In my attempt to redesign an existing application using REST architectural style, I came across a problem which I would like to term as "Mediatype Explosion". However, I am not sure if this is really a problem or an inherent benefit of REST. To explain what I mean, take the following example
One tiny part of our application looks like:
collection-of-collections->collections-of-items->items
i.e the top level is a collection of collections and each of these collection is again a collection of items.
Also, each item has 8 attributes which can be read and written individually. Trying to expose the above hierarchy as RESTful resources leaves me with the following media types:
application/vnd.mycompany.collection-of-collections+xml
application/vnd.mycompany.collection-of-items+xml
application/vnd.mycompany.item+xml
Further more, since each item has 8 attributes which can be read and written to individually, it will result in another 8 media types. e.g. one such media type for "value" attribute of an item would be:
application/vnd.mycompany.item_value+xml
As I mentioned earlier, this is just a tiny part of our application and I expect several different collections and items that needs to be exposed in this way.
My questions are:
- Am I doing something wrong by having these huge number of media types?
- What is the alternative design method to avoid this explosion of media types?
I am also aware that the design above is highly granular, especially exposing individual attributes of the item and having separate media types for each them. However, making it coarse means I will end up transferring unnecessary data over the wire when in reality the client only needs to read or write a single attribute of an item. How would you approach such a design issue?