AJAX responseXML errors

Question

I\'ve been having some weird issues when it comes to make an AJAX request and handling the response.

I am making an ajax call for an xml file. however when i get the

Answer 1

I was having the same problem a few years ago, then I gave up on responseXML and began always using responseText. This parsing function has always worked for me:

function parseXml(xmlText){
    try{
        var text = xmlText;
        //text = replaceAll(text,"&lt;","<");
        //text = replaceAll(text,"&gt;",">");
        //text = replaceAll(text,"&quot;","\"");
        //alert(text);
        //var myWin = window.open('','win','resize=yes,scrollbars=yes');
        //myWin.document.getElementsByTagName('body')[0].innerHTML = text;
        if (typeof DOMParser != "undefined") { 
            // Mozilla, Firefox, and related browsers 
            var parser=new DOMParser();
            var doc=parser.parseFromString(text,"text/xml");
            //alert(text);
            return doc; 
        }else if (typeof ActiveXObject != "undefined") { 
            // Internet Explorer. 
        var doc = new ActiveXObject("Microsoft.XMLDOM");  // Create an empty document 
            doc.loadXML(text);            // Parse text into it 
            return doc;                   // Return it 
        }else{ 
            // As a last resort, try loading the document from a data: URL 
            // This is supposed to work in Safari. Thanks to Manos Batsis and 
            // his Sarissa library (sarissa.sourceforge.net) for this technique. 
            var url = "data:text/xml;charset=utf-8," + encodeURIComponent(text); 
            var request = new XMLHttpRequest(); 
            request.open("GET", url, false); 
            request.send(null); 
            return request.responseXML; 
        }
    }catch(err){
        alert("There was a problem parsing the xml:\n" + err.message);
    }
}

With this XMLHttpRequest Object:

// The XMLHttpRequest class object

debug = false;

function Request (url,oFunction,type) {
    this.funct = "";
    // this.req = "";
    this.url = url;
    this.oFunction = oFunction;
    this.type = type;
    this.doXmlhttp = doXmlhttp;
    this.loadXMLDoc = loadXMLDoc;
}

function doXmlhttp() {
    //var funct = "";
    if (this.type == 'text') {
        this.funct = this.oFunction + '(req.responseText)';
    } else {
        this.funct = this.oFunction + '(req.responseXML)';
    }
    this.loadXMLDoc();
    return false;
}

function loadXMLDoc() {
    //alert(url);
    var functionA = this.funct;
    var req;
    req = false;

    function processReqChange() {
        // alert('reqChange is being called');
        // only if req shows "loaded"
        if (req.readyState == 4) {
            // only if "OK"
            if (req.status == 200) {
                // ...processing statements go here...
                eval(functionA);
                if(debug){
                    var debugWin = window.open('','aWindow','width=600,height=600,scrollbars=yes');
                    debugWin.document.body.innerHTML = req.responseText;
                }
            } else {
                alert("There was a problem retrieving the data:\n" +
                    req.statusText + '\nstatus: ' + req.status);
                if(debug){
                    var debugWin = window.open('','aWindow','width=600,height=600,scrollbars=yes');
                    debugWin.document.body.innerHTML = req.responseText;
                }
            }
            }
    }

    // branch for native XMLHttpRequest object
    if(window.XMLHttpRequest) {
        try {
            req = new XMLHttpRequest();
        } catch(e) {
            req = false;
        }
    // branch for IE/Windows ActiveX version
    } else if(window.ActiveXObject) {
        try {
                req = new ActiveXObject("Msxml2.XMLHTTP");
        } catch(e) {
                try {
                    req = new ActiveXObject("Microsoft.XMLHTTP");
                } catch(e) {
                    req = false;
                }
        }
    }



    if(req) {
        req.onreadystatechange = processReqChange;
        if(this.url.length > 2000){
            var urlSpl = this.url.split('?');
            req.open("POST",urlSpl[0],true);
            req.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
            req.send(urlSpl[1]);
        } else {
            req.open("GET", this.url, true);
            req.send("");
        }
    }
}

function browserSniffer(){
    if(navigator.userAgent.toLowerCase().indexOf("msie") != -1){
        if(navigator.userAgent.toLowerCase().indexOf("6")){
            return 8;
        }else{
            return 1;
        }
    }
    if(navigator.userAgent.toLowerCase().indexOf("firefox") != -1){
        return 2;
    }
    if(navigator.userAgent.toLowerCase().indexOf("opera") != -1){
        return 3;
    }
    if(navigator.userAgent.toLowerCase().indexOf("safari") != -1){
        return 4;
    }
    return 5;
}

Granted, this is very old code, but it is still working for me on a site I built a few years ago. I agree with everyone else though I typically use a framework nowadays so I don't have to use this code or anything like it anymore.

You can ignore some of the particulars with the split, etc... in the Request onreadystate function. It was supposed to convert the request to a post if it was longer than a certain length, but I just decided it was always better to do a post.

Answer 2

The answer provided by Aron in https://stackoverflow.com/a/2081466/657416 is from my point of view the simplest (and the best) one. Here is my working code:

ajax = ajaxRequest();
ajax.overrideMimeType("text/xml");
ajax.open("GET", myurl;

Answer 3

To avoid your cross browser problems (and save yourself coding a lot of items that a strong community has already developed, tested, and reviewed), you should select a javascript library. JQuery and Dojo are great choices.

Answer 4

I believe that your web server need to serve correct response headers with 'ConferenceRoomSchedules.xml' e.g. Content-Type: text/xml or any other xml type.

Answer 5

This problem occurs mostly when content type is mis-detected by the browser or it's not sent correctly.

Its easier to just override it:

var request = new XMLHttpRequest(); 
request.open("GET", url, false); 
request.overrideMimeType("text/xml");
request.send(null); 
return request.responseXML; 

Not sure why... This problem occurs only with Safari and Chrome (WebKit browsers, the server sends the headers correctly).

Answer 6

What I can suggest you is to take a look at frameworks that hide and manage these cross-browser issues for you (in a reliable way). A good point here is jQuery. Doing these things yourself can become quite difficult and complex.

This may be what you need.

//Edit: This is how the w3school shows it:

function ajaxFunction()
{
var xmlhttp;
if (window.XMLHttpRequest)
  {
  // code for IE7+, Firefox, Chrome, Opera, Safari
  xmlhttp=new XMLHttpRequest();
  }
else if (window.ActiveXObject)
  {
  // code for IE6, IE5
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }
else
  {
  alert("Your browser does not support XMLHTTP!");
  }
}