Why re-generate a locked file!?

[Chafik Graiguer]

Here is the scenario:
working with file farabi.fet, I generated timetable, lock it then save it
Next, I save it under new filename: farabi2.fet
Reopen farabi.fet, trying ot view teachers timetable
FET ask me to generate first.
But the file is locked !! why sould we re-generate it !?

Now suppose, I locked the file, changed same constraints, try to regenerate
Obviousely, generation may fail, because new constraints are not compatible with locked slots
First, user has to unlock file, but it is asked to re-generate first
That is why I usualy unlock the file before changing constraints unless  I forget to do so

[Volker Dirr]

Here is the scenario:
working with file farabi.fet, I generated timetable, lock it then save it
Next, I save it under new filename: farabi2.fet
Reopen farabi.fet, trying ot view teachers timetable
FET ask me to generate first.
But the file is locked !! why sould we re-generate it !?

Difficult to explain. I will try, maybe Liviu can explain better.

Locking mean only "adding (many) time and space constraints" (activity preferred time and space).

Generating mean it try to solve the dataset and write the results a timetable (that (also) mean store result in a special memory place.)

so if you load a "locked" dataset, then you just has loaded all that constraint. of course we know it is solveable, but the timetable is not written to that special memory place. if you generate now, it write results at that special memory place. (a second nice thing is, that it recheck the dataset. so we can be more sure the algorithm is working correct.)

Now suppose, I locked the file, changed same constraints, try to regenerate
Obviousely, generation may fail, because new constraints are not compatible with locked slots
First, user has to unlock file, but it is asked to re-generate first
That is why I usualy unlock the file before changing constraints unless  I forget to do so

yes, that is a small problem. i also remember that beaviour some time ago, but we thought it is not critical.
currently your workaround is correct. generate and unlock before you change constraints.

i will have a look if we can unlock even without generating. that should be possible. but please wait a bit, i am currently busy.

[Chafik Graiguer]

Thanks for reply

Generating mean it try to solve the dataset and write the results a timetable (that (also) mean store result in a special memory place.

IS it possible to instruct FET  to test if the opened file is locked, if so, write it  into that memory place so user can view timetables without need to regenerate.
If the user has changed something in constraints after locking the file, FET can show a warning window before displaying timetables