How to switch subcomponent after render depend on state?

Question

There is three screen thar Index.tsx, Profile.tsx, Login.tsx. I try to going Login to set AsyncStorage then back to Profile use this.state.member get from AsyncStorage to switch components inside Profile. But now I only can go back to index then profile in this way I can change sub component in Profile

I done like this before by using react-navigation createSwitchNavigator(). But now I try to re-render in Profile by using this.setState({member: (result from AsyncStorage.getItem("member") ) ? AsyncStorage.getItem("member") : undefined }) in componentDidMount()

Here's the code of the case, https://gist.github.com/sanhuang/4526dbd00051695c80b7b36dd7230ef8

export default class ProfileSreen extends Component {

  constructor(props) {
    super(props)

    this.state = {
      isLoading: true,
      isSignIn: false,
      member: undefined
    }

    this._getMemberStorage = this._getMemberStorage.bind(this);
  }

  componentDidMount() {
     this._getMemberStorage();
  }

  async _getMemberStorage(): Promise<void> {
    try{
      // let member = null;
      let member = await ExStorage.getItem("member");
      // console.log(member);

      if ( member !== null ){
        await this.setState({
          member,
          isSignIn: true
        });
      }else{
        await this.promisedSetState({
          member: null,
          isSignIn: false
        });
      }
      await this.promisedSetState({
        isLoading: false
      });

      return true;
    }catch(e) {
      console.error(e);
    }
  }

  promisedSetState = (newState) => {
    return new Promise((resolve) => {
      this.setState(newState, () => {
        resolve()
      });
    });
  }

  protected _renderLogin() {
    return (
      <ListItem>
          <Button small rounded
            onPress={() => {
              this.props.navigation.navigate('Profile_Login');
            }}
          >
            <Text>Login</Text>
          </Button>
      </ListItem>
    )
  }

  protected _renderMember() {
    return (
      <ListItem>
        <Body>
          <H2>{this.state.member.cmt} {this.state.member.unit}{this.state.member.name},您好</H2>
          <Text note>xxx</Text>
        </Body>
      </ListItem>
    )
  }


  protected render() {
    let infocoms = null;

    if (this.state.isLoading ) {
      return (
        <L.PageLoading />
      )
    }else{
      if (this.state.isSignIn) {
        infocoms = this._renderMember();
      } else {
        infocoms = this._renderLogin();
      }

      return (
        <Root>
          <Container>
          <Content>
            <List>
              {infocoms}
            </List>

            <Settings />

          </Content>
          {<L.IFooter />}
          </Container>
        </Root>
      );
    }

  }
}

The result always render _renderLogin() even I logined

Gaël S Gaël S · Accepted Answer · 2019-06-15T16:36:58

Do you indeed see that you're getting a valid member value from your login request ?

Besides you don't need to put an await before a setState:

await this.setState({
          member,
          isSignIn: true
        });

That might lead to unexpected things I guess.

How to switch subcomponent after render depend on state?

1 Answers