Focus style for TextInput in react-native

In React Native, how do you change the style of a textInput when it gets focus? Say I have something like

class MyInput extends Component {
    render () {
        return <TextInput style={styles.textInput} />;
    }
};

const stylesObj = {
    textInput: {
        height: 50,
        fontSize: 15,
        backgroundColor: 'yellow',
        color: 'black',
    }
};
const styles = StyleSheet.create(stylesObj);

And I want to change the background color on focus to green.

This documentation leads me to believe that the solution is something like

class MyInput extends Component {
    constructor (props) {
        super(props);
        this.state = {hasFocus: false};
    }

    render () {
        return (<TextInput
            style={this.state.hasFocus ? styles.focusedTextInput : styles.textInput}
            onFocus={this.setFocus.bind(this, true)}
            onBlur={this.setFocus.bind(this, false)}
        />);
    }

    setFocus (hasFocus) {
        this.setState({hasFocus});
    }
};

const stylesObj = {
    textInput: {
        height: 50,
        fontSize: 15,
        backgroundColor: 'yellow',
        color: 'black',
    }
};
const styles = StyleSheet.create({
    ...stylesObj,
    focusedTextInput: {
        ...stylesObj,
        backgroundColor: 'green',
    }
});

Ignoring potential mistakes in the styles structuring, would this be considered correct way to handle it? It seems very verbose to me.

Solution

You can achieve this by passing in the onFocus and onBlur events to set and unset styles when focused and blurred:

  onFocus() {
    this.setState({
        backgroundColor: 'green'
    })
  },

  onBlur() {
    this.setState({
      backgroundColor: '#ededed'
    })
  },

And then, in the TextInput do this:

<TextInput 
    onBlur={ () => this.onBlur() }
    onFocus={ () => this.onFocus() }
    style={{ height:60, backgroundColor: this.state.backgroundColor, color: this.state.color }}  />

I've set up a full working project here. I hope this helps!

https://rnplay.org/apps/hYrKmQ

'use strict';

var React = require('react-native');
var {
  AppRegistry,
  StyleSheet,
  Text,
  View,
  TextInput
} = React;

var SampleApp = React.createClass({

  getInitialState() {
    return {
        backgroundColor: '#ededed',
      color: 'white'
    }
  },

  onFocus() {
        this.setState({
        backgroundColor: 'green'
    })
  },

  onBlur() {
    this.setState({
      backgroundColor: '#ededed'
    })
  },

  render: function() {
    return (
      <View style={styles.container}>
       <TextInput 
        onBlur={ () => this.onBlur() }
        onFocus={ () => this.onFocus() }
        style={{ height:60, backgroundColor: this.state.backgroundColor, color: this.state.color }}  />
      </View>
    );
  }
});

var styles = StyleSheet.create({
  container: {
    flex: 1,
    marginTop:60
  }
});

AppRegistry.registerComponent('SampleApp', () => SampleApp);