Dismiss modally

[RuiAAPeres]

What's in this PR

This idea originated from a conversation with @dmcrodrigues, where things like popToRootViewController and other ways of manipulating the UI flow, always end with a side effect ( startWith and observe methods family). This PR an attempt to make these situation, more idiomatic and declarative.

API

Currently it's using MutableProperty<(Bool, (Void -> Void)?)?>, the Bool is for the Animated flag and the (Void -> Void)? for the completion closure. I make the whole tuple an optional to address the initial value of a MutableProperty (in this case the initial value is nil).

So I would appreciate some feedback on it. cc @mdiep @iv-mexx

How to use it

Currently one would do the following:

producer.startWithNext { [weak self] _ in
   self?.dismissViewControllerAnimated(true, completion: nil)
}

With this PR:

self.rex_dismissModally <~ producer.map { _ in (true, nil) } // where `true` is for the `Animated` flag and `nil` for the completion closure

Caveat (Help needed)

There also the cases where one wants to observe the dismiss of a UIViewController:

viewController.rex_dismissModally.signal.observeNext { _ in

}

via:

viewController.dismissViewControllerAnimated(true, completion: nil)

I wasn't able to make this work. I tried the following:

let property = associatedProperty(self, key: &dismissModally, initial: initial, setter: setter)

property <~ rac_signalForSelector(#selector(UIViewController.dismissViewControllerAnimated(_:completion:)))
            .rex_toTriggerSignal()
            .map { _ in nil }

return property

This will actually break the test, but it will make the viewController.dismissViewControllerAnimated(true, completion: nil) work.

Edit1: This seems to be fixed on c015b96

[RuiAAPeres]

Adding in @ikesyo for feedback.

[RuiAAPeres]

c015b96 fixes the issue! You can now observe both:

viewController.rex_dismissModally <~ SignalProducer(value: (true, nil))

viewController.dismissViewControllerAnimated(true, completion: nil)

[dmcrodrigues]

I like the ideia and seems something that can be quite useful.

However, I would suggest two small changes:

• changing the name to something like rex_ dismissViewControllerAnimated or rex_dismissAnimated, I think that rex_dismissModally doesn't indicate clearly and easily the operation being performed behind the scenes;
• naming tuple's parameters to make it more explicit, e.g. SignalProducer(value: (animated: true, completion: nil)).

In case of positive feedback we can adopt this approach to other operations like UINavigationControllers's popViewControllerAnimated and many others.

[RuiAAPeres]

@dmcrodrigues pushed with rex_dismissAnimated naming, since the method belongs to the UIViewController class.

[dmcrodrigues]

Maybe we can be explicit about the parameters of the tuple (sometimes tests are used as usage reference).