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iosobjective-cxcodewatchkit

Empty documents directory after creating file with NSFileHandle

I'm writing an application for the Apple watch. I'm using the following method (from this SE answer) to write to a log file:

- (void) writeLogWith: (NSString *) content {

    //Get the file path
    NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
    NSString *fileName = [documentsDirectory stringByAppendingPathComponent:@"whathappened.md"];

    //create file if it doesn't exist
    if(![[NSFileManager defaultManager] fileExistsAtPath:fileName])
        [[NSFileManager defaultManager] createFileAtPath:fileName contents:nil attributes:nil];

    //append text to file (you'll probably want to add a newline every write)
    NSFileHandle *file = [NSFileHandle fileHandleForUpdatingAtPath:fileName];
    [file seekToEndOfFile];
    [file writeData:[content dataUsingEncoding:NSUTF8StringEncoding]];
    [file closeFile];

    return;
}

I'm running it by plugging in my phone and running it directly on my watch. The function is definitely executing (I've stepped thought with the debugger) and it also knows that the file exists and doesn't repeatedly try and create it.

Xcode tells me that the file information is: 

Printing description of documentsDirectory:
/var/mobile/Containers/Data/PluginKitPlugin/8503AD6C-6EC9-4522-A867-27109B01B615/Documents
Printing description of documentsDirectory:
(NSString *) documentsDirectory = 0x16d66890
Printing description of fileName:
(NSString *) fileName = 0x16d66950
Printing description of fileName:
/var/mobile/Containers/Data/PluginKitPlugin/8503AD6C-6EC9-4522-A867-27109B01B615/Documents/whathappened.md

I'd like to know if it's writing things correctly, but when I look at the container (following these SE answers), the documents directory is empty. enter image description here

My question is: where did my file go? And how can I find it?

Solution

  • From other research, the answer appears to be:

    If you are storing a file on the Apple Watch, it is stored in it's own container, which isn't visible via xcode.

    It indeed, appears to be related to this bug report: https://openradar.appspot.com/radar?id=5021353337946112, found via this SE: How to export shared container of an iOS App with Xcode6.2?