Function fileUploadIframe

static/js/jquery.form.js:344–827

(a)

        // private function for handling file uploads (hat tip to YAHOO!)
        function fileUploadIframe(a) {
            var form = $form[0], el, i, s, g, id, $io, io, xhr, sub, n, timedOut, timeoutHandle;
            var deferred = $.Deferred();

            // #341
            deferred.abort = function(status) {
                xhr.abort(status);
            };

            if (a) {
                // ensure that every serialized input is still enabled
                for (i=0; i < elements.length; i++) {
                    el = $(elements[i]);
                    if ( hasProp ) {
                        el.prop('disabled', false);
                    }
                    else {
                        el.removeAttr('disabled');
                    }
                }
            }

            s = $.extend(true, {}, $.ajaxSettings, options);
            s.context = s.context || s;
            id = 'jqFormIO' + (new Date().getTime());
            if (s.iframeTarget) {
                $io = $(s.iframeTarget);
                n = $io.attr2('name');
                if (!n) {
                    $io.attr2('name', id);
                }
                else {
                    id = n;
                }
            }
            else {
                $io = $('<iframe name="' + id + '" src="'+ s.iframeSrc +'" />');
                $io.css({ position: 'absolute', top: '-1000px', left: '-1000px' });
            }
            io = $io[0];


            xhr = { // mock object
                aborted: 0,
                responseText: null,
                responseXML: null,
                status: 0,
                statusText: 'n/a',
                getAllResponseHeaders: function() {},
                getResponseHeader: function() {},
                setRequestHeader: function() {},
                abort: function(status) {
                    var e = (status === 'timeout' ? 'timeout' : 'aborted');
                    log('aborting upload... ' + e);
                    this.aborted = 1;

                    try { // #214, #257
                        if (io.contentWindow.document.execCommand) {