How to write a data in plist?

I have followed this answer to write data to the plist

How to write data to the plist?

But so far my plist didn't change at all.

Here is my code :-

- (IBAction)save:(id)sender
{
    NSString *path = [[NSBundle mainBundle] pathForResource:@"drinks" ofType:@"plist"];
    NSString *drinkName = self.name.text;
    NSString *drinkIngredients = self.ingredients.text;
    NSString *drinkDirection = self.directions.text;
    NSArray *values = [[NSArray alloc] initWithObjects:drinkDirection, drinkIngredients, drinkName, nil];
    NSArray *keys = [[NSArray alloc] initWithObjects:DIRECTIONS_KEY, INGREDIENTS_KEY, NAME_KEY, nil];
    NSDictionary *dict = [[NSDictionary alloc] initWithObjects:values forKeys:keys];
    [self.drinkArray addObject:dict];
    NSLog(@"%@", self.drinkArray);
    [self.drinkArray writeToFile:path atomically:YES];
}

Do I need to perform something extra?

I am new to iPhone SDK so any help would be appreciated.

You are trying to write the file to your application bundle, which is not possible. Save the file to the Documents folder instead.

NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
path = [path stringByAppendingPathComponent:@"drinks.plist"];

The pathForResource method can only be used for reading the resources that you added to your project in Xcode.

Here's what you typically do when you want to modify a plist in your app:
1. Copy the drinks.plist from your application bundle to the app's Documents folder on first launch (using NSFileManager).
2. Only use the file in the Documents folder when reading/writing.

UPDATE

This is how you would initialize the drinkArray property:

NSString *destPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
destPath = [destPath stringByAppendingPathComponent:@"drinks.plist"];

// If the file doesn't exist in the Documents Folder, copy it.
NSFileManager *fileManager = [NSFileManager defaultManager];

if (![fileManager fileExistsAtPath:destPath]) {
    NSString *sourcePath = [[NSBundle mainBundle] pathForResource:@"drinks" ofType:@"plist"];
    [fileManager copyItemAtPath:sourcePath toPath:destPath error:nil];
}

// Load the Property List.
drinkArray = [[NSArray alloc] initWithContentsOfFile:destPath];