writeToFile NSDictionary not saving to plist correctly

Question

I have a custom plist that I am using to populate UItableViewCells with, I am able to read them perfectly, however when I try to write to my custom plist file it never changes.

NSString *errorDesc = nil;
NSString * plistPath = [[NSBundle mainBundle] pathForResource:@"AdvanceSearchPrefrences" ofType:@"plist"];
NSMutableDictionary *advPrefs = [NSMutableDictionary dictionaryWithContentsOfFile:plistPath];
[advPrefs setObject:cell.textLabel.text forKey:@"Manuf"];
[advPrefs setObject:selRow forKey:@"ManufNum"];
NSData *plistData = [NSPropertyListSerialization dataFromPropertyList:advPrefs format:NSPropertyListXMLFormat_v1_0 errorDescription:&errorDesc];
[plistData writeToFile:plistPath atomically:YES];


NSString * plistPath2 = [[NSBundle mainBundle] pathForResource:@"AdvanceSearchPrefrences" ofType:@"plist"];
NSMutableDictionary *advPrefs2 = [NSMutableDictionary dictionaryWithContentsOfFile:plistPath2];

The advPrefs shows the new values and advPrefs2 shows the old values.

Answer 1

You can't directly save over your plist, but what you can do is create a copy and save that to NSUserDefaults.

On the initial load you do something like this in your AppDelegate. This will copy your plist into something you can edit and save:

    NSString * plistPath = [[NSBundle mainBundle] pathForResource:@"AdvanceSearchPrefrences" ofType:@"plist"];
    NSMutableDictionary *advPrefs = [NSDictionary dictionaryWithContentsOfFile:plistPath];
    [[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:advPrefs] forKey:@"plist"];
    [[NSUserDefaults standardUserDefaults] synchronize];

In your class that you want to fetch the copied plist, you can call something like this:

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSData *data = [defaults objectForKey:@"plist"];
    NSMutableDictionary *advPrefs = [[NSKeyedUnarchiver unarchiveObjectWithData:data]mutableCopy];

Then make your changes

    [advPrefs setObject:cell.textLabel.text forKey:@"Manuf"];
    [advPrefs setObject:selRow forKey:@"ManufNum"];

And then save them to NSUserDefaults

    [[NSUserDefaults standardUserDefaults] setObject:[NSKeyedArchiver archivedDataWithRootObject:advPrefs] forKey:@"plist"];
    [[NSUserDefaults standardUserDefaults] synchronize];

I had this same problem with my app and this is how I fixed it. Hope this works for you too