XMLHttpRequest（）。send（）在Chrome和Opera中不起作用

Question

The following javascript function works fine for IE, Safari and Firefox. But it fails in Chrome(33.0.) and Opera (16.0.1196). Blank HTML page is displayed on loading.

function readTestXMLFile() {

    if (window.ActiveXObject) { 
        var xmlDoc = new ActiveXObject('Microsoft.XMLDOM');
        xmlDoc.async = 'false';
        xmlDoc.load('test.xml');
    }
    else {     
        var requ = new XMLHttpRequest();
        alert("a");

        requ.open("GET", "test.xml", false);
        alert("b");

        requ.send(null);    //This line is not working in chrome and opera
        alert("c");

        var xmlDoc = requ.responseXML;
        alert(xmlDoc);
        alert("d");
    }

    return xmlDoc;
}

Only 'a' and 'b' gets printed. It does not continue after that. Same result is observed if I use requ.send() or requ.send("") instead of requ.send(null).

If I remove the statement requ.send(null), then 'null' value is printed for xmlDoc. Still blank HTML loads.

Please let me know what is the right way to get this work on Chrome and Opera.

Thanks

SRB.

Answer 1

Your error message suggest that you are trying to access a local file which is treated as "Cross origin request" if you try and run local server it should work.

Take a look at this previously asked question with the same problem: Cross origin requests are only supported for HTTP but it's not cross-domain

Then you would access http://localhost/.../test.xml instead of c:/localhost/.../test.xml

You can also set a flag for Chrome to allow local files to request local files: -allow-file-access-from-files

Answer 2

the call to the XMLHttpRequest.send method is Asynchronous so you need to modify the call a little bit. The modified code below will print the response content when the response is returned successfully:

 requ.addEventListener("load", function(e) {
           alert(req.responseText);
        }, false)

 requ.send(null);

Update: I didn't notice that you made the send request call synchronous.

Edit You need to launch chrome with this parameter to be able to access local files

--allow-file-access-from-files

ex: c:\\Browser\\chrome.exe --allow-file-access-from-files

Answer 3

I think that the problem is that you're passing null to the send() method. You are making a GET request, so you should call send without parameters. I think chrome throws an exception because of that. Just remove the null