发送Json对象时XMLHttpRequest返回状态0

Question

I'm trying to get a response from the server but i'm getting a null status. Where i'm getting wrong? I would like to send from an Script to a server within Max4live Patch.

 var xhr = new XMLHttpRequest();
 var url = 'myURL'


log("1");
xhr.open('PUT', url, true, 'myUser', 'myPass');
log("2");
xhr.setRequestHeader('Content-Type', 'application/json');

log("4");

xhr.send(JSON.stringify(JsonExport));
log("5");
log("Status: "+xhr.status+ " "+xhr.statusText);

    if (xhr.status == 4) {
        var userInfo = JSON.parse(xhr.responseText);
        log("Status");
        log(xhr.responseText);
        log(userInfo);
    } else {
        log("Response");
        log(xhr.responseText);
    }

//log(xhr.responseType["json"]);
delete xhr;

i'm getting on the line : log("Status: "+xhr.status+ " "+xhr.statusText) : Status:0 null ... where I would like to get a json object from the server. Any idea? Thanks!

Answer 1

You make an asynchronous request (see third parameter of xhr.open() ), and your request is not finished when checking the status.

For async requests you need to implement an onreadystagechange handler.

For example take a look at http://www.w3schools.com/ajax/ajax_xmlhttprequest_onreadystatechange.asp