javascript - Node.js/Express - 找不到页面时呈现错误

Question

我在 Node.js 中有以下 Controller /路由定义(使用 Express 和 Mongoose)。当用户请求一个不存在的页面时，处理错误的最简单最合适的方法是什么？

  app.get('/page/:pagetitle', function(req, res) {
      Page.findOne({ title: req.params.pagetitle}, function(error, page) {
          res.render('pages/page_show.ejs',
            { locals: {
                title: 'ClrTouch | ' + page.title,
                page:page
            }
          });
      });
  });

它目前破坏了我的应用程序。我相信因为我没有对错误做任何事情，我只是将它传递给 View ，就像成功一样？

TypeError: Cannot read property 'title' of null

非常感谢。

Answer 1

查看 express error-pages例子。原则是首先注册您的应用程序路由，然后为所有其他未映射到路由的请求注册一个 catch all 404 处理程序。最后注册一个500的handler，如下:

// "app.router" positions our routes 
// specifically above the middleware
// assigned below

app.use(app.router);

// Since this is the last non-error-handling
// middleware use()d, we assume 404, as nothing else
// responded.

app.use(function(req, res, next){
  // the status option, or res.statusCode = 404
  // are equivalent, however with the option we
  // get the "status" local available as well
  res.render('404', { status: 404, url: req.url });
});

// error-handling middleware, take the same form
// as regular middleware, however they require an
// arity of 4, aka the signature (err, req, res, next).
// when connect has an error, it will invoke ONLY error-handling
// middleware.

// If we were to next() here any remaining non-error-handling
// middleware would then be executed, or if we next(err) to
// continue passing the error, only error-handling middleware
// would remain being executed, however here
// we simply respond with an error page.


app.use(function(err, req, res, next){
  // we may use properties of the error object
  // here and next(err) appropriately, or if
  // we possibly recovered from the error, simply next().
  res.render('500', {
      status: err.status || 500
    , error: err
  });
});