[Javascript]异步上传文件

页面引用了别人写的代码，但是找不到原作者

1.网页包含以下两个文件

<script type="text/javascript" src="__PUBLIC__/js/jquery-1.10.2.min.js"></script><script type="text/javascript" src="__PUBLIC__/js/jquery.form.min.js"></script>

2.前台代码

<form  action="ajax_goods.php" id="form1" name="form1"  method="post" enctype="multipart/form-data"><input type="file" name="FileInput"   id="FileInput"  /><input type="submit" value="上传" /><div id="output"></div></form></center><script type="text/javascript">$(document).ready(function() {var options = { target:   '#output',   // target element(s) to be updated with server response beforeSubmit:  beforeSubmit,  // pre-submit callback success:       afterSuccess,  // post-submit callback uploadProgress: OnProgress, //upload progress callback  resetForm: true        // reset the form after successful submit }; $('#form1').submit(function(){ $(this).ajaxSubmit(options);  // always return false to prevent standard browser submit and page navigation return false; });//function after succesful file upload (when server response)function afterSuccess(){//$('#submit-btn').show(); //hide submit button//$('#loading-img').hide(); //hide submit button//$('#progressbox').delay( 1000 ).fadeOut(); //hide progress bar}//function to check file size before uploading.function beforeSubmit(){    //check whether browser fully supports all File API   if (window.File && window.FileReader && window.FileList && window.Blob){if( !$('#FileInput').val()) //check empty input filed{$("#output").html("Are you kidding me?");return false}var fsize = $('#FileInput')[0].files[0].size; //get file sizevar ftype = $('#FileInput')[0].files[0].type; // get file type//allow file types switch(ftype)        {            case 'image/png': case 'image/gif': case 'image/jpeg': case 'image/pjpeg':case 'text/plain':case 'text/html':case 'application/x-zip-compressed':case 'application/pdf':case 'application/msword':case 'application/vnd.ms-excel':case 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet':case 'video/mp4':                break;            default:                $("#output").html("<b>"+ftype+"</b> Unsupported file type!");return false        }//Allowed file size is less than 5 MB (1048576)if(fsize>5242880) {$("#output").html("<b>"+bytesToSize(fsize) +"</b> Too big file! <br />File is too big, it should be less than 5 MB.");return false}//$('#submit-btn').hide(); //hide submit button//$('#loading-img').show(); //hide submit button$("#output").html("");  }else{//Output error to older unsupported browsers that doesn't support HTML5 File API$("#output").html("Please upgrade your browser, because your current browser lacks some new features we need!");return false;}}//progress bar functionfunction OnProgress(event, position, total, percentComplete){    //Progress bar//$('#progressbox').show();   // $('#progressbar').width(percentComplete + '%') //update progressbar percent complete    //$('#statustxt').html(percentComplete + '%'); //update status text    //if(percentComplete>50)    //    {     //       $('#statustxt').css('color','#000'); //change status text to white after 50%     //   }}//function to format bites bit.ly/19yoIPOfunction bytesToSize(bytes) {   var sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];   if (bytes == 0) return '0 Bytes';   var i = parseInt(Math.floor(Math.log(bytes) / Math.log(1024)));   return Math.round(bytes / Math.pow(1024, i), 2) + ' ' + sizes[i];} });</script>

3.表单中action指向的文件就是异步提交过去的处理代码

后台代码：

        if(isset($_FILES["FileInput"]) && $_FILES["FileInput"]["error"]== UPLOAD_ERR_OK)        {            ############ Edit settings ##############            $UploadDirectory= 'D:/phpStudy/WWW/OurMemory/Uploads/'; //specify upload directory ends with / (slash)            ##########################################                    /*             Note : You will run into errors or blank page if "memory_limit" or "upload_max_filesize" is set to low in "php.ini".             Open "php.ini" file, and search for "memory_limit" or "upload_max_filesize" limit             and set them adequately, also check "post_max_size".             */                    //check if this is an ajax request           if (!isset($_SERVER['HTTP_X_REQUESTED_WITH'])){                die('this is not ajax request');            }                             //Is file size is less than allowed size.            if ($_FILES["FileInput"]["size"] > 5242880) {                die("File size is too big!");            }                    //allowed file type Server side check            switch(strtolower($_FILES['FileInput']['type']))            {                //allowed file types                case 'image/png':                case 'image/gif':                case 'image/jpeg':                case 'image/pjpeg':                case 'text/plain':                case 'text/html': //html file                case 'application/x-zip-compressed':                case 'application/pdf':                case 'application/msword':                case 'application/vnd.ms-excel':                case 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet':                case 'video/mp4':                    break;                default:                    die('Unsupported File!'); //output error            }                    $File_Name          = strtolower($_FILES['FileInput']['name']);            $File_Ext           = substr($File_Name, strrpos($File_Name, '.')); //get file extention            $Random_Number      = rand(0, 9999999999); //Random number to be added to name.            $NewFileName = $Random_Number.$File_Ext; //new file name                    if(move_uploaded_file($_FILES['FileInput']['tmp_name'], $UploadDirectory.$NewFileName ))            {                die('Success! File Uploaded.');            }else{                die('error uploading File!');            }                }        else        {            die('Something wrong with upload! Is "upload_max_filesize" set correctly?');        }