ExpressJS：如何从全局中间件转储 req.params

Question

我无法为 ExpressJS 编写一个非常简单的中间件来记录所有 req.params 到控制台。似乎如果我将中间件添加到特定函数，它就可以工作，而早期 app.use () 中的相同代码不会在 req.params.

中获取任何数据

这是一个示例代码：

const express = require('express')

const app = express();

// Simply log the req.params to console
const middle = ( req, res, next ) =>
{
    console.log ( "PARAMS: ", req.params );

    next ();
};

// Trying to access req.params in a global middleware does not work
app.use ( middle );

app.get('/', function (req, res) {
  res.send('hello, world!')
})

// Specifying middleware in mount point works
app.get ( "/hello/:world", middle, ( req, res ) =>
{
    console.log ( "This works: ", req.params );
    res.send ( 'hello' );
} );

app.listen(3000, function () {
  console.log('Example app listening on port 3000!');
});

Answer 1

它不能作为全局中间件工作，因为这个参数只存在于 url "/hello/:world" 中，并且 express 在运行这个特定的 url 中间件之前不会知道这个参数。

可以用process.nextTick来解决

const middle = ( req, res, next ) => {
    process.nextTick(() => console.log ( "PARAMS: ", req.params ));

    next ();
};

ExpressJS：如何从全局中间件转储 req.params

ExpressJS: how to dump req.params from a global middleware

javascript

middleware

node.js