CodeIgniter 4 Proposed Roadmap

Great news.

Do you guys have any idea on how the upgrade path will work from the 3.x branch? I imagine with the massive changes coming, it will be more than just replacing the system directory.

That is unclear at the moment. It is likely that the changes will be big enough that a smooth upgrade path is unlikely. However, some of the users here on the forums have brought up the idea of a compatibility layer, so it's always possible that something will happen along those lines, unofficially, but I can't really say. At this moment, the priority is getting it actually built and, in this one particular version, backwards compatibility is not a priority. Making the best new version of CodeIgniter is. Of course, this issue will be in our minds as we develop, but as has been mentioned by others here, there comes a time when you need to do a BC-breaking version. For us, that is now. Then we can have a smooth ride for a long time after this.

When you plan to make public the new builds ?
After there is full Alpha version of CI 4 or earlier?

I believe that many people are ready to contribute to it.
But that will be possible only when there are public builds.

I personally think that public builds (trunks - even before first alpha) of the new code will help it to become better.

Yes, code will be out and visible prior to an alpha. We were discussing this issue last week, actually, and are still working out the best way/time to do this. While we welcome community help, we feel that we must get to a certain point in that development where things have crystallized enough in our minds, and in the code, to know how core pieces work together. Otherwise we will likely see many "issues" posted that are simply due to a portion of the code being incomplete, or in flux as we test different implementations, etc.

We are glad you're excited and want to help out, and will welcome that - after we get a little bit of progress done. We haven't started coding yet, so give us a chance to get organized.

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