api-fetch.js

var router = Router.create({
    routes,
    location,
    onAbort: function defaultAbortHandler(abortReason) {
        reject(abortReason);
    }
});


router.run(function (Handler, State) {
    (function() {
        var data = {};
        return when.Promise.all(State.routes
            .filter(route => route.handler.load_data)
            .map(route => {
                return route.load_data.fetch(State).then(d => {
                    data[route.name] = d;
                });
    }))).then(() => data).then((data) => {
        var appHtml = React.renderToString(<Handler data={data} />);

        if (State.routes[State.routes.length-1].name == 'not-found') {
            reject(new NotFoundResponse(appHtml));
        } else {
            resolve(appHtml);
        }
    });
});