[cdi-dev] This is StillDI

[Ladislav Thon <lthon@xxxxxxxxxx>]

Hi,

over last weeks, I've heard many people expressing a concern that what 
we're up to with CDI Lite, and especially with the new extension model, 
is "no longer CDI". I'm 100% sure that isn't anyone's intention, it 
certainly isn't mine.

On one of the recent CDI calls, I realized (again thanks Tomas Langer 
for the initial idea) that it's probably possible to implement the 
proposed Build Compatible Extensions API on top of existing Portable 
Extensions, proving that indeed this is still CDI, and indeed this can 
still be made a strict subset of CDI with a little help.

Here goes: https://github.com/Ladicek/StillDI

Note that the README isn't really meant to be end-user documentation. 
It's meant for CDI experts and mainly serves as a brief overview and a 
comparison between the 2 extension APIs.

As part of the work, I discovered a few discrepancies that we need to 
resolve, and fortunately, they are all really small. Specifically:

1. The proposed Build Compatible Extensions API allows adding all 
subtypes of a given type to be scanned during bean discovery. Portable 
Extensions don't have that, and I think we should just remove this. The 
method to add one concrete type is obviously not an issue.

2. The proposed Build Compatible Extensions API allows setting a 
priority of a synthetic bean (together with its "is alternative" flag). 
I propose we add this to Portable Extensions.

3. The proposed Build Compatible Extensions API provides access to the 
"current" injection point when creating an instance of a synthetic bean, 
when its scope is @Dependent. This is possible with producer methods, so 
I don't see why it shouldn't be possible with synthetic beans. I propose 
we add this to Portable Extensions.

Other than that, I don't see anything that can't be losslessly 
translated between the 2 extension APIs, even though they are somewhat 
differently structured at certain places. (We might also want to align 
that structuring more, that is all open for debate.)

I'd be grateful for any kind of comments, preferrably here on this 
mailing list I guess (but don't really mind).

Thanks,

LT