Question

My Javascript code that is run in client-side needs to read a binary file that is stored in the server. How can I do it for all browsers?

I have found solutions with ActiveXObject – FileSystemObject that are only working in Internet Explorer.

Thanks

Answer 1

function getXHR(){
    var xhr;
    try{
        xhr = new XMLHttpRequest();
    }catch(e){
        try{
            xhr = new ActiveXObject("MSXML2.XMLHTTP.6.0");
        }catch(e2){
            try{
                xhr = new ActiveXObject("MSXML2.XMLHTTP");
            }catch(e3){}
        }
    }
    return xhr;
}


function getBinaryData(url, callback){
    var xhr = getXHR();
    xhr.open("GET", url, !!callback);
    if(callback){
        xhr.onload = function(){callback(xhr, true)};
        xhr.onerror = function(){callback(xhr, false)};
    }
    xhr.send();
    return callback ? undefined : xhr.responseText;
}

You would then use getBinaryData to get the file. with asynchronous, it will call the callback with arguments the xhr object itself (you would read the responseText property), and whether it was successful. Synchronously, it returns the binary data.