Document how to render conditional child navigation

Hi. In my team we’ve struggled to implement conditional child navigation, where a branch of the navigation depends on user data (e.g. data in Redux and/or received from an API). In pseudo-code:

const Section1Default = StackNavigator(/* Some screens */)
const Section1Onboarding = StackNavigator(/* Different screens */)

const RootNavigator = TabNavigator({
  section1: Section1Default OR Section1Onboarding,
  section2: …,
  section3: …
})

The idea is that when clicking on a specific tab, the user should see either a series of "onboarding" screens or the feature’s screens. (Both options are navigators themselves, but could be single screens too.)

@brentvatne & @ericvicenti Do you think that’s a use case worth addressing in the docs?
I think I could contribute a page section or a page on this, but I’m not sure what solution to offer.

So far we’ve only found hackish workarounds, such as: a wrapper component which has a StackRouter with the two navigation branches, and which navigates to the correct branch on willFocus. It works, but the trick falls short when using the Android back button.

未指定文档文件、测试或入口点。首先检查现有的导航文档和报告中的 wrapper 组件变通方案，然后验证条件子导航器如何与 Android 返回按钮交互。完成的标准是记录一种经认可且受支持的模式，用于根据用户数据选择 onboarding 或功能导航。