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.

未指定文件、測試或進入點。首先檢視現有的導覽文件和回報的 wrapper 元件替代方案，然後驗證條件式子導覽器如何與 Android 返回按鈕互動。完成的標準是記錄一種經同意且受支援的模式，用於根據使用者資料選擇 onboarding 或功能導覽。