Support for Mapping Entity Based on Internal Data

[blakewatters]

Hi,

I need to have a mapping from JSON to my entities that is a bit more
complex than the default mapping that maps from the JSON outer key to
an entity.

There are two different cases of the problem

1- The API returns a payload with a JSON type of "Result" for many
different queries. The content of the "Result" structure is totally
unrelated to any other, only to the initial query. How could I handle
such a mapping?

2- Sometimes the payload I get under the same JSON type differs
depending on one inner field, usually called xxxKind. Here is a
contrived example:

{"Results":[
   { "Person": { "Name": "John", "Sex": "M"}},
   { "Person": { "Name": "Jane", "Sex": "F"}}
]}

And here I would like to instanciate John as a "Man" entity, and
"Jane" as a "Woman" entity.
Most probably, "Man" and "Woman" would be subentities of an abstract
"Person" entity.

How could I handle such a mapping?

I think it would be enough if I had a delegate method that would look
into the parsed directory from the JSON parser in order to decide and
return the name of the entity to instanciate,

Or something along those lines.

Thanks for any suggestion...

[SaschaKonietzke]

Currently investigating if we can use RestKit and already saw this on the mailing list. We have the same requirement and it would be great to see this included.

+1

[blakewatters]

Moving to 0.9.4

[houseoflegend]

Hey Blake! Saw the forum post on this one and looked it up here. +1 for as well.

An example of our use case might be more like this:
{"Person" : {"Name: "John", ...}}
maps to Person abstract entity in Core Data

{"Person": { "Name": "John", "tools": {"Hammer", "Screwdriver", "Drill"}}}
maps to Carpenter class, which has Person abstract entity as its Parent Entity.

{"Person": { "Name": "John", "specialty_dish": "Lasagna"}}
maps to Chef class, which also has Person abstract entity as its Parent Entity.

[blakewatters]

Alright, I am reopening this on 0.9.3 as the final task for the release. It's in the core of the object mapper and I want to focus primarily on Core Data in 0.9.4, so let's knock out the design vetted in #244

[houseoflegend]

Terrific, thanks for the update Blake!