How to set default value in iOS Mantle model subclass

Question

@interface Entity ()
  @property (assign) int searchTotalPagesAll;
  @property (assign) int searchTotalPagesIdeas;
@end


@implementation Entity
  + (NSDictionary *)JSONKeyPathsByPropertyKey {
return @{
         @"Id": @"entity.id_entity",
         @"name": @"entity.name",
         @"coverage" : @"entity.coverage",
         @"id_city": @"entity.Id_City",
         @"cityName":@"entity.city",
         @"countryName":@"entity.country",
         @"stateName":@"entity.district",
         @"countryCode": @"entity.countrycode",
         @"keyword1": @"entity.key1",
      ... etc

Since mantle examples doesn't have a init method, where should I initialize those properties (searchTotalPagesAll, searchTotalPagesIdeas) for default values ? This model has internal methods that need this and several other properties.

score 13 · Accepted Answer · answered Apr 23 '14 at 13:00

13

Whether you create a Mantle model from JSON or otherwise, the model is initialised with [-initWithDictionary:error:]. In your model class, you can add your defaults to the values used to initialise the model:

- (instancetype)initWithDictionary:(NSDictionary *)dictionaryValue error:(NSError *__autoreleasing *)error {
    NSDictionary *defaults = @{
        @"searchTotalPagesAll" : @(10),
        @"searchTotalPagesIdeas" : @(5)
    };
    dictionaryValue = [defaults mtl_dictionaryByAddingEntriesFromDictionary:dictionaryValue];
    return [super initWithDictionary:dictionaryValue error:error];
}

answered Apr 23 '14 at 13:00

David Snabel-Caunt

57,804
13
114
132

If I initialize in this way: [[MyMantleModelClass alloc] init] it won't trigger [-initWithDictionary:error:]. How can I force the former initializer to call the latter without they calling each other? thx. – Golden Thumb Feb 07 '15 at 14:23
1

If you aren't using `initWithDictionary` then you can just set the property values in `init`. – David Snabel-Caunt Feb 07 '15 at 18:02

score 9 · Answer 2 · answered Oct 15 '14 at 11:10

9

You can set the default value in init method.

- (instancetype)init
{
    self = [super init];
    if (self) {
        self.searchTotalPagesAll = 1;
        self.searchTotalPagesIdeas = 2;
    }
    return self;
}

answered Oct 15 '14 at 11:10

Hilen

761
7
8

2

Makes sense, and is simpler than the approach in the accepted answer. – ZeMoon May 07 '15 at 15:25

How to set default value in iOS Mantle model subclass

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