SimpleApplicationFactory

[asgrim]

Q	A
Documentation	yes
Bugfix	no
BC Break	no
New Feature	yes
RFC	yes
QA	no

Description

This PR adds a new factory \Mezzio\Container\SimpleApplicationFactory, and documentation alongside the feature. As discussed in TSC chat, my aim is to simplify creation of an Application instance, such that it is comparable with other similar frameworks. In order to do so, of course we need to make some assumptions here, which I've tried to list.

Note: I don't consider this PR ready to merge; I'd like to open a discussion on how flexible we want to make this and what the best way is; but we should carefully consider each trade-off for making configurable vs simplicity out the box.

Original basis for this: gist 1 gist 2.

[Xerkus]

@asgrim may be it would make more sense as another lightweight skeleton package instead?

[Ocramius]

I wonder if a full dispatch wouldn't be a better scenario here

[asgrim]

It's possible, but a LOT of work, since we've made many things "unmockable" here (intentionally, it's a factory that makes assumptions); so things like \Laminas\Diactoros\ServerRequestFactory::fromGlobals become a bit more tricky. Not sure it's worth the effort here?

[weierophinney]

Added a few nitpicks.

I tend to agree with @froschdesign and @Ocramius that "Minimal" would be better here. We may consider it "simple", but somebody not as familiar with interfaces, containers, and whatnot might not!

One more point I'd make: the container is used internally primarily to pull middleware and handlers that have been piped/routed by name instead of by _instance. With a minimal setup like this, is it terribly useful? Could we not just provide an anonymous PSR-11 implementation?

Additionally, we may want to consider, in the future, adding tooling to migrate a minimal app to a skeleton. But you can ignore that comment for now. :)

[boesing]

Should we considering some "minimal" application factory around https://github.com/php-http/discovery?

I dont like the magic of php-http/discovery but as of this PR, I would rather use that library instead of depending on assumptions that laminas-diactoros is installed which might not be true.

As @Xerkus stated, this could be done in a pretty simple component which just adds the new MinimalApplicationFactory and has a dependency on php-http/discovery.

Thus, there is no need for all that other stuff (but, yes, there would be a new component and its not as simple as this PR anymore).

---

Sadly, there is no "magic" library which can autodiscover containers. Thats where the upcoming laminas-container-contracts package might become handy? @weierophinney thoughts?

[asgrim]

One more point I'd make: the container is used internally primarily to pull middleware and handlers that have been piped/routed by name instead of by instance. With a minimal setup like this, is it terribly useful? Could we not just provide an anonymous PSR-11 implementation?

I'm unclear what you mean here @weierophinney ? In my clients application where I'm using this (or rather, the basis of this), I use the container to assign to the pipeline, e.g.:

$container = new ServiceManager();
$container->setFactory(MyMiddleware::class, /** stuff */);
$container->setFactory(MyHandler::class, /** stuff */);

// -- later .... .... -

$app->pipe(MyMiddleware::class);
$app->get('/best-url', MyHandler::class, MyHandler::class);

If I understand what you're saying, this wouldn't be possible I think?

[asgrim]

I dont like the magic of php-http/discovery but as of this PR, I would rather use that library instead of depending on assumptions that laminas-diactoros is installed which might not be true.

It is indeed an assumption; but if Diactoros is not installed, it'll be fairly obvious why, since autoloading will complain about missing dependencies in Laminas\Diactoros. It is a trade-off indeed, hence why I put to others to consider :)

[weierophinney]

I'm unclear what you mean here @weierophinney ? In my clients application where I'm using this (or rather, the basis of this), I use the container to assign to the pipeline, e.g.:

Okay - I wasn't clear that you intended to allow that usage, from the examples you provided (which all involved creating an empty container)! I'm fine with leaving as-is, then.

[weierophinney]

I dont like the magic of php-http/discovery but as of this PR, I would rather use that library instead of depending on assumptions that laminas-diactoros is installed which might not be true.

It is indeed an assumption; but if Diactoros is not installed, it'll be fairly obvious why, since autoloading will complain about missing dependencies in Laminas\Diactoros. It is a trade-off indeed, hence why I put to others to consider :)

I think the whole idea of this is to be as opinionated as possible, to provide a "works-out-of-the-box" solution.

With that said: I wonder if this might be an argument for having a separate package for this factory? It could then explicitly list those requirements, and users would do something like:

$ composer require mezzio/mezzio-minimal
$ ./vendor/bin/laminas mezzio:minimal:create index.php # creates a template for a minimal install in the index.php file
$ vim index.php # edit the file to add routes
$ ./vendor/bin/laminas mezzio:minimal:serve -p 8080 -h 127.0.0.1 # fire it up

Thoughts?

[asgrim]

I dont like the magic of php-http/discovery but as of this PR, I would rather use that library instead of depending on assumptions that laminas-diactoros is installed which might not be true.

It is indeed an assumption; but if Diactoros is not installed, it'll be fairly obvious why, since autoloading will complain about missing dependencies in Laminas\Diactoros. It is a trade-off indeed, hence why I put to others to consider :)

I think the whole idea of this is to be as opinionated as possible, to provide a "works-out-of-the-box" solution.

With that said: I wonder if this might be an argument for having a separate package for this factory? It could then explicitly list those requirements, and users would do something like:

$ composer require mezzio/mezzio-minimal
$ ./vendor/bin/laminas mezzio:minimal:create index.php # creates a template for a minimal install in the index.php file
$ vim index.php # edit the file to add routes
$ ./vendor/bin/laminas mezzio:minimal:serve -p 8080 -h 127.0.0.1 # fire it up

Thoughts?

I'd be interested in taking that on, sure. I'll put together a prototype repo on my own GitHub and loop back here. Great ideas folks, thank you all.

[asgrim]

OK folks; I've moved this to https://github.com/asgrim/mini-mezzio now 👍

Thoughts/issues/suggestions/PRs are welcome there 😁

Closing this now.