9.0: TASK: Simplify command handler resolution

[bwaidelich]

Replaces the explicit if/elseif blocks by simple checks
for a corresponding handle* method

[skurfuerst]

@bwaidelich I personally find the explicit if/else more explicit, so that would be my slight preference; but I'm also totally fine merging this change :) whatever you prefer!

(Especially because then, PHPStorm/PHPStan won't detect the method calls as uncalled; but can statically typecheck them - which won't work with this magic, or am I wrong?)

[bwaidelich]

@skurfuerst I turned all the handle* methods private now (some weren't yet) and added some @noinspection PhpUnusedPrivateMethodInspection annotations to satisfy the IDE.
But I get your point and, yes, it won't be statically type-checked like this.

Maybe there's a third option to get rid of the large amount of repetition like:

And IMO we should go for a single approach (not use if/else in one handler, and match in others).

What about this:

public function canHandle(CommandInterface $command): bool
{
    return method_exists($this, 'handle' . (new \ReflectionClass($command))->getShortName());
}

public function handle(CommandInterface $command, ContentRepository $contentRepository): EventsToPublish
{
        return match ($command::class) {
            SetNodeProperties::class => $this->handleSetNodeProperties($command, $contentRepository),
            // ...
        }
}

[bwaidelich]

@skurfuerst I like that final version now, what do you think?

[skurfuerst]

really nice :) let's get this in!