defaultProps in React Native?

Question

Is it possible to use defaultProps in React Native? I’ve tried the following 2 ways of defining defaultProps and I get null when trying to access the defaultProp

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Answer 1

I do it in ReactNative

import React, {
    Component
} from 'react';
import {
    View,
    Text
} from 'react-native';
import PropTypes from 'prop-types';

export default class foo extends Component {
    static propTypes = {
        name: PropTypes.array,
        prop2: PropTypes.string
    }
    static defaultProps = {
        array: [1, 2, 4],
        name: 'abc'
    }
    constructor(props) {
        super(props);
        this.state = {};
    }
    render() {
        return (
            <View>
                <Text>Default Prop array is: {this.props.array}</Text>
                <Text>Default Prop name is: {this.props.name}</Text>
            </View>
        );
    }
}

And then you can use these props like this.props.prop1 and this.props.prop2.

Answer 2

You want this:

Foo.propTypes = {
    someData: React.PropTypes.string
};

This says that someData should be a string, but it is not required.

Then in your render(), you can do this:

render() {
    return (
      <View> 
        {this.props.someData || Foo.defaultProps.someData} 
      </View>
    );
  }

This will use this.props.someData if it's provided or Foo.defaultProps.someData if not.

I also think you need to wrap {this.props.someData || Foo.defaultProps.someData} in a Text element (i.e., <Text>{this.props.someData || Foo.defaultProps.someData}</Text>).

Answer 3

I always do it like this and it works just fine:

class Foo extends React.Component {};

Foo.propTypes = {
  animateBackground: PropTypes.bool
};

Foo.defaultProps = {
  animateBackground: false
};

export default Foo;