react-examples/professional_javascript_for_web/ch21/XHRAlternateEventsExample01.htm at master · zhangjunhd/react-examples · GitHub

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<!DOCTYPE html>
<html>
<head>
    <title>XHR Alternate Events Example</title>
</head>
<body>
    <p>This example must be run on a server to work properly and will only work in Firefox.</p>
    <div id="status"></div>
    <script type="text/javascript">

        function createXHR(){
            if (typeof XMLHttpRequest != "undefined"){
                return new XMLHttpRequest();
            } else if (typeof ActiveXObject != "undefined"){
                if (typeof arguments.callee.activeXString != "string"){
                    var versions = ["MSXML2.XMLHttp.6.0", "MSXML2.XMLHttp.3.0",
                                    "MSXML2.XMLHttp"];

                    for (var i=0,len=versions.length; i < len; i++){
                        try {
                            var xhr = new ActiveXObject(versions[i]);
                            arguments.callee.activeXString = versions[i];
                            return xhr;
                        } catch (ex){
                            //skip
                        }
                    }
                }

                return new ActiveXObject(arguments.callee.activeXString);
            } else {
                throw new Error("No XHR object available.");
            }
        }

        var xhr = createXHR();
        xhr.onload = function(event){
            alert(xhr.responseText);
            alert(xhr.status);
        };
        xhr.onerror = function(event){
            alert("Error: " + xhr.status);
        };
        xhr.onprogress = function(event){
            var statusDiv = document.getElementById("status");
            statusDiv.innerHTML = "Received " + event.position + " of " + event.totalSize;
        };
        xhr.onloadend = function(event){
            alert("End!");
        };
        xhr.open("get", "example.txt", true);

        xhr.send(null);

    </script>
</body>
</html>