CODEWITHSUNDEEP
reactjsreact-nativereact-navigation
peter
peter

Reputation: 1572

Pass function into React Navigation's headerTitle component

I'm trying to implement a deletePost button, but I'm struggling to pass it into my header component. Here's the 

export class PostScreen extends Component {


  // Custom headerTitle component.
  static navigationOptions = ({ navigation }) => {
    const { params } = navigation.state;
    return { headerTitle: <PostTitle {...params} handleDelete={this.handleDelete}/> }
  };

  handleDelete = async (id) => {
    const { deletePost } = this.props;
    const token = await AsyncStorage.getItem('token');
    deletePost(token, id);
  }

render() {

This does'nt seem to be the right way to pass it in. What's the correct way? I can't find anything in the docs.

Upvotes: 3

Views: 7654

Answers (2)

Cho Cho
Cho Cho

Reputation: 157

in your component did mount use an arrow function as below and the function won't be called when the component first mount.

componentDidMount() {
    this.props.navigation.setParams({ handleDelete: (() => this.handleDelete()) 
});

Upvotes: 0

Andrew
Andrew

Reputation: 28539

As you are using react-navigation then this is how you set a function in the header component.

  1. You have to define the function in your class
  2. In your componentDidMount set the function as a param using setParam
  3. Use getParam in your navigation header.

This is how it would look in a very simple component.

export default class Screen1 extends React.Component {

  static navigationOptions = ({ navigation }) => {
    const { params } = navigation.state; // this is included because you had added it and you may require the params in your component
    return {
      headerTitle: <PostTitle  {...params} handleDelete={navigation.getParam('handleDelete')} />, // grab the function using getParam
    };
  };

  handleDelete = () => {
    alert('delete')
  }

  // set the function as a param in your componentDidMount
  componentDidMount() {
    this.props.navigation.setParams({ handleDelete: this.handleDelete });
  }


  render() {
    return (
      <View style={styles.container}>
        <Text>Screen1</Text>
      </View>
    )
  }
}

Then in your PostTitle component you can use the function that you just passed by calling this.props.handleDelete

Here is a snack that shows the basic functionality https://snack.expo.io/@andypandy/functions-in-a-navigation-header

You can read more about setting functions in the navigation header here

Upvotes: 9

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