fix(iOS) pushing a removing screen to controller

[wvq]

Description

Fixes #2559

Bug track:
The logic waiting for the transition complete and then call updateContainer has problem.
An old screen may be about to be removed but has not yet been removed.
which not in _controllers, but _reactSubviews not remove it yet.
updateContainer iterates _reactSubviews and call setPushViewControllers.
The old screen will push again.

This change add a property disappeared to RNSScreen, defaults to NO.

• on viewWillAppear/viewDidAppear/viewWillDisappear set NO
• on viewDidDisappear set YES

In RNSScreenStack's setPushViewControllers, check if it's not an new screen.

if(!((RNSScreen *)top).disappeared) {
  [_controller pushViewController:top animated:YES];
}

[kkafar]

Hey, that looks great, thanks. I'll test that when I have a moment & we'll see how do we proceed here.

[wvq]

@kkafar This fix conflicts with react-navigation's usePreventRemove, should not be approved.
The logic of usePreventRemove is to add disappeared screen again,
This bug is also because add disappeared screen again.
In this repo, there is no way to check if the screen is disappeared and should't add it.
It's need react-navigation passing some neccessary information to check it.

[JustJoostNL]

@wvq So do I understand correctly that, to fix the issue, changes in react-navigation are needed rather than in react-native-screens?

If so, are you planning to do a PR there? I would love to see this fixed. 😄

[wvq]

@JustJoostNL No, the bug is on this project, I just can't find a proper way to mark the expired screen.
my PR is marking expired screen and prevent it add again, it work for my case, not for all.
react-navigation usePreventRemove just an example which not suite.
So I close this PR.

[JustJoostNL]

Ah right. I guess someone has to come up with a global working solution then.

[wvq]

For now, my temporary solution is run hook after npm install.

#!/bin/bash

#
# temporary fix react-native-screens
# 
# https://github.com/software-mansion/react-native-screens/issues/2559
#

check='disappeared'

screen_header='./node_modules/react-native-screens/ios/RNSScreen.h'
screen_mm='./node_modules/react-native-screens/ios/RNSScreen.mm'
screen_stack_mm='./node_modules/react-native-screens/ios/RNSScreenStack.mm'


if ! grep -qw $check $screen_header; then
    sed -i '' '43i\
@property (nonatomic, readonly) BOOL disappeared;\
' $screen_header
fi

if ! grep -qw '_disappeared' $screen_mm; then
sed -i '' '1353i\
    _disappeared = NO;\
' $screen_mm
sed -i '' '1365i\
  _disappeared = NO;\
' $screen_mm
sed -i '' '1393i\
  _disappeared = NO;\
' $screen_mm
sed -i '' '1431i\
  _disappeared = NO;\
' $screen_mm
sed -i '' '1448i\
  _disappeared = YES;\
' $screen_mm
fi


if ! grep -qw $check $screen_stack_mm; then
    sed -i '' '680i\
      if(!((RNSScreen *)top).disappeared) {\
' $screen_stack_mm
sed -i '' '682i\
      }\
' $screen_stack_mm
fi

echo 'hook finished'

[wvq]

This bug is caused by asynchrony, I think some logic may need to be refactored, which is not something that a simple solution can handle.