adr VS Tutorial-First-Application

This is one of the questions Action Domain Responder seeks to answer. The answer for Actions in ADR is the same answer as for a Controller action method in MVC.

First, this is an excellent question. But to answer it, we need to define some terms. Do you mean "action" as in ADR, where the action class is what would have been a controller action method (aka "single-action controller")? Or do you mean "action" as the Laravel folks often use it, a la https://laravelactions.com/ ?

With that in mind, MVU strikes me as being a lot like Action Domain Responder. (I've not heard of MVU before.)

Oh sorry, it means Action Domain Responder, it's a design pattern akin to MVC ( and it's nuances like MVVC ) or DDD. This is the blog of Jones, the person who coined that pattern : http://pmjones.io/adr/

ADR (as opposed to MVC) - direct link - example

Contra /u/dave8271 below, I think it does matter. There are many different ideas about MVC, and as such it's not a very clear vocabulary term, esp. on the server side. The Action Domain Responder pattern exists to help clarify some of those distinctions.

At first I read this as (my paper on) ADR vs MVC. You may wish to consider the ADR pattern over MVC for an API system.

Ah, thanks for saying! As far as one class per route, it's more in line with Action Domain Responder than with what we usually think of as MVC.

This is it: https://github.com/pmjones/adr/blob/master/MVC-MODEL-2.md

cough Action Domain Responder cough

b) Separate out all SQL and PHP database code. Put these in separate classes similar to this example Slim First Application Mapper class. You can decide later if you want to use a framework's DB code or not - it would be simply refactoring your existing code and not changing (hopefully) the API that you started using internally

Yes, as an example, the First Application's business logic (not that it's much) doesn't tie itself to the framework, as one example. Odan's Slim Skeleton, ADR Example (yes, I know you are the author), and the Aura Payload example class can be seen as other examples.

Both. Build business logic with PHP, then use a framework for the common functionality (routing, auth, validation, etc). Look at Slim's First Application to show a very simple example of this - https://github.com/slimphp/Tutorial-First-Application

Another option, to me and speaking to the OP as an alternative, it is simpler to add some Data Mappers/Repositories to abstract away the Database code. Good examples is the sample ADR application, Payload library example, Slim 3 First Application, or this Slim 4 Skeleton application

Yes, you can. Did you look at the example I provided? Want another one? Slim Framework's first application does exactly this:

https://github.com/slimphp/Tutorial-First-Application <- Uses the Slim framework