In ES2015 a.k.a ES6, class is a syntactic sugar for functions.
If you want to force to set a context for this you can use bind() method. As @chetan pointed, on invocation you can set the context as well! Check the example below:
class Form extends React.Component {
constructor() {
super();
}
handleChange(e) {
switch (e.target.id) {
case 'owner':
this.setState({owner: e.target.value});
break;
default:
}
}
render() {
return (
<form onSubmit={this.handleNewCodeBlock}>
<p>Owner:</p> <input onChange={this.handleChange.bind(this)} />
</form>
);
}
}
Here we forced the context inside handleChange() to Form.