[SOLVED] Validating each property before returning object

Validating each property before returning object

While using Mantle, is there a possibility to before returning the object we are creating (on this case via JSON) to verify that X and Y properties are not nil?

Imagine this class:

@interface Person : MTLModel <MTLJSONSerializing>

@property(nonatomic,strong,readonly)NSString *name;
@property(nonatomic,strong,readonly)NSString *age;

@end

I want a way to verify that if the JSON I received doesn't have the name (for some reason there was an issue on server's DB) I will return a nil Person, as it doesn't make sense to create that object without that property set.

Solution

You can use the MTLJSONSerializing protocol method classForParsingJSONDictionary: to return nil rather than an invalid object:

// In your MTLModelSubclass.m
//
+ (Class)classForParsingJSONDictionary:(NSDictionary *)JSONDictionary {
    if (JSONDictionary[@"name"] == nil || JSONDictionary[@"age"] == nil) {
        return nil;
    }
    return self.class;
}