Question

Plist is copyed to documents directory if it doesn’t exist.

If it already exists, I want to use the “Name” key from NSDictionary in bundleArray to find the matching NSDictionary in documentsArray.

When the match is found, I want to check for changes in the strings and replace them if there is a change.

If a match is not found it means this dictionary must be added to documents plist.

This is my code:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
[self managePlist];
return YES;
}

- (void)managePlist {

NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:@"Objects.plist"];
NSString *bundle = [[NSBundle mainBundle] pathForResource:@"Objects" ofType:@"plist"];
NSFileManager *fileManager = [NSFileManager defaultManager];

if (![fileManager fileExistsAtPath: path]) {
    [fileManager copyItemAtPath:bundle toPath:path error:&error];

} else {

    NSArray *bundleArray = [[NSArray alloc] initWithContentsOfFile:bundle];
    NSMutableArray *documentArray = [[NSMutableArray alloc] initWithContentsOfFile:path];

    BOOL updateDictionary = NO;
    for(int i=0;i<bundleArray.count;i++) {

        NSDictionary *bundleDict=[bundleArray objectAtIndex:i];

        BOOL matchInDocuments = NO;
        for(int ii=0;ii<documentArray.count;ii++)
        {
            NSMutableDictionary *documentDict = [documentArray objectAtIndex:ii]; 
            NSString *bundleObjectName = [bundleDict valueForKey:@"Name"];
            NSString *documentsObjectName = [documentDict valueForKey:@"Name"];
            NSRange range = [documentsObjectName rangeOfString:bundleObjectName options:NSCaseInsensitiveSearch];
            if (range.location != NSNotFound) {
                matchInDocuments = YES;
            }
            if (matchInDocuments) {

                if ([bundleDict objectForKey:@"District"] != [documentDict objectForKey:@"District"]) {
                    [documentDict setObject:[bundleDict objectForKey:@"District"] forKey:@"District"];
                    updateDictionary=YES;
                }
            }

            else {
                [documentArray addObject:bundleDict];
                updateDictionary=YES;
            }
        }
    }
    if(updateDictionary){
        [documentArray writeToFile:path atomically:YES];
    }

}

}

If I run my app now I get this message: '-[__NSCFDictionary setObject:forKey:]: mutating method sent to immutable object'

How can I fix this?

When this is fixed, do you think my code will work?

If not, I would be happy for some suggestions on how to do this. I have struggled for a while and really need to publish the update with the corrections! Thanks a lot for your help.

Answer 1

Presumably the documentDict is actually immutable. Even though you assign it to an NSMutableDictionary, this doesn’t accurately describe the underlying data.

NSMutableDictionary *documentDict = [documentArray objectAtIndex:ii];

should be:

NSMutableDictionary *documentDict = [NSMutableDictionary dictionaryWithDictionary:[documentArray objectAtIndex:ii]];

and wherever you edit the documentDict, add:

 [documentArray replaceObjectAtIndex:ii withObject:documentDict];