中间件的写法
支持 callback1,callback2、[callback1, callback2]、function callback(req, res, next) 或混合写法
function cb1(req, res, next) {
console.log('--cb1--');
next();
}
function cb2(req, res, next) {
console.log('--cb2--');
next();
}
app.get('/',
cb1, [cb2],
(req, res, next) => {
console.log('--cb3--');
next();
},
(req, res, next) => {
res.send('hello');
});
middleware之间传值
使用 res.locals.key=value;
app.use(function(req, res, next) {
res.locals.user = req.user;
res.locals.authenticated = ! req.user.anonymous;
next();
});
传给下一个
app.use(function(req, res, next) {
if (res.locals.authenticated) {
console.log(res.locals.user.id);
}
next();
});
表单提交及json格式提交
var express = require('express');
var app = express();
var bodyParser = require('body-parser');
// 支持解析json格式
app.use(bodyParser.json());
// 支持解析 application/x-www-form-urlencoded 编码，就是表单提交
var urlencodedParser = bodyParser.urlencoded({ extended: false })
// 这个urlencodedParser必须带，不然 request.body 为 undefined
app.post('/', urlencodedParser, function(request, response) {
console.dir(request.body);
response.send('It works');
}
});
-
不带 app.use(bodyParser.json()); 不支持下面的提交
image.png
也就是
Content-Type: application/json -
带 var urlencodedParser = bodyParser.urlencoded({ extended: false })
image.png
参考：
http://expressjs.com/en/resources/middleware/body-parser.html
