How to receive notification on 404,409 and other server errors on jsonp call

Question

I have this jsonp function:

    function jsonp(url, callback) {
    var script = document.createElement("script");
    script.setAttribute("type","text/javascript");
    script.setAttribute("onerror","javascript:DisplayPopUp('','staleExceptionRefresh')");
    script.setAttribute("src", url + questionMark + "accept=jsonp&callback="+callback + "&cachebuster="+new Date().getTime());
    document.getElementsByTagName("head")[0].appendChild(script);
}

I catch the success event like this:

function someCallbackFunction(data1, data2) {}

but the problem is that if I get 404 or 409 or some other server errors I don't know how to catch them (they do not appear on someCallbackFunction).

I can set an onerror attribute to display something but how do I catch the server's response.

this is an example for a server response that I am not able to catch with my regular callback function:

DeleteWebsiteAjaxCall({"action":"", "type":"", "callerId":""}, {errorDescription: "important description I want to display","success":false,"payload":null});

How do I catch these errors (stale exceptions?!) on a function?

xiaoyi · Accepted Answer · 2012-11-14T12:34:08.720

function jsonp(url, callback) {
    var script = document.createElement("script");
    script.setAttribute("type","text/javascript");
    script.setAttribute("src", url + questionMark + "accept=jsonp&callback="+callback + "&cachebuster="+new Date().getTime());
    var errHandler = function(evt) {
      clearTimeout(timer)
      // reference to http://www.quirksmode.org/dom/events/error.html
      // you will get an error eventually, and you can call callback manually here, to acknowledge it.
      // but unfortunately, on firefox you can get error type as undefined, and no further detail like error code on other browser either. 
      // And you can tell the callback function there is a net error (as no other error will fire this event.)
      window[callback](new Error());
    };
    script.onerror = errHandler;
    script.onload = function() {
      clearTimeout(timer);
    }
    // also setup a timeout in case the onerror failed.
    document.getElementsByTagName("head")[0].appendChild(script);
    var timer = setTimeout(errHandler, 5000);
}

If your server will response when 404/409 happens, then send the 200 status code to client instead to make the script being evaluated.

Otherwise, the browser will omit the server response and fire onerror event.

How to receive notification on 404,409 and other server errors on jsonp call

1 Answers1