ajaxFileUpload.js

// JavaScript Document
jQuery.extend({

    createUploadIframe: function(id, uri) {
        //create frame
        var frameId = 'jUploadFrame' + id;

        if (window.ActiveXObject) {
            var io = document.createElement('<iframe id="' + frameId + '" name="' + frameId + '" />');
            if (typeof uri == 'boolean') {
                io.src = 'javascript:false';
            } else if (typeof uri == 'string') {
                io.src = uri;
            }
        } else {
            var io = document.createElement('iframe');
            io.id = frameId;
            io.name = frameId;
        }
        io.style.position = 'absolute';
        io.style.top = '-1000px';
        io.style.left = '-1000px';

        document.body.appendChild(io);

        return io;
    },
    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>');
        /********************原版 bug 已解决 **********************/
        /*for (var i in fileElementId) {   //原版
            var oldElement = jQuery('#' + fileElementId);
            var newElement = jQuery(oldElement).clone();
            jQuery(oldElement).attr('id', fileId);
            jQuery(oldElement).before(newElement);
            jQuery(oldElement).appendTo(form);
        }*/
        //修改版
        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');
        if (data) {
            for (var i in data) {
                $('<input type="hidden" name="' + i + '" value="' + data[i] + '" />').appendTo(form);
            }
        }
        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 = s.fileElementId;
        var form = jQuery.createUploadForm(id, s.fileElementId, s.data);
        var io = jQuery.createUploadIframe(id, s.secureuri);
        var frameId = 'jUploadFrame' + id;
        var formId = 'jUploadForm' + id;

        if (s.global && !jQuery.active++) {
            // Watch for a new set of requests
            jQuery.event.trigger("ajaxStart");
        }
        var requestDone = false;
        // Create the request object
        var xml = {};
        if (s.global) {
            jQuery.event.trigger("ajaxSend", [xml, s]);
        }

        var uploadCallback = function(isTimeout) {
            // Wait for a response to come back 
            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 (s.success) {
                            // ifa local callback was specified, fire it and pass it the data
                            s.success(data, status);
                        };
                        if (s.global) {
                            // Fire the global callback
                            jQuery.event.trigger("ajaxSuccess", [xml, s]);
                        };
                    } else {
                        jQuery.handleError(s, xml, status);
                    }

                } catch(e) {
                    status = "error";
                    jQuery.handleError(s, xml, status, e);
                };
                if (s.global) {
                    // The request was completed
                    jQuery.event.trigger("ajaxComplete", [xml, s]);
                };

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

                if (!requestDone) {
                    // Check to see ifthe request is still happening
                    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) {
                form.encoding = 'multipart/form-data';
            } else {
                form.enctype = 'multipart/form-data';
            }
            jQuery(form).submit();

        } catch(e) {
            jQuery.handleError(s, xml, null, e);
        }
        if (window.attachEvent) {
            document.getElementById(frameId).attachEvent('onload', uploadCallback);
        } else {
            document.getElementById(frameId).addEventListener('load', uploadCallback, false);
        }
        return {
            abort: function() {}
        };

    },

    uploadHttpData: function(r, type) {
        var data = !type;
        data = type == "xml" || data ? r.responseXML: r.responseText;
        // ifthe type is "script", eval it in global context
        if (type == "script") {
            jQuery.globalEval(data);
        }

        // Get the JavaScript object, ifJSON is used.
        if (type == "json") {
            eval("data = " + data);
        }

        // evaluate scripts within html
        if (type == "html") {
            jQuery("<div>").html(data).evalScripts();
        }

        return data;
    }
});