我最近学习了一个关于如何构建Express服务器的简单教程(https://codeforgeek.com/2014/06/express-nodejs-tutorial/)。
我正试图从本教程扩展代码,以便我可以响应post请求。我想通过更新一个json文件来做到这一点(它恰好充满了'用户评论',然后在'/'
重新渲染。/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');
});
。/路由器/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')
});
}
。/视图/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"}
]
}
当我尝试从我的表单提交一个新的评论时,我所看到的是:
"Cannot POST/"
谁能解释一下为什么我可能会得到这个错误?由于
实际上有几个问题,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
的模块。我目前只熟悉bodyParser
,你可能应该研究一下。虽然它显示在Express 4中。当您运行该服务器时,您会得到一条弃用消息。
另一个问题是comments.push
的问题。应该是comments.comments.push
。以下作品:
router.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');
})