How to handle unexpected data types with Mantle

In my MTLModel subclass I have this:

@property (assign, nonatomic) NSInteger catId; 

And of course this in the implementation:

+ (NSDictionary *)JSONKeyPathsByPropertyKey {     return @{               @"catId" : @"cat_id"               };  } 

But what if my server friends decide to change cat_id to a string in the JSON response? How can I handle this case, and convert it to an int so that I don't get Mantle errors?

3 Answers

Answers 1

if([obj isKindOfClass:NSClassFromString(@"__NSCFNumber")]) { //if it is int or number } else {  } 

May be above method will help you

Answers 2

use id as datatype

@property (assign, nonatomic) id catId; 

Answers 3

We also used Mantle for quite some time, but at the end migrated to handwritten parser/serializers, as the task itself seem to be trivial.

Though, we also have this kind of problems: what if server return something we do not expect (e.g. NSDictionary instead of NSString).

To prevent our app from crashing we use this simple tool: Fuzzer.

Basically the tool provides a method that takes a sample and a block. The block evaluates several times, each time bringing slightly mutated version of the sample. You can check behaviour of the models/parsers/serializers using the mutants, to ensure that your code handles unexpected data gracefully.

Here is example taken from project's README:

- (void)test {   NSDictionary *sample = @{     @“name” : @“John Doe”,     @“age” : @42   };    UserDeserializer *deserializer = [UserDeserializer new];    FZRRunner *runner = [FZRRunner runnerWithBuiltinMutationsForSample:sample];    NSArray *reports = [runner enumerateMutantsUsingBlock:^(NSDictionary *mutant) {     [deserializer deserializeUser:mutant];   }];    XCTAssertEqual(reports.count, 0); } 

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