React Conditional Render and Navbar

Question

I am controlling what component should be shown on my applications screen via the state and a switch statement in the main render function. I am writing this in react-native but this is a react structure question.

I also have a Navbar component that I would ideally like to only rerender when the user clicks on a link in the Navbar itself, but I don't know of a great way to do this with how I have the switch statement setup now, it seems like I will have to rerender the Navbar every time depending on what condition is met by the state.

My question is, is there a way that I can still use conditional rendering of components in the render method like I am below AND have a component that is always rendered at the top of the screen like the Navbar? I know this is possible with things like React Router, but is there a better way to structure it without using a tool like React Router or having to rerender the NavBar component every time?

 import React from 'react'; import GPS from './GPS/gps'; import Home from './Home'; import Photo from './Camera/Photo'; export default class App extends React.Component { constructor() { super(); this.state = { hasCameraPermission: null, type: Camera.Constants.Type.back, currentView: null, currentImage: null, navigation: 'Overview' }; this.updateNavigation = this.updateNavigation.bind(this); } updateNavigation(view) { //Update view function this.setState({currentView: view}); } render() { const { currentView } = this.state; switch(currentView) { case null: return ( <Home updateNav={this.updateNavigation} /> ); break; case 'GPS': return ( <View> <GPS /> <Text onPress={() => this.setState({currentView: null})}>Back</Text> </View> ); break; case 'Camera': return ( <Photo updateNav={this.updateNavigation} /> ); break; case 'viewPicture': return ( <View> <Image source={{uri: this.state.currentImage.uri}} style={{width: this.state.currentImage.width/10, height: this.state.currentImage.height/12}} /> </View> ); break; } } } 

Answer 1

Always keep render as much as clean.

You can use && operator to do the same instead of using switch case. Use && operator and check every case and render accordingly. Check below code for better understanding.

render() {
    const { currentView } = this.state;
    return(
      {currentView == null && (
        <Home updateNav={this.updateNavigation} />
        )}
      {currentView == "GPS" && (
        <View>
          <GPS />
          <Text onPress={() => this.setState({currentView: null})}>Back</Text>
        </View>
        )}

      {currentView == "Camera" && (
        <View>
          <Photo updateNav={this.updateNavigation} />
        </View>
        )}

      {currentView == "viewPicture" && (
        <View>
          <Image source={{uri: this.state.currentImage.uri}} style={{width: this.state.currentImage.width/10, height: this.state.currentImage.height/12}} />
        </View>
        )}
    )

  }