries you  
open and close and choose between. The apparently document-based apps  
that work in this way, such as Aperture and Lightroom were full of  
people in the early days asking 'but how do I save it?'.

So, a nice enough thought, but but waaaay off-topic for my needs.

Ian