Can't find variable: navigate

Question

I am trying to navigate between two screen with the help of react-navigation. I am able to access navigate inside the render method as

Answer 1

That happens because you are not destructuring it from the props as you have done in your render() function

onPressButton = () => {
    var {navigate} = this.props.navigation;
    var options = {
      title: strings.app_name,
      content: strings.create_message,
      positiveText: strings.OK,
      onPositive: () => navigate("DashboardScreen")
    };
    var dialog = new DialogAndroid();
    dialog.set(options);
    dialog.show();
  }

Answer 2

Object destructuring work like this,

Destructuring objects:

const obj = { first: 'Jane', last: 'Doe' };
const {first: f, last: l} = obj;
    // f = 'Jane'; l = 'Doe'

// {prop} is short for {prop: prop}
const {first, last} = obj;
    // first = 'Jane'; last = 'Doe'

In Your Case:

1. const { navigation:navigate } = this.props;

or:

2. const {navigation} = this.props;





export default class CreateMessageScreen extends Component {
  render() {  
 const { navigation:navigate } = this.props;

    return (
      <View style={styles.container}>
        <Image source={require("./img/create_message.png")} />
        <Text style={styles.textStyle}>{strings.create_message}</Text>

        <RoundButton
          textStyle={styles.roundTextStyle}
          buttonStyle={styles.roundButtonStyle}
          onPress={this.onPressButton}
        >
          CREATE MESSAGE
        </RoundButton>

      </View>
    );
  }



    onPressButton() {
  const { navigation:navigate } = this.props;
        var options = {
          title: strings.app_name,
          content: strings.create_message,
          positiveText: strings.OK,
          onPositive: () => navigate("DashboardScreen")
        };
        var dialog = new DialogAndroid();
        dialog.set(options);
        dialog.show();
      }
    }

Answer 3

You need to move const { navigate } = this.props.navigation; into the onPressButton function instead of the render function (don't forget to bind the function so that this has the correct value):

export default class CreateMessageScreen extends Component {
  constructor() {
    super();

    // need to bind `this` to access props in handler
    this.onPressButton = this.onPressButton.bind(this);
  }

  render() {  
    return (
      <View style={styles.container}>
        <Image source={require("./img/create_message.png")} />
        <Text style={styles.textStyle}>{strings.create_message}</Text>

        <RoundButton
          textStyle={styles.roundTextStyle}
          buttonStyle={styles.roundButtonStyle}
          onPress={this.onPressButton}
        >
          CREATE MESSAGE
        </RoundButton>

      </View>
    );
  }

  onPressButton() {
    const { navigate } = this.props.navigation;

    var options = {
      title: strings.app_name,
      content: strings.create_message,
      positiveText: strings.OK,
      onPositive: () => navigate("DashboardScreen")
    };
    var dialog = new DialogAndroid();
    dialog.set(options);
    dialog.show();
  }
}