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1. 

   NickDMax
   Member

   Just a warning - I think this was caused by a PYPN script error:

   I just did an undo that reset my file to a state from 2 days ago and caused me to loose a large block of (tested) programming. Of course as Murphy would have it this code was particularly painful to develop the first time and is turning out to be a pain to recreate.

   I don't have time at the moment to really investigate the cause but I *think* it may be caused by a PYPN script beginning an undo action and then not ending it.

   What confuses me is I though that once you save a file you can't undo back before that point -- but in the newer version I guess you can. So just a warning to look over your file before you save! Close and reopen the file every now and then. Be careful with you code! :(

   Posted 2 years ago #
2. 

   simon
   PN Developer

   Hi Nick, really sorry to hear this - that sucks.

   I was thinking about the undo collection thing and it seems that most scripts use this pattern:

   @script()
   def MyScript():
       sci.BeginUndoCollection()
       sci.Stuff()
       sci.MoreStuff()
       sci.EndUndoCollection()

   If anything goes wrong in the middle there then we'll leave a broken undo collection which is obviously undesirable, and may cause serious issues it seems. I think we could probably make the script attribute do something smart here like this:

   @script(undo_group = True)
   def MyScript():
       sci.Stuff()
       sci.MoreStuff()

   This could then cause the whole function to be wrapped in a try/finally group so that when run the script would effectively be:

   try:
       sci.BeginUndoCollection()
       sci.Stuff()
       sci.MoreStuff()
    finally:
       sci.EndUndoCollection()

   In fact, I wonder if this behaviour defaulting to on would be best?

   Posted 2 years ago #
3. 

   simon
   PN Developer

   To address the point about undoing before a save, I could have sworn that was an option in PN 2 but must be wrong, it was definitely there in PN 1. If you'd like to have it back please raise an enhancement issue.

   You can use PyPN to do this for yourself:

   oldOnSaved = glue.onDocSaved
   def KillUndoOnSaved(doc):
   	oldOnSaved(filename, doc)
   	s = scintilla.Scintilla(doc)
   	s.EmptyUndoBuffer()
   
   glue.onDocSaved = KillUndoOnSaved

   Place this in a .py file in your scripts directory and you should see the undo being cleared on every save. I need to come up with a better solution for handling these events so you don't need to handle chaining in each script, but it's a start.

   Posted 2 years ago #
4. 

   NickDMax
   Member

   That is pretty awesome. I am torn about this though because while loosing a few days works really sucks, being able to make a change, save compile, and then undo that change when it causes trouble is nice. Though the glue script does give me an idea for a light weight version control system -- just something to maintain a small cache of backups. It would be neat to be able to integrate that with the idea of a project.

   Anyway thanks for taking some time to think about my pain :). I think the PyPN undo_group is an excellent idea. glue is really a neat module and I hope that when you update PyPN you expand glue with more actions. I don't think I will use the KillUndoOnSaved script, but I do think I will make a shortcut that calls the EmptyUndoBuffer() and saves the document. I think will call it HardSave (as apposed to a soft save which leaves the undo buffer in place).

   Posted 2 years ago #
5. 

   NickDMax
   Member

   Oh one more thing -- I really love PN (even if it contributed to a rewrite of a couple of days of code) and PyPN is a huge part of why I love PN. When a program ticks you off, as a programmer, it is awesome that you can do something about it! Especially if it is just a couple of lines of Python to keep a problem from happening again!

   Posted 2 years ago #

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