iOS MVC - Passing data back and forth to view controllers and model

Question

I\'m new to iOS programming and having written a simple reminders style app, I\'m now rewriting it to implement the MVC model correctly as previously all my code was inside View

Answer 1

You can store the collection of Event in NSUserDefaults. Since its a custom class, you need to implement NSCoding protocol for serialization to NSUserDefaults.

//Event.h

    @interface Event : NSObject<NSCoding>

    @property (nonatomic, copy)   NSString *name;
    @property (nonatomic, strong) NSDate *time;
    @property (nonatomic) NSInteger repeat;

    - (void)save;
    + (NSArray *)allEvents;

//Event.m
#define kSavedEvents @"SavedEvents"

#pragma mark - Encoding
- (void)encodeWithCoder:(NSCoder *)encoder
{
    [encoder encodeObject:self.name  forKey:@"EventName"];
    [encoder encodeObject:self.time forKey:@"EventTime"];
    [encoder encodeObject:@(self.repeat) forKey:@"EventRepeat"];

}

#pragma mark - Decoding
- (id)initWithCoder:(NSCoder *)decoder
{
    self = [super init];
    if (self)
    {
        _name   = [decoder decodeObjectForKey:@"EventName"];
        _time   = [decoder decodeObjectForKey:@"EventTime"];
        _repeat = [[decoder decodeObjectForKey:@"EventRepeat"]integerValue];

    }
    return self;
}

You need to archive the data while storing to NSUserDefaults and unarchive when fetching

 (void)save
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    NSData *savedData = [defaults objectForKey:kSavedEvents];


    NSMutableArray *savedEvents = [@[] mutableCopy];

    //Some events are already there in there
    if (savedData) {
        savedEvents = [[NSKeyedUnarchiver unarchiveObjectWithData:savedData]mutableCopy];
    }

    [savedEvents addObject:self];

    //Archiving the savedEvents to data
    NSData *newEventData = [NSKeyedArchiver archivedDataWithRootObject:savedEvents];

    [defaults setObject:newEventData forKey:kSavedEvents];
    [defaults synchronize];
}

+ (NSArray *)allEvents
{
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    NSData *data = [defaults objectForKey:kSavedEvents];
    if (data)
    {
        return [NSKeyedUnarchiver unarchiveObjectWithData:data];
    }
    return nil;
}

Hope this will get you started.