Use sandbox to open one file and can access to another with the same name

Question

I would to open myfile.plist with the NSOpenpPanel but I would to acess to myfile.png also if the user has just selected the plist one. I've already tried to access to the png doing

NSString* url = [[NSString stringWithFormat:@"file://localhost%@%@%@", pathWithoutFilename, @"/", imageFileName ]stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

but doing:

NSData* imageData = [[NSData alloc] initWithContentsOfURL:nsurl];
NSImage *sourceImage = [[NSImage alloc] initWithData:imageData];

NSImage is nil.

How i can?

Answer 1

Here is the right Trick to save and Retreive Bookmark with NSURLBookmarkCreationWithSecurityScope for Sandbox Cocoa App: Finally

-(void)saveTheNSData:(NSData *)data withFileName:(NSString *)fileName
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *filePath = [documentsDirectory stringByAppendingPathComponent:fileName];

    [data writeToFile:filePath atomically:NO];
}

-(NSURL*) getNSURLFromBookmarkIfExists:(NSString*) filename forType:(NSString*) type
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    NSString *filePath = [documentsDirectory stringByAppendingPathComponent:filename];

    NSData* data = [[NSData alloc] initWithContentsOfFile: filePath];
    if(data != nil)
    {
        NSURL* outUrl = [NSURL URLByResolvingBookmarkData:[[NSUserDefaults standardUserDefaults] objectForKey:type] options:NSURLBookmarkResolutionWithSecurityScope relativeToURL:nil bookmarkDataIsStale:nil error:nil];
        [outUrl startAccessingSecurityScopedResource];
        return outUrl;
    }
    else
        return nil;
}

Also plese look at this example for the correct way to set up the bookmark using [NSUserDefaults standardUserDefaults] that does the trick:

-(void) savePlistWithPlistUrl:(NSURL*) plistUrl andImageUrl:(NSURL*) imageUrl
{
    NSData *bookmarkPlist = [self bookmarkFromURL:plistUrl];

    NSArray* pathSplitted = [pathFilePlist pathComponents];
    NSString* filenamePlist = [pathSplitted objectAtIndex:[pathSplitted count]-1];

    NSData *bookmarkImage = [self bookmarkFromURL:imageUrl];

    NSArray* pathImageSplitted = [imageUrl pathComponents];
    NSString* filenameImage = [pathImageSplitted objectAtIndex:[pathImageSplitted count]-1];

    NSUserDefaults* prefs = [NSUserDefaults standardUserDefaults];
    [prefs setObject:bookmarkPlist forKey:@"ExportPlist"];
    [prefs setObject:bookmarkImage forKey:@"ExportImage"];
    [prefs synchronize];
    // save the data bookmark
    [self saveTheNSData: bookmarkPlist withFileName:filenamePlist];
    [self saveTheNSData: bookmarkImage withFileName:filenameImage];
}