Support for various JSON libraries

[magnolia-k]

I wrote a prototype of support for Spray-Json and Argonaut

Spray-JSON

magnolia-k@46d8a5c

Argonaut

magnolia-k@caad122

Things to decide to support various JSON libraries

• JSONP support
• Generate response directly from case class
• Which JSON library to support

[takezoe]

@magnolia-k Great! I will check your code as soon as possible.

[takezoe]

Generate response directly from case class

I think it's impossible to make with the current Scalatra API because it allows any types as the result of the action. Dramatic changes in core API is necessary.

My idea is defining a type class like Renderable[T] and each action take an instance corresponding to a result type of itself. Of course, it affects not only JSON actions, but all actions.

Which JSON library to support

spray-json and argonaut is good start of the multiple JSON library support in Scalatra!

[magnolia-k]

thank you for your comment
As you pointed out, I think that it is difficult to support other JSON libraries in the same way, as the current JSON support strongly depends on Json4s specific functions.

There seems to be a need to think towards the function of Scalatra 3.0 (?).

First of all, prepare for Scalatra 2.7 with case class support removed.

[takezoe]

There seems to be a need to think towards the function of Scalatra 3.0 (?).

Make sense.

First of all, prepare for Scalatra 2.7 with case class support removed.

What does it mean?

[magnolia-k]

What does it mean?

If we put Spray-Json and Argonaut's support in 2.7, we mean we have to decide whether or not to add without support for case class

It does not mean to remove case class support from json4s.
(I was sorry that the explanation was insufficient)

[takezoe]

I totally understood.

While that's nice as a first step of multiple JSON library support, I would like to consider introducing the type class to render response. But I'm not sure whther it's possible to introduce it in Scalatra 2.7 at the moment.

We will able to consider case class support in JSON support after that.