Hi, Many thanks for your reply, much appreciated - it all helps. I've spent the last couple of hours digging deeper into this, and I think what I'm going to try to do next is override at a slightly lower level, by overriding -writeSafelyToURL:ofType:forSaveOperation:error:. I found the part of the documentation that shows a diagram of the sequence of save events, and it turns out that this is the method that sets up the temporary folders and URLs that get passed into -writeToURL:... If I override and do my writing inside the package there, I think it should work. The docs say that you should always call super inside that method, but I found an Apple sample project, QTKitCreateMovie, that doesn't, and which shows this method being overridden to do something similar to what I want to do. Certainly that is the method that creates the behaviour that I want to change, so I am hopeful...
Thanks again and all the best, Keith ----- Original Message ---- From: Michael Nickerson <[EMAIL PROTECTED]> To: Keith Blount <[EMAIL PROTECTED]> Cc: Cocoa-Dev List <cocoa-dev@lists.apple.com> Sent: Thursday, May 8, 2008 5:45:10 PM Subject: Re: Saving only required files in a file wrapper? On May 8, 2008, at 7:30 AM, Keith Blount wrote: > Apologies for so soon a follow up, but I've just been experimenting > with -writeToURL:ofType:forSaveOperation:originalContentsURL:error: > and the results are disastrous. It turns out that *every single > time* it is invoked, absoluteURL is a temporary location and *not* > the original URL. So to use this method successfully I would need to > copy the whole file package across to that location every time, > which is exactly what I _don't_ want to do. This seems a little > insane to me. There must be a mechanism in place that just lets you > save into a package folder without having to write the whole thing > out every time... > > Thanks again and all the best, > Keith > I went through some of this recently - I'm using a helper tool to actually save the files, and I had to figure some of this out to get that working right. absoluteURL is going to always be a temp location because that's how the document system works - it writes to the temp location, then overwrites the original location if that's successful. Keeps file corruption to a minimum. absoluteOriginalContentsURL should probably be the original URL. The only time it's not likely to be the original path (what's returned by [self fileURL]) is if the user has moved / renamed the original file in between when it was opened and when it's being saved. (I'm fairly certain this is why you're told not to use -fileURL when writing - because that's not updated if the user moves / renames the file while it's being edited.) If you don't want to rely on that, there's nothing stopping you from creating a new ivar to save the URL passed in when you read the file. Though that can break if the user moves / renames the file while it's being edited. I know, not likely, but you can't be 100% certain on that. If you'd like to do this, but want to be certain, you could get the original path when you read and convert it to a file alias, then resolve the alias when you're writing - then you're guaranteed to have the correct path (this is what I actually decided to do). The only way that would break is if the user moves the file to a different hard drive, and I believe the normal NSDocument methods wouldn't work correctly in that case anyway (I believe the user gets shown a dialog saying the original file couldn't be found). Once you have the original path (whichever way you choose to get it), you can do what you were before to save the files in the wrapper. Or, if you want to, you can save it to the temp location, and then overwrite the individual files yourself using NSFileManager. Though if you do that, *make sure to delete the temp file* before returning (if you use the same path as absoluteURL for the temp file, anyway). If you don't, the document system will copy it over anyway and you'll wind up with your original problem. I had an interesting time figuring that last part out. In my case, the original files aren't actually writable by anyone but root, and it would "fail" when it tried to copy the temp files over the original files (even though my helper tool had actually already done that). Made for an interesting case where the file was actually saved but the app didn't think so. Hope that helps out some. -------------------------------------- Darkshadow (aka Michael Nickerson) http://www.nightproductions.net ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
