New topic: NilObject with FolderItems in use
<http://forums.realsoftware.com/viewtopic.php?t=29730> Page 1 of 1 [ 7 posts ] Previous topic | Next topic Author Message applesource Post subject: NilObject with FolderItems in usePosted: Tue Aug 25, 2009 1:10 pm Joined: Thu Aug 06, 2009 2:25 pm Posts: 90 Location: Oregon I'm having an interesting issue where people are reporting NilObjectExceptions. I've trapped this down and realized it's in an autosave timer. What I need to do is figure out if a file is already being saved/read and if so, NOT to fire the autosave timer's code. What's the proper method of checking if a folderitem is open/in use before attempting to write to it again? Thank you! _________________ AppleSource Software http://www.applesource.biz Top timhare Post subject: Re: NilObject with FolderItems in usePosted: Tue Aug 25, 2009 1:21 pm Joined: Fri Jan 06, 2006 3:21 pm Posts: 6177 Location: Portland, OR USA Probaby easiest to check for nil in your autosave code and bail out if you can't open the file because it's already in use. Top applesource Post subject: Re: NilObject with FolderItems in usePosted: Tue Aug 25, 2009 1:21 pm Joined: Thu Aug 06, 2009 2:25 pm Posts: 90 Location: Oregon In addition, this only occurs under Mac OS X 10.4, under 10.5 there are no issues at all with the auto save timer. Not sure why this is, or what could cause the problem. But ultimately I just need to be able to check to see if a folderitem is already open/in use before I attempt to save the data to it. Any ideas? _________________ AppleSource Software http://www.applesource.biz Top applesource Post subject: Re: NilObject with FolderItems in usePosted: Tue Aug 25, 2009 1:23 pm Joined: Thu Aug 06, 2009 2:25 pm Posts: 90 Location: Oregon Tim, I do check for nil before I do anything with a folderitem. But this issue still occurs on 10.4. What's the best way to check for nil besides just doing an "if not (f is nil) and f.exists then" before opening the file? Should I put an exception to trap a Nil error at the bottom of the routine? Seems weird there isn't just a folderitem.inuse flag, or something similar. _________________ AppleSource Software http://www.applesource.biz Top ZULU Post subject: Re: NilObject with FolderItems in usePosted: Tue Aug 25, 2009 1:37 pm Joined: Mon Jul 31, 2006 1:44 am Posts: 999 I think you need to clarify some ... A folderitem can't be open .... If you mean you get an NilObjectException when trying to write the file, then you not checking the TextOutputStream, if it is that you use ( Can't guess ) So little more info and perhaps your code ... _________________ ------------------------------------ Top timhare Post subject: Re: NilObject with FolderItems in usePosted: Tue Aug 25, 2009 1:40 pm Joined: Fri Jan 06, 2006 3:21 pm Posts: 6177 Location: Portland, OR USA I suspect you're getting the folderitem ok, but it's failing when it tries to return an InputStream (either Text or Binary, depending on how you're accessing the file). Code:dim f as folderitem dim txt as TextInputStream f = GetFolderItem(...) if f<>nil and f.Exists then txt = f.OpenAsTextFile // this returns nil if the file is in use if txt = nil then return // so bail out ... HTH, Tim Top applesource Post subject: Re: NilObject with FolderItems in usePosted: Tue Aug 25, 2009 1:42 pm Joined: Thu Aug 06, 2009 2:25 pm Posts: 90 Location: Oregon I'm using TextInputStream/OutputStream. I will try checking for nil on the streams and see if that reduces or eliminates the errors being received. Thanks for everyone's help. _________________ AppleSource Software http://www.applesource.biz Top Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending Page 1 of 1 [ 7 posts ] -- Over 1500 classes with 29000 functions in one REALbasic plug-in collection. The Monkeybread Software Realbasic Plugin v9.3. http://www.monkeybreadsoftware.de/realbasic/plugins.shtml [email protected]
