Multiple KeyMappers per JSONModel

Question

JSONModel lets you convert a model object into a NSDictionary as following:

NSDictionary *dict = [myJSONModel toDictionary]

It includes all properties of the model (except optional). However, I also need to create multiple dictionaries having only some model fields required for a particular backend operation.

Some fields could be included in multiple dictionaries, so ideally, it would be awesome if I could do something like:

NSDictionary *dictOne = [myJSONModel dictionaryWithKeyMapper:myJSONMapperOne]
NSDictionary *dictTwo = [myJSONModel dictionaryWithKeyMapper:myJSONMapperTwo]

and it only returns the objects that have been mapped in that particular mapper.

Answer 1

I am sure there's nothing like this at present. The keymapper for every class is created only once and then is cached, so you can't changed it programatically. Plus you cannot ignore properties via the keymapper.

JSONModel is built like so that it supposes you always need to do the same transformations when you convert between JSON and your model, this way it can do the performance optimisations it does.

However "toDictionary" is not too complicated, you could try subclassing JSONModel and playing around with implementing a "toDictionaryWithFieldList" that takes in field names list and exports only those fields ... just an idea