In JavaScript, the value of this
changes depending on the current context. Within React class component methods, developers normally expect this to refer to the current instance of a component, so it is necessary to bind these methods to the instance. Normally this is done in the constructor—for example:
class SubmitButton extends React.Component {
constructor(props) {
super(props);
this.state = {
isFormSubmitted: false
};
this.handleSubmit = this.handleSubmit.bind(this);
}
handleSubmit() {
this.setState({
isFormSubmitted: true
});
}
render() {
return (
<button onClick={this.handleSubmit}>Submit</button>
)
}
}