Example of context in react.tsx

import * as React from 'react';
import * as ReactDOM from 'react-dom';
import * as PropTypes from 'prop-types';

const styleObj = PropTypes.shape({
    color: PropTypes.string,
    fontSize: PropTypes.number
});

interface ButtonProps {
    label: string;
}

class Button extends React.Component<ButtonProps, {}> {
    static contextTypes: any = {
        'style': styleObj
    };

    handleClick = () => {
        alert('click');
    }

    render() {
        return (
            <button
                className="btn btn-default"
                onClick={this.handleClick}
                style={{
                    'fontSize': this.context.style.fontSize + 'px',
                    'color': this.context.style.color
                }}>
                {this.props.label}
            </button>
        );
    }
}

class MyApp extends React.Component<{}, {}> {
    static childContextTypes: any = {
        'style': styleObj,
    };

    getChildContext() {
        return {
            style: {
                color: 'blue',
                fontSize: 20
            }
        };
    }

    render() {
        return (
            <div>
                <Button label={"click me"} />
                <Button label={"but also click me"} />
                <Button label={"click me"} />
            </div>
        );
    }
}

ReactDOM.render(
    <MyApp />,
    document.getElementById('content')
);