NSFileManager - Copying Files at Startup

Question

Hi,

I need to copy a few sample files from my app's resource folder and place them in my app's document folder. I came up with the attached code, it compiles fine but it doesn't work. All the directories I refer to do exist. I'm not quite sure what I am doing wrong, could someone point me in the right direction please?

NSFileManager*manager = [NSFileManager defaultManager];

NSString*dirToCopyTo = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];

NSString*path = [[NSBundle mainBundle] resourcePath];

NSString*dirToCopyFrom = [path stringByAppendingPathComponent:@"Samples"];


NSError*error;

NSArray*files = [manager contentsOfDirectoryAtPath:dirToCopyFrom error:nil];

for (NSString *file in files)
{
        [manager copyItemAtPath:[dirToCopyFrom stringByAppendingPathComponent:file] toPath:dirToCopyTo error:&error];

        if (error)
        {
            NSLog(@"%@",[error localizedDescription]);
    }
}

EDIT: I just edited the code the way it should be. Now however there's another problem:

2010-05-15 13:31:31.787 WriteIt Mobile[4587:207] DAMutableDictionary.h 2010-05-15 13:31:31.795 WriteIt Mobile[4587:207] FileManager Error:Operation could not be completed. File exists

EDIT : I have fixed the issue by telling NSFileManager the names of the copied files's destinations.

        [manager copyItemAtPath:[dirToCopyFrom stringByAppendingPathComponent:file] toPath:[dirToCopyTo stringByAppendingPathComponent:file] error:&error];

Answer 1

I think the problem is in this line:

NSArray*files = [manager contentsOfDirectoryAtPath:dirToCopyTo error:nil];

You are listing files in a destination directory instead of the source. Change it to something like:

NSArray*files = [manager contentsOfDirectoryAtPath:dirToCopyFrom error:nil];

And you should be fine.

Answer 2

I think the problem is that yo are reading the files to copy from dirToCopyTo and I think you meant dirToCopyFrom

Also to get the documents directory you should be using NSDocumentDirectory with - (NSArray *)URLsForDirectory:(NSSearchPathDirectory)directory inDomains:(NSSearchPathDomainMask)domainMask

Answer 3

    [manager copyItemAtPath:[dirToCopyFrom stringByAppendingPathComponent:file] toPath:dirToCopyTo error:&error];

The destination path is the path you want the copy to have, including its filename. You cannot pass the path to a directory expecting NSFileManager to fill in the name of the source file; it will not do this.

The documentation says that the destination path must not describe anything that exists:

… dstPath must not exist prior to the operation.

In your case, it's the path to the destination directory, so it does exist, which is why the copy fails.

You need to make it a path to the destination file by appending the desired filename to it. Then it will not exist (if not previously copied), so the copy will succeed.