Writing to mainBundle plist

Question

i have a question i created a plist of movies. Root is of type Dictionary and Pixar type Array with 3 string movie titles I am able to read from the list with the following code no problem

NSString *path = [[NSBundle mainBundle] pathForResource:@"Movies" ofType:@"plist"];

NSMutableDictionary *movies =[[NSMutableDictionary alloc] initWithContentsOfFile:path];

from here i can print the list no problem. I want to add another movie to this list now. so i transfered the list to a array and then saved the array back to the file but its not working. any idea of where i went wrong?

NSMutableArray *array= [movies valueForKey:@"Pixar"];
NSString *incredible=@"Incredibles";
[array addObject:incredible];

[movies setObject:array forKey:@"Pixar"];

[movies writeToFile:path atomically:YES];

Answer 1

You cannot, on the device, write to the bundle. The simulator doesn't enforce these constraints, but the device will.

One approach is to:

1. See if the file exists in the Documents folder.

2. If it does, read it from the Documents folder. If not, read it from the bundle.

3. When done adding/removing records, write the file to the Documents folder.

Thus:

NSString *bundlePath    = [[NSBundle mainBundle] pathForResource:@"Movies" ofType:@"plist"];
NSString *docsFolder    = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)[0];
NSString *documentsPath = [docsFolder stringByAppendingPathComponent:@"Movies.plist"];

NSMutableDictionary *movies = nil;

if ([[NSFileManager defaultManager] fileExistsAtPath:documentsPath])
    movies = [NSMutableDictionary dictionaryWithContentsOfFile:documentsPath];

if (!movies)
    movies = [NSMutableDictionary dictionaryWithContentsOfFile:bundlePath];

// do whatever edits you want

[movies writeToFile:documentsPath atomically:YES];