how to save new NSMutableDictionary to a property list

Question

i've got this method here which runs through every time I press save:

-(void)setName:(NSString *)foodName andCarbs:(NSNumber *)carbAmount{
    [self.userFoodDictionary setObject:(NSString *)foodName forKey:(NSString *)foodName];
    NSString *value = [[NSString alloc] initWithFormat:@"%@ Value", foodName];
    [self.userFoodDictionary setObject:(NSNumber *)carbAmount forKey:(NSString *)value];
    [self.userFoodDictionary writeToFile:self.appDataPath atomically:YES];
}

From my understanding, the second last line should save the userFoodDictionary properties to the specified property list path. But that doesn't seem to happen once. I rebuild the application. Maybe my way of creating a new dictionary object is incorrect. Could someone please explain why this isn't working?

Answer 1

Write to Plist

- (NSString *)foodDataPlistFilePath
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *filePath = [documentsDirectory stringByAppendingPathComponent:@"UserFoodData.plist"];

    return filePath;
}

...

-(void)setName:(NSString *)foodName andCarbs:(NSNumber *)carbAmount{
    [self.userFoodDictionary setObject:(NSString *)foodName forKey:(NSString *)foodName];
    NSString *value = [[NSString alloc] initWithFormat:@"%@ Value", foodName];
    [self.userFoodDictionary setObject:(NSNumber *)carbAmount forKey:(NSString *)value];
    NSString *filePath = [self foodDataPlistFilePath];
    [self.userFoodDictionary writeToFile:filePath atomically:YES];
}

Initialize mutable dictionary:

NSString *filePath = [self foodDataPlistFilePath];
BOOL fileExists = [[NSFileManager defaultManager] fileExistsAtPath:filePath];
self.userFoodDictionary = [[NSMutableDictionary alloc] init];
if(fileExists){
    NSDictionary *foodData = [NSDictionary dictionaryWithContentsOfFile:filePath];
    [_userFoodDictionary setDictionary:foodData];
}