Question

I have 30 Rooms and each Room should have 5 same RoomAttributes.

I have a many to many relationship between Room and RoomAttributes.

My Solutions was, to create 30 * 5 = 150 RoomAttributes and make NSSet’s of RoomAttributes for every Room. This is allot of work.

How i creat a Room:

Raum *raum = [NSEntityDescription insertNewObjectForEntityForName:@"Raum" inManagedObjectContext:context];

raum.raumName = @"Main";
raum.etage = @"2. Stock, Raum 1.203";
raum.beschreibung = @"Gut beleuchtet";
raum.raumpreis = [NSNumber numberWithDouble:210];
raum.raumname = @"Besprechungsraum";

How i create RoomAttributes:

Raumattribute *attribute =[NSEntityDescription insertNewObjectForEntityForName:@"Raumattribute" inManagedObjectContext:context];
    attribute.attributname = @"Beamer";
    attribute.schalter = [NSNumber numberWithBool:NO];

    Raumattribute *attribute2 =[NSEntityDescription insertNewObjectForEntityForName:@"Raumattribute" inManagedObjectContext:context];
    attribute2.attributname = @"Behindertengerecht";
    attribute2.schalter = [NSNumber numberWithBool:NO];

How i create the NSSet:

NSSet *attributeFurRaum = [NSSet setWithObjects:attribute1, attribute2,nil];  
raum.raumattribute = attributeFurRaum;

How can i make this easier?

Answer 1

**EDITED

ahh I see – sorry I misunderstood the original question – the edit makes it easier.

For that I would create three helper methods

-(RaumAttribute*)roomAttributeWithName:(NSString *)name andSchalter:(BOOL)schalter
{
    Raumattribute *att =[NSEntityDescription insertNewObjectForEntityForName:@"Raumattribute" inManagedObjectContext:context];
    att.attributname = name;
    att.schalter = schalter;
    return att;
}

-(NSSet *)roomAttributes
{
    NSArray *atts = [@"Beamer,Behindertengerecht" componentsSeparatedByString:@","];
    NSMutableSet *roomAttributes = [NSMutableSet set];
    for(NSString *name in atts)
    {
        [roomAttributes addObject:[self roomAttributeWithName:name andSchalter:NO]];
    }
    return roomAttributes;
}

-(Raum *)raumFromDictionary:(NSDictionary *)details
{
    Raum *raum = [NSEntityDescription insertNewObjectForEntityForName:@"Raum" inManagedObjectContext:context];
    raum.raumName = [details valueForKey:@"raumName"];
    raum.etage = [details valueForKey:@"etage"];
    raum.beschreibung = [details valueForKey:@"beschreibung"];
    raum.raumpreis = [details objectForKey:@"raumpreis"];
    raum.raumname = [details objectForKey:@"raumname"];
    return raum;
}

then you could store your pre-determined object data in a plist or JSON – parse it into a dictionary then go something like:

NSArray *raumDictionaries = //code to get array of dictionaries from a plist or whatever  source
NSSet *raumAttributeSet = [self roomAttributes];
for(NSDictionary *raumDict in raumDictionaries)
{
    Raum *raum = [self raumFromDictionary:raumDict];
    raum.raumattribute = raumAttributeSet;
    //save context
}