使用node.js和express处理POST请求

Question

I am new to learning AJAX and new to web development at all, and I am having trouble having my local server and my remote server process a post request. I am using node.js and the express module.

Here is the code of my server:

var express = require('express');

//start server
var app = express.createServer();

//handle requests
app.post('/hello', function(req, res){
    res.send("hello");
});

app.listen(8888);

Pretty basic, I know. To test this, I create an XMLHttpRequest manually through the console in Chrome (I have disabled the Cross-Origin policy to test on my local machine):

var xhr = new XMLHttpRequest();
xhr.open('POST', 'localhost:8888/hello', true);
xhr.send('name=me'); //body of request is irrelevant at this point

When I send the request to my local machine, it returns immediately and says it failed. When I send the request to my remote server (where localhost is replaced by my server's IP) I don't get the error in my console, but when I check the xhr object's status is failed.

I don't know whether the problem is with the way my server is written, or the way I am sending the request to the server. However, I have been looking at tutorials and examples that show express processing post requests like I do above, and other tutorials that show sending POST requests like I do above.

Sending and processing GET requests seems to work fine. I must be missing something.

Thanks, Xaan.

Answer 1

发出POST时，您需要在URL中包括HTTP：

xhr.open('POST', 'http://localhost:8888/hello', true);

Answer 2

XHR does not work if the calling js is not served by a webserver.

What you should do is add a simple route on your Express server

app.get('/', function( req, res) {
  res.sendfile('index.html');
})

Where index.html contains your testing code.

If you want to test from a different webserver and be confronted with the annoying Cross-Origin policy you can also use this super usefull command to spawn a webserver in your current folder:

python -m SimpleHTTPServer

I use it so often that I actually alias it:

alias www='python -m SimpleHTTPServer'