Moving form to required

[spiffyjr]

because of https://github.com/zendframework/zf2/blob/develop/library/Zend/Mvc/Service/ServiceListenerFactory.php#L90

[coveralls]

Coverage remained the same when pulling b66d821 on spiffyjr:patch-4 into 22554c4 on zendframework:develop.

[danizord]

@spiffyjr Zend\Form should be optional since you can create the ServiceListener with a custom factory.

[spiffyjr]

Yes, you can, but the default (i.e., the one 99.9% of people will use) includes the form. Technically it's not a dependency but having to write a new factory to avoid using it is wrong, imo.

We should include dependencies to make the component run by default or remove the extra dependencies that aren't required by default.

[weierophinney]

We should include dependencies to make the component run by default or remove the extra dependencies that aren't required by default.

The latter (remove those that are not required by default) is where we've been heading.

MVC is a difficult one, as, technically, you can substitute your own service manager implementation if you want, making the requirements actually quite lean. I'm trying to figure out a way we can address this better, to be honest, as I want to make it clear what is needed at the most basic level, and what we require for the default implementation -- which are two separate things.

[weierophinney]

@spiffyjr My point is that Form is not technically a required component. However, the default implementation of the MVC does require it. Let's address that dichotomy instead.

[spiffyjr]

@weierophinney that's my recommended solution as well but needs to be addressed for more components than just MVC (although MVC is a big offender).

Thanks!

[weierophinney]

@spiffyjr Actually, I merged a PR late last week that addressed a lot of this: #4584