App.js

const App = React.createClass({
    render() {
        var page = this.props.currentPage;
        return <div>
            {page}
        </div>;
    }
});

LoginPage.js

// Version 1
const LoginPage = React.createClass({
    render() {
        return <div>
            <h1>Login</h1>
            <Login
                loading={pageProps.loginLoading}
                errorMessage={errorMessage}
                dismissError={this._dismissError}
                onSubmit={this._onSubmitLogin} />
        </div>;
    }
});


// Version 2
// Sometimes it would be nice to do this instead, because I know there will be 
// a wrapper div at App level

const LoginPage = React.createClass({
    render() {
        return [
            <h1>Login</h1>
            <Login
                loading={pageProps.loginLoading}
                errorMessage={errorMessage}
                dismissError={this._dismissError}
                onSubmit={this._onSubmitLogin} />
        ];
    }
});