Yajl support

[weppos]

This branch adds JSON template support using Yajl.

The template is largely inspired by Builder and Nokogiri templates.

The idea originated creating a web service with Sinatra.
Quite often I find myself working with JSON responses (especially now that is the de-facto standard for AJAX script) and I found very useful to be able to write JSON templates like you can do with Builder.

I used Yajl because it's very efficient and, as a bonus, .yajl extension is not confusing like .json would be for a template file containing Ruby code.

[weppos]

This template works pretty well, but I just noticed a possible gotcha.

The template assumes the last statement is the "data" you want to convert to json. It might probably be a good idea to have a json buffer so that you can append elements, iterate or change the value as you wish without relying on "the last statement".

I'll experiment a little bit to see if it makes sense.

[judofyr]

What about wrapping it in something like this?

_json = (#{data}); defined?(json) ? json : _json

[rkh]

👍 This would be awesome with sinatra-respond-with.

[weppos]

Hi @rkh,
thanks for stopping by. You're right, this is one of the reasons why I created this patch.

Before I forgot to do that, thanks for the huge amount of sinatra- resources and plugins you are actively maintaining. :)

[weppos]

I made a small refactoring in order to use a buffer variable (the gotcha is now fixed) and added some documentation.

[weppos]

It makes sense. I updated the code. All tests pass.
Any chance to get it merged into the mainstream repo? Do you believe this patch can be useful?

[rkh]

I'm all for including it.

[rtomayko]

Hmm. I like it. It's non-invasive by taking only the .yajl extension (instead of .json or whatever). I'm not sure I like the idea of new template engines being built directly into tilt as opposed to gaining some following / usage as a separate lib and then being folded in. Let's see what happens.