__layout.hbs

{{! APPDIR/app/templates/__layout.hbs }}

<script>
(function() {
  var App = window.App = new (require('app/app'))({{json appData}});
  App.bootstrapData({{json bootstrappedData}});
  App.start();
})();
</script>

server.js

// APPDIR/server/server.js

function initMiddleware() {
  app.configure(function() {
    // set up views
    app.set('views', __dirname + '/../app/views');
    app.set('view engine', 'js');
    app.engine('js', rendrServer.viewEngine.render);

    // set the middleware stack
    app.use(express.compress());
    app.use(express.static(__dirname + '/../public'));
    app.use(express.logger());
    app.use(express.bodyParser());
    app.use(app.router);
    app.use(mw.errorHandler());
  });
}

viewEngine.js

//rendr/server/viewEngine.js

// http://expressjs.com/api.html#app.engine
// viewPath = '/Users/a598063/Sites/consumer-analytics-demos/app/views/maps/index.js'
// data = { settings: {}, locals: {'our prefetched data, if there is any'}, app: {}, req: {}, ...}
// callback = 
//    res.render(viewPath, viewData, function(err, html) {
//    if (err) return router.handleErr(err, req, res);
//      res.set(router.getHeadersForRoute(route));
//      res.type('html').end(html);
//    });
// from rendr/server/router.js ServerRouter.prototype.getHandler

ViewEngine.prototype.render = function render(viewPath, data, callback) {
  var app, layoutData;

  data.locals = data.locals || {};
  app = data.app;
  layoutData = _.extend({}, data, {
    body: this.getViewHtml(viewPath, data.locals, app),
    appData: app.toJSON(),
    bootstrappedData: this.getBootstrappedData(data.locals, app),
    _app: app
  });
  this.renderWithLayout(layoutData, app, callback);
};