(feat) Integrate legacy Luci views inside new Luci-ng app

[ianchi]

In some talks we have agreed that it would be great to have some way to integrate legacy views in the new app, to leverage all the existing extensions.
Quoting some background on #42 from @jow-

My idea here is to build some kind of special legacy LuCI theme which removes header and footer markup but includes some special .js file instead which takes care of rendering the LuCI-NG framing around the legacy content markup. I have already started to convert legacy LuCI to ubus login sessions so that message passing between old and new LuCI becomes easier.

At this stage I am skeptical about how feasible a deeper integration is, like refactoring the old Lua/HTML CBI to output JSON schemas instead as this would require a lot of message-passing with the backend to execute embedded Lua code snippets and expose their inputs/outputs via some RPC channel.

I'm leaving this issue opened to track anything related to this topic

[danielfdickinson]

FYI I have an interest in this 'connector' issue and had planned on working on it in 2016 but (mental) health issues got in the way for a couple of years. I'm wanting to work on this, but I'm not really a frontend developer though I've, out of necessity, done some frontend stuff just to be able to 'get stuff done'. Wondering what exactly the status of luci-ng framework basis is, or if it's gotten stuck. If it's gotten stuck, what are the sticking points? (i.e. is there an issue with some choices made based on what is good on 'normal' servers but don't work out so well (especially for size) on small embedded devices?

Is there much out there that is actually written for small embedded devices in terms of frameworks, etc?

I did see something about JSON definitions to make the choice of 'engine' (framework) independent of what a LuCI app developer would deal with (unless needing a new cabability). Did I read that right, and what is status?