Angular http.post作为Options方法的请求

Question

I'm trying to post some data to node server, but I have an issue:

postEmployeeForm(employee: Employee):Observable<any> {
        let body = JSON.stringify(employee);
        let headers = new Headers({ 'Content-Type': 'application/json' });
        let options = new RequestOptions({ headers: headers });

        return this.http.post('http://localhost:3100/postemployee', body, options)
             .map(this.extractData)
             .catch(this.handleError);
    }

This is my post request by in Network tab I see this as Options method while on server I'm expecting a post request.

If I omit options from http.post then I get post request on server, but then I have error about unexpected content type.

postEmployeeForm(employee: Employee):Observable<any> {
        let body = JSON.stringify(employee);

        return this.http.post('http://localhost:3100/postemployee', body)
             .map(this.extractData)
             .catch(this.handleError);
    }

Is this expected behaviour or I'm doing something wrong with post. I found this code on official angular guide: server-communication How to handle this situation, do I need to change something on client side or should I handle that on server side?

EDIT:

This is my server code:

var http = require('http');
var formidable = require("formidable");
var util = require('util');

var server = http.createServer(function(req, res) {
    res.setHeader('Access-Control-Allow-Origin','*');
    res.setHeader('Access-Control-Allow-Headers','Origin, X-Requested-With, Content-Type, Accept');

    if(req.method.toLowerCase() == 'post') {
        console.log("Get request!");
        processForm(req,res);
        return;
    }
});

function processForm(req,res) {

    var form = new formidable.IncomingForm();
    form.parse(req, function(err, fields) {

        res.writeHead(200, {
            'content-type': 'application/json'
        });

        res.end(util.inspect({
            fields: fields
        }));

        console.log('posted fields:\n');
        console.log(util.inspect({
            fields: fields
        }));
    });
}

var port = 3100;
server.listen(port,'localhost');
console.log("server listening on port " + port);

Answer 1

The problem is on server side. You need to implement hanlder for options. example:

app.options("*",function(req,res,next){
  res.header("Access-Control-Allow-Origin", req.get("Origin")||"*");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
   //other headers here
    res.status(200).end();
});

http://expressjs.com/en/api.html#app.METHOD