Https POST / GET with Qml/Qt

问题:

Recently I'm working on Nokia mobiles using Qt-Qml. I have to make a POST request to a given HTTPS Url. I'm using QML and I'm trying to do it in Javascript without any luck.

Anyone has an idea about it? It's possible to do it using Javascript in QML? Any advise on how to make it in QT?

I tried calling a function like this:

var http = new XMLHttpRequest()
var url = "myform.xsl_submit";
var params = "num=22&num2=333";
http.open("POST", url, true);

//Send the proper header information along with the request
http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
http.setRequestHeader("Content-length", params.length);
http.setRequestHeader("Connection", "close");

http.onreadystatechange = function() {//Call a function when the state changes.
    if(http.readyState == 4 && http.status == 200) {
        print("ok");
    }else{
                print("cannot connect");
        }
}
http.send(params);

回答1:

Your if statement is wrong: The function is called several times, but only one time http.readyState = 4. So, you print error messages although there's no errors yet.

You should first check if http.readyState = 4, and then look at the status code.

Here is a minimal working example:

import QtQuick 1.1

Rectangle {
    Component.onCompleted: {
        var http = new XMLHttpRequest()
        var url = "http://localhost:8080";
        var params = "num=22&num2=333";
        http.open("POST", url, true);

        // Send the proper header information along with the request
        http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
        http.setRequestHeader("Content-length", params.length);
        http.setRequestHeader("Connection", "close");

        http.onreadystatechange = function() { // Call a function when the state changes.
                    if (http.readyState == 4) {
                        if (http.status == 200) {
                            console.log("ok")
                        } else {
                            console.log("error: " + http.status)
                        }
                    }
                }
        http.send(params);
    }
}

I created a local pseudo-webserver with netcat to test it:

% echo -e 'HTTP/1.1 200 OK\n\n' | nc -l 8080 
POST / HTTP/1.1
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
Content-Length: 15
Connection: Keep-Alive
Accept-Encoding: gzip
Accept-Language: de-DE,en,*
User-Agent: Mozilla/5.0
Host: localhost:8080

num=22&num2=333