node.js - Expressjs 中的链式请求

Question

我需要创建以下流程。我有两个端点，我需要将expressejs中第一个端点的结果传递到第二个端点。我想过做一些像指南所示的东西:

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产生的结果传递给第二个函数？

Answer 1

您需要创建新属性来请求参数，例如

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]);