Flat/flex-buffers Type Definition (FTD?)

[ramblehead]

I have been playing with flatbuffers for a few months now using it as a generic RPC/IPC format (not only gRPC).

It is a great project - thank for developing it and making it open source!

When implementing RPC in fbs, I almost immediately encountered couple of issues:

1. Need to access fbs schema programmatically for: higher-level code-generation from outside C++ (e.g. from Python); and for RPC service introspection.
2. Need to somehow describe and validate flexbuffers.

As a first attempt I implemented idl_gen_jtd.cpp (using idl_gen_json_schema.cpp as an example) - most langs support JSON and many JDT out of the box, so it solves both issues above. To validate flexbuffer with jtd - it needs to be converted to JSON first.

JDT solution seems a regression as it requires going back to JSON from flatbuffers for introspection and validation. It should be feasible to implement flatbuffers schema that describes flat/flex-buffers schema (similar to JDT). Is there some document or project that defines flatbuffers schema in flatbuffers format?

[aardappel]

Is there some document or project that defines flatbuffers schema in flatbuffers format?

yup we have exactly that, the .bfbs format (binary flatbuffers schema), which is actually a FlatBuffer itself, and using reflection/reflection.fbs can be read in any language. See also --schema here: https://google.github.io/flatbuffers/flatbuffers_guide_using_schema_compiler.html

[ramblehead]

Thank you for your reply! I missed --schema option and reflection/reflection.fbs capabilities. It is much better than what I hoped for.