Ajax File Upload Not Working for IE8

Question

I'm having trouble uploading a file using a Javascript function that makes an Ajax call to a servlet. The file is uploaded perfectly when I use chrome, but not when I use IE8 (Go figure).

I used to have a file select button on the bottom of my form. When I clicked that button a function would be called and it would upload the file to the servlet using ajax. This worked perfectly in IE8, but the client wanted links instead. So now I have the links in the form, and the buttons hidden with css. The links call the click event of the buttons. Now the file uploading only works with Chrome, and not IE8.

The request never makes it to the servlet for some reason, and for some reason the ajax request returns success. Any idea what the problem might be?

Here is my code:

//Uploading a file
    $("#uploaded_file").change(function() {
        var filename = $(this).val();
        if(isAcceptable(filename)) {
            $.ajaxFileUpload
            (
                {
                    type: "POST",
                    url:'GenerateServlet', 
                    secureuri:false,
                    fileElementId:'uploaded_file',
                    dataType: 'json',
                    success: function (data, status)
                    {
                        if(typeof(data.error) != 'undefined')
                        {
                            if(data.error != '')
                            {
                                alert(data.error);
                            }else
                            {
                                alert(data.msg);
                            }
                        }
                        fillTemplate(data);

                    }
                }
            )
        }
        else if(filename.length > 0){
            $("#uploaded_file").val("");
            alert("Invalid File! Please select another file")
        }
    });

$("#upload_link").click(function() {
        document.getElementById('uploaded_file').click();
        return false;
    });

Here is the upload function:

jQuery.extend({


    createUploadIframe: function(id, uri)
    {
            //create frame
            var frameId = 'jUploadFrame' + id;
            var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" style="position:absolute; top:-9999px; left:-9999px"';
            if(window.ActiveXObject)
            {
                if(typeof uri== 'boolean'){
                    iframeHtml += ' src="' + 'javascript:false' + '"';

                }
                else if(typeof uri== 'string'){
                    iframeHtml += ' src="' + uri + '"';

                }   
            }
            iframeHtml += ' />';
            jQuery(iframeHtml).appendTo(document.body);

            return jQuery('#' + frameId).get(0);            
    },
    createUploadForm: function(id, fileElementId, data)
    {
        //create form   
        var formId = 'jUploadForm' + id;
        var fileId = 'jUploadFile' + id;
        var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');    
        if(data)
        {
            for(var i in data)
            {
                jQuery('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);
            }           
        }       
        var oldElement = jQuery('#' + fileElementId);
        var newElement = jQuery(oldElement).clone();
        jQuery(oldElement).attr('id', fileId);
        jQuery(oldElement).before(newElement);
        jQuery(oldElement).appendTo(form);



        //set attributes
        jQuery(form).css('position', 'absolute');
        jQuery(form).css('top', '-1200px');
        jQuery(form).css('left', '-1200px');
        jQuery(form).appendTo('body');      
        return form;
    },

    ajaxFileUpload: function(s) {
        // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout        
        s = jQuery.extend({}, jQuery.ajaxSettings, s);
        var id = new Date().getTime()        
        var form = jQuery.createUploadForm(id, s.fileElementId, (typeof(s.data)=='undefined'?false:s.data));
        Console.log(form);
        var io = jQuery.createUploadIframe(id, s.secureuri);
        var frameId = 'jUploadFrame' + id;
        var formId = 'jUploadForm' + id;        
        // Watch for a new set of requests
        if ( s.global && ! jQuery.active++ )
        {
            jQuery.event.trigger( "ajaxStart" );
        }            
        var requestDone = false;
        // Create the request object
        var xml = {}   
        if ( s.global )
            jQuery.event.trigger("ajaxSend", [xml, s]);
        // Wait for a response to come back
        var uploadCallback = function(isTimeout)
        {           
            var io = document.getElementById(frameId);
            try 
            {               
                if(io.contentWindow)
                {
                     xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
                     xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;

                }else if(io.contentDocument)
                {
                     xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
                    xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
                }                       
            }catch(e)
            {
                jQuery.handleError(s, xml, null, e);
            }
            if ( xml || isTimeout == "timeout") 
            {               
                requestDone = true;
                var status;
                try {
                    status = isTimeout != "timeout" ? "success" : "error";
                    // Make sure that the request was successful or notmodified
                    if ( status != "error" )
                    {
                        // process the data (runs the xml through httpData regardless of callback)
                        var data = jQuery.uploadHttpData( xml, s.dataType );    
                        // If a local callback was specified, fire it and pass it the data
                        if ( s.success )
                            s.success( data, status );

                        // Fire the global callback
                        if( s.global )
                            jQuery.event.trigger( "ajaxSuccess", [xml, s] );
                    } else
                        jQuery.handleError(s, xml, status);
                } catch(e) 
                {
                    status = "error";
                    jQuery.handleError(s, xml, status, e);
                }

                // The request was completed
                if( s.global )
                    jQuery.event.trigger( "ajaxComplete", [xml, s] );

                // Handle the global AJAX counter
                if ( s.global && ! --jQuery.active )
                    jQuery.event.trigger( "ajaxStop" );

                // Process result
                if ( s.complete )
                    s.complete(xml, status);

                jQuery(io).unbind()

                setTimeout(function()
                                    {   try 
                                        {
                                            jQuery(io).remove();
                                            jQuery(form).remove();  

                                        } catch(e) 
                                        {
                                            jQuery.handleError(s, xml, null, e);
                                        }                                   

                                    }, 100)

                xml = null

            }
        }
        // Timeout checker
        if ( s.timeout > 0 ) 
        {
            setTimeout(function(){
                // Check to see if the request is still happening
                if( !requestDone ) uploadCallback( "timeout" );
            }, s.timeout);
        }
        try 
        {

            var form = jQuery('#' + formId);
            jQuery(form).attr('action', s.url);
            jQuery(form).attr('method', 'POST');
            jQuery(form).attr('target', frameId);
            if(form.encoding)
            {
                jQuery(form).attr('encoding', 'multipart/form-data');               
            }
            else
            {   
                jQuery(form).attr('enctype', 'multipart/form-data');            
            }           
            jQuery(form).submit();

        } catch(e) 
        {           
            jQuery.handleError(s, xml, null, e);
        }

        jQuery('#' + frameId).load(uploadCallback   );
        return {abort: function () {}}; 

    },

    uploadHttpData: function( r, type ) {
        var data = !type;
        data = type == "xml" || data ? r.responseXML : r.responseText;
        // If the type is "script", eval it in global context
        if ( type == "script" )
            jQuery.globalEval( data );
        // Get the JavaScript object, if JSON is used.
        if ( type == "json" )
            eval( "data = " + data );
        // evaluate scripts within html
        if ( type == "html" )
            jQuery("<div>").html(data).evalScripts();

        return data;
    }
})

Answer 1

That is a typical Microsoft security measure (eg to stop automated uploads).

That means you have to originate an upload from an actual user-pressed button click.

Style the button to make it look like a link instead.