Express Server - 无法POST /

Question

我最近关于如何构建Express服务器的简单教程(https://codeforgeek.com/2014/06/express-nodejs-tutorial/).

我正在尝试扩展本教程中的代码,以便我可以响应发布请求.我想通过更新一个json文件(恰好填充'用户注释',然后在'/'处重新渲染)来做到这一点

./server.js:

var express = require('express');
var app = express();

// routing configuration
require('./router/main')(app);

// ejs configuration
app.set('views', __dirname + '/views');
app.set('view engine', 'ejs');
app.engine('html', require('ejs').renderFile);

// run the server
var server = app.listen(8080, function(){
  console.log('Express server listening on port 8080');
});

./router/main.js(路由器):

var fs = require('fs');
var ejs = require('ejs')

module.exports = function(app){

  app.get('/', function(req, res){
    var comments = JSON.parse(fs.readFileSync(__dirname + '/../comments.json'));
    res.render('index.ejs', comments);
  });

  app.post('/', function(req, res){
    console.log('here in post');
    var name = req.body.name;
    var message = req.body.message;
    var newComment = {"name": name, "message": message};
    var comments = JSON.parse(fs.readFileSync(__dirname + '/../comments.json'));
    comments.push(newComment);
    fs.writeFileSync(__dirname + '/../comments.json', comments, 'utf8');
    //redirect to a 'get' on '/'
    res.redirect('/');
  });

  app.get('/about', function(req, res){
    res.render('about.html')
  });

}

./views/index.ejs:

<div>

  <div>
    <h1> Joe's Forum </h1>
    <a href='/about'> (about) </a>
  </div>

  <div>
    <ul>
    <% comments.forEach( function(comment){ %>
      <li>
        <%= comment.name %> : <%= comment.message %>
      </li>
    <% }); %>
    </ul>
  </div>

  <h2> Enter a new comment </h2>

  <form action='/' method="post">
    Enter your name: <input type='text' name='name'> <br><br>
    Enter your message: <input type='textarea' name='message'> <br><br>
    <input type='submit' value='Submit'>
  <form>

</div>

./comments.json:

{
  "comments": [
    {"name":"Joe", "message" : "What advantages does Node.js afford the web developer?"},
    {"name": "John", "message": "Asynchronous IO helps us to keep our pages responsive even if the server is fetching data"}
  ]
}

当我尝试从表单中提交新评论时,我看到的是:

"不能POST /"

有人可以解释为什么我可能会收到此错误吗？谢谢

Answer 1

实际上存在一些问题，但主要问题是您没有正文解析器 - 将 POST 中的节点流转换为req.body. 我目前只熟悉bodyParser，你可能应该研究一下。尽管它显示在 Express 4.x 文档中，但在运行服务器时会收到一条弃用消息。

另一个问题是comments.push. 那应该是comments.comments.push。以下工作：

路由器.js：

var fs = require('fs');
var ejs = require('ejs')

module.exports = function(app){

  app.get('/', function(req, res){
    var comments = JSON.parse(fs.readFileSync(__dirname + '/../comments.json'));
    res.render('index.ejs', comments);
  });

  app.post('/', function(req, res){
    console.log('here in post');
    console.log(req.body)
    var name = req.body.name;
    var message = req.body.message;
    var newComment = {"name": name, "message": message};
    var comments = JSON.parse(fs.readFileSync(__dirname + '/../comments.json'));
    comments.comments.push(newComment);
    fs.writeFileSync(__dirname + '/../comments.json', JSON.stringify(comments), 'utf8');
    //redirect to a 'get' on '/'
    res.redirect('/');
  });

  app.get('/about', function(req, res){
    res.render('about.html')
  });

}

和 server.js：

var express = require('express');
var bodyParser = require('body-parser');
var app = express();

app.use(bodyParser.urlencoded())

// routing configuration
require('./router/main')(app);

// ejs configuration
app.set('views', __dirname + '/views');
app.set('view engine', 'ejs');
app.engine('html', require('ejs').renderFile);

// run the server
var server = app.listen(8080, function(){
  console.log('Express server listening on port 8080');
})