How to upload files asynchronously with jQuery

To upload file asynchronously with Jquery use below steps:

step 1 In your project open Nuget manager and add package (jquery fileupload(only you need to write it in search box it will come up and install it.)) URL: https://github.com/blueimp/jQuery-File-Upload

step 2 Add below scripts in the HTML files, which are already added to the project by running above package:

• jquery.ui.widget.js
• jquery.iframe-transport.js
• jquery.fileupload.js

step 3 Write file upload control as per below code:

<input id="upload" name="upload" type="file" />

step 4 write a js method as uploadFile as below:

function uploadFile(element) {

            $(element).fileupload({

                dataType: 'json',
                url: '../DocumentUpload/upload',
                autoUpload: true,
                add: function (e, data) {           
                  // write code for implementing, while selecting a file. 
                  // data represents the file data. 
                  //below code triggers the action in mvc controller
                  data.formData =
                                    {
                                     files: data.files[0]
                                    };
                  data.submit();
                },
                done: function (e, data) {          
                   // after file uploaded
                },
                progress: function (e, data) {

                   // progress
                },
                fail: function (e, data) {

                   //fail operation
                },
                stop: function () {

                  code for cancel operation
                }
            });

        };

step 5 In ready function call element file upload to initiate the process as per below:

$(document).ready(function()
{
    uploadFile($('#upload'));

});

step 6 Write MVC controller and Action as per below:

public class DocumentUploadController : Controller
    {       

        [System.Web.Mvc.HttpPost]
        public JsonResult upload(ICollection<HttpPostedFileBase> files)
        {
            bool result = false;

            if (files != null || files.Count > 0)
            {
                try
                {
                    foreach (HttpPostedFileBase file in files)
                    {
                        if (file.ContentLength == 0)
                            throw new Exception("Zero length file!");                       
                        else 
                            //code for saving a file

                    }
                }
                catch (Exception)
                {
                    result = false;
                }
            }


            return new JsonResult()
                {
                    Data=result
                };


        }

    }

HTML5 Upload Solution

With HTML5 you CAN make file uploads with Ajax and jQuery. Not only that, you can do file validations (name, size, and MIME-type) or handle the progress event with the HTML5 progress tag (or a div). Recently I had to make a file uploader, but I didn't want to use Flash nor Iframes or plugins and after some research I came up with the solution.

The HTML:

<form enctype="multipart/form-data">
    <input name="file" type="file" />
    <input type="button" value="Upload" />
</form>
<progress></progress>

First, you can do some validation if you want. For example, in the onChange event of the file:

$(':file').change(function(){
    var file = this.files[0];
    var name = file.name;
    var size = file.size;
    var type = file.type;
    //Your validation
});

Now the Ajax submit with the button's click:

$(':button').click(function(){
    var formData = new FormData($('form')[0]);
    $.ajax({
        url: 'upload.php',  //Server script to process data
        type: 'POST',
        xhr: function() {  // Custom XMLHttpRequest
            var myXhr = $.ajaxSettings.xhr();
            if(myXhr.upload){ // Check if upload property exists
                myXhr.upload.addEventListener('progress',progressHandlingFunction, false); // For handling the progress of the upload
            }
            return myXhr;
        },
        //Ajax events
        beforeSend: beforeSendHandler,
        success: completeHandler,
        error: errorHandler,
        // Form data
        data: formData,
        //Options to tell jQuery not to process data or worry about content-type.
        cache: false,
        contentType: false,
        processData: false
    });
});

Now if you want to handle the progress.

function progressHandlingFunction(e){
    if(e.lengthComputable){
        $('progress').attr({value:e.loaded,max:e.total});
    }
}

As you can see, with HTML5 (and some research) file uploading not only becomes possible but super easy. Try it with Google Chrome as some of the HTML5 components of the examples aren't available in every browser.

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