How to handle a corrupted plist programatically

Targets macOS
1

I access my app’s plist on launch to read/write a preference setting. I’ve had several occasions where a user was unable to launch the app due to corrupted XML in the plist. It tell them where the file is and to remove it, which fixes the problem. But I wonder if I can do this programatically. That is, if I put the plist read in a try block and get an exception, can I have my app delete the plist file and replace it with the info.plist file( in the app’s bundle), renaming it com.mycompany.myapp.plist? Or will that cause problems?

2

Are you reading it manually ?

3

Yes, like this, using a shell to convert the plist to XML

sh.execute "plutil -convert xml1 " + f.ShellPath //converts binary plist to xml so we can read it.
ti = f.OpenAsTextFile
s = ti.ReadAll

then

xdoc = new XmlDocument(s)

But I’m not asking why the plist is sometimes corrupted, that can happen with any app (and it’s very rare with mine, but with thousands of users I do get the occasional report). I’m wondering if I can put the

new XMLDocument(s)

in a try-catch block and, if an exception is thrown, replace the problematic plist with a new copy of the info.plist in the app bundle.

4

Yes you can put the XML doc reading in a try catch
But you shouldn’t be doing this this way anyways
Use CFPreferences directly and it takes care of all that for you

5

Thanks. Do you mean use CFPreferences via Declares (i.e. using MacOSLib)?

6

Yes
It’s not so bad and because you use the official API it will already handle binary & text plists

7

Thank you for the help, I’ll give it a shot.

8

You want NSBundle for accessing the info.plist file within your application bundle.

9

Oh and don’t write to it, you’ll break the application code signature.

10

I wouldn’t write to info.plist. The most I’d do would be to make a copy to replace the app .plist.