Hoping that issue https://github.com/mongoid/mongoid/issues/1756 would fix my issue, but this is not the case.

I can confirm that MONGOID-1757 does fix the as_json calls for embedded docs, but once they get passed to #render, embedded docs do not seem to produce their as_json in the output. The root doc will produce the as_json override, but the embedded docs do not when using rails #render on rails 3.1.4 (also tried latest 3.2.x branch).

This was not the behavior on mongoid 2.3.x.

for example:

1. Produces the correct output for the embedded docs
   p out.as_json

1. Once it's rendered, only the root respects the as_json override, the embedded docs are not respected.
   render json: out