React.createElement的问题

Question

I'm trying to reproduce this tutorial (it's outdated a bit) and at this place

var html = ReactDOM.renderToString(React.createElement(Router.RouterContext, renderProps));

I'm get this error:

Warning: React.createElement: type should not be null, undefined, boolean, or number. It should be a string (for DOM elements) or a ReactClass (for composite components).

Error triggered by

import createBrowserHistory from 'history/createBrowserHistory';
let history = createBrowserHistory();

ReactDOM.render(
    <Router history={history}>
        {routes}
    </Router>, 
    document.getElementById('app')
);

I'm newbie at React so maybe you can help me?

Answer 1

Right after that sections there is an update:

October 19, 2015 Update: Previous React.renderToString now lives
in the react-dom/server package. Additionally, server-side rendering
with    React Router has changed quite a bit. See Server Rendering
Guide for more details.

It looks like you'll need to set it up according to their Server Rendering Guide.