快递中的连锁请求

Question

我需要创建以下过程.我有两个端点,我需要将第二个端点传递给expressejs中第一个端点的结果.我曾想过制作像导游节目一样的东西:

var cb0 = function (req, res, next) {
  console.log('CB0');
  next();
}

var cb1 = function (req, res, next) {
  console.log('CB1');
  next();
}

var cb2 = function (req, res) {
  res.send('Hello from C!');
}

app.get('/example/c', [cb0, cb1, cb2]);

我应该如何将第一个函数传递给第二个函数？

Answer 1

你需要为req参数创建新属性

var cb0 = function (req, res, next) {
  // set data to be used in next middleware
  req.forCB0 = "data you want to send";
  console.log('CB0');
  next();
}

var cb1 = function (req, res, next) {
  // accessing data from cb0
  var dataFromCB0 = req.forCB0

  // set data to be used in next middleware
  req.forCB1 = "data you want to send";
  console.log('CB1');
  next();
}

var cb2 = function (req, res) {
  // accessing data from cb1
  var dataFromCB2 = req.forCB1

  // set data to be used in next middleware
  req.forCB2 = "data you want to send";
  res.send('Hello from C!');
}

app.get('/example/c', [cb0, cb1, cb2]);