兼容ie的jquery ajax文件上传

Ajax文件上传插件很多，但兼容性各不一样，许多是对ie不兼容的，另外项目中是要求将网页内容嵌入到桌面端应用的，这样就不允许带flash的上传插件了，如：jquery uploadify。。。悲剧

对于Ajax文件上传，大体是有：

　　1、创建一个input type="file" 的文件上传按钮，根据其id监听绑定其change事件，在事件中用jquery创建一个iframe，嵌入添加隐藏form，同时创建input type="file"，id相同的文件上传按钮，并传入其他需要提交的数据，然后提交，提交完成后移除一个input type="file"，这样用bind或on的绑定就对新的input 框失效，需要重新再绑定一次change事件，以前的jquery是可以使用live函数代替的，现在只能在文件上传成功后再绑定一次change事件。

 $(function() {
     uploadFile("fileData",'cn.ftiao.cm.model.LiveCourse','',"CI");
 });

 function uploadFile(id,classFullName,jsonStrValue,preFileName){
     $("#"+id).on("change", function(){
         // 上传方法
         $.ajaxFileUpload({
             url:$("#"+id).attr("data-url-upload"),            //需要链接到服务器地址
             secureuri:false,
             type:"post",
             fileElementId:id,                        //文件选择框的id属性
             dataType: 'json',
             data:{
                 "classFullName":classFullName,
                 "jsonStrValue":"",
                 "preFileName":preFileName
             },
             //服务器返回的格式，可以是json
             success: function (data, status){          //相当于java中try语句块的用法
                 $("#courseIconImg").attr("src",$(".ctx").val()+"/images/img-class.png");
                 alert("hello");
                 //先将原有的上传展示清除
                 $("#" + id).nextAll("span").remove();
                 $("#courseIcon").val(data.outputFileName);
 //                    $("#coursewareFile").val(data.outputFileName);
                     var uploadHtml = "<span id='"+data.outputPreFileName+"_livelesson_div' style='color:#FFFFFF;'>";
                     uploadHtml +=  data.fileUploadName ;
                     uploadHtml += "<a  name='_LIVELESSON_PRIVIEW'>&nbsp;预览 &nbsp;</a><a  name='_LIVELESSON_DEL'>&nbsp;删除&nbsp;</a>";
                     uploadHtml += "</span>";
 //                    $("#"+id).parents("li").append(uploadHtml);
                     uploadFile("fileData",'cn.ftiao.cm.model.LiveCourse','',"CI");
             },
             error: function (data, status, e)    //相当于java中catch语句块的用法
             {
                 alert(e);
             }
         });
     });
     return false;
 }

　　2、创建一个 input type="file"的按钮，监听其click事件，然后创建iframe，隐藏form，隐藏form里有个 input type="file"的文件上传框，模拟点击click，弹出文件选择框，选择完文件后上传。此方法在ie下会报 “权限不足” 问题。

下面是ajaxFileUpload 插件

 jQuery.extend({

     handleError: function(s, xhr, status, e) {
         // If a local callback was specified, fire it
         if (s.error) {
             s.error.call(s.context || window, xhr, status, e);
         }

         // Fire the global callback
         if (s.global) {
             (s.context ? jQuery(s.context) : jQuery.event).trigger("ajaxError", [xhr, s, e]);
         }
     },
     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));
         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"){
             if (data.indexOf("<") >= 0) {
                 data = jQuery.parseJSON(jQuery(data).text());
             }
             else {
                 eval("data = " + data);  /*Bug  fixed by under */
             }
          }
         // evaluate scripts within html
         if ( type == "html" )
             jQuery("<div>").html(data).evalScripts();

         return data;
     }
 })