允许远程服务器通过参数接受来自本地主机的请求

Question

I have my application running locally on my computer and it is trying to connect to my remote nodeJS/Express server. I have set the headers in my remote server.

Main question: How do I allow my remote server to accept requests coming from my localhost with parameters? People have told me that my request will not work because the requested URL and the server URL do not share the same domain. The request is coming from my localhost and it is trying to access my remote node/express server. This transaction works when I remove the params in the request but does NOT work when I have the params.

This is how I set headers in my remote server to accept all requests:

app.use(function (req, res, next) {
  res.setHeader("Access-Control-Allow-Origin", "http://localhost:9000");
  res.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");

  if(res.headersSent) {
    console.log("Headers sent");
  }
  else {
    console.log("Headers not sent");
  }
  next();
});

Also, the res.headersSent keeps evaluating to false even though I can see the headers set in my Google network tab. Why is this value returning false?

This is how I am making my GET request to my server from my localhost:

var req = $http({
        url: 'https://20161128t135355-dot-jarvis-hd-live-2.appspot-preview.com/read-message',
        method: 'GET',
        cache: false,
        params: {last_updated: last_updated_time}
    });

This post was not helpful How to enable cross-origin resource sharing (CORS) in the express.js framework on node.js

I think the params is causing the error, because it works fine when I take it out. I get this error:

XMLHttpRequest cannot load https://20161128t135355-dot-jarvis-hd-live-2.appspot-preview.com/read-message?last_updated=0. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:9000' is therefore not allowed access. The response had HTTP status code 502.

All the solutions say to add/set the header and as you can see I have done that but my application still gives me the same error when I include params in the request. What should I do differently?

Answer 1

So that means your problem is that your server side code throws an error when you add params to the request. You need to debug that. The CORS stuff is almost certainly irrelevant.

This issue is not a CORS issue, it has something to do with my params request. To fix this, I had to configure body-parser like so:

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

This helps when sending JSON data to the client from the server or vice versa. You can find more information here: http://junerockwell.com/difference-parameters-query-strings-express-js/