iOS7: Saving settings to file doesn't work on device [duplicate] - ios

Question

This question already has answers here:
File write with [NSBundle mainBundle] fails
(5 answers)
Closed 8 years ago.
I'm reading and writing variables to a text file in my app.
It works perfectly fine when testing it in the simulator, but somehow when testing it on the iPhone it can only read the file but not write/save anything
Here's my method for saving my variables ("\n" is used for line breaking):
NSString path = [[NSBundle mainBundle] pathForResource:#"settings" ofType:#"txt"];
- (void)saveSettings {
[[NSString stringWithFormat:#"%d\n%d", firstInt, secInt] writeToFile:path atomically:YES encoding:NSUTF8StringEncoding error:nil];
}
As I said: works in the simulator but doesn't work on any iDevice.
Does anyone got a idea why it's not working? Changing "atomically" to "NO" does nothing

Answer 1

You can't write to the bundle. Among other reasons because the bundle is part of the signature in the app and that can't be changed. You can write to other directories, en particular the Documents directory
NSArray *paths = NSSearchPathForDirectoriesInDomains
(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *write_file = [NSString stringWithFormat:#"%#/settings.txt",
documentsDirectory];
You will be able to write to write_file.

Answer 2

Short answer: You can't write into the main bundle.
Long answer: You should really use the preferences for this:
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setObject:[NSString stringWithFormat:#"%d\n%d", firstInt, secInt]
forKey:#"yourPref"];
BOOL saved = [prefs synchronize];
or even better, like that:
NSInteger firstInt = 0;
NSInteger secInt = 0;
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setInteger:firstInt forKey:#"firstInt"];
[prefs setInteger:secInt forKey:#"secInt"];
BOOL saved = [prefs synchronize];