Boolean value in the NSDictionary serialized as true/false for x-www-form-urlencoded

Question

RestKit version: 0.27.0

Is there any way how to let RestKit to serialize the boolean value stored in NSDictionary to x-www-form-urlencoded parameters?

I have NSDictionary filled with values, it is propagated to the encoded string:

product=ACCOUNT&rejected=1&type=NUMBER_OF_LOGINS_MONTH

But I need true/false instead of 1 or 0 as the value for rejected parameter.

Is there any way how to use class specification similar to RKAttributeMapping's propertyValueClass to override the default type NSNumber? Also NSNumber is internally implemented as __NSCFBoolean. Is it possible to use this information to serialize the value as true/false?

Answer 1

I have subclassed RKURLEncodedSerialization and copied the implementation from RKAFQueryStringFromParametersWithEncoding:

    static NSString * TSNRKAFQueryStringFromParametersWithEncoding(NSDictionary *parameters, NSStringEncoding stringEncoding) {
        NSMutableArray *mutablePairs = [NSMutableArray array];
        for (TSNRKAFQueryStringPair *pair in TSNRKAFQueryStringPairsFromDictionary(parameters)) {

            if([NSStringFromClass([pair.value class]) isEqualToString:@"__NSCFBoolean"]) {

                pair.value = TSNNSCFBooleanToBooleanStringConvertor(pair.value);
            }

            [mutablePairs addObject:[pair URLEncodedStringValueWithEncoding:stringEncoding]];
        }

        return [mutablePairs componentsJoinedByString:@"&"];
    }

    NSString* TSNNSCFBooleanToBooleanStringConvertor(NSNumber* booleanInNSNumber) {

        return [booleanInNSNumber boolValue] ? @"true" : @"false";
    }

Also remember to copy the other methods/objects and rename them otherwise it will collide when being linked.

The new subclass has to be registered with the RestKit:

[RKMIMETypeSerialization unregisterClass:[RKURLEncodedSerialization class]];
[RKMIMETypeSerialization registerClass:[TSNRKURLEncodedSerialization class] forMIMEType:RKMIMETypeFormURLEncoded];

UPDATE: This solution works for requests with all methods except GET, HEAD and DELETE. These methods still trigger the original serialisation: not true/false, but 1/0.