Getting Started with ReactJS Uploadbox

9 Mar 202313 minutes to read

This section explains briefly about how to create an Uploadbox in your application with Angular 2. Essential JavaScript Uploadbox widget provides support to upload files or photos within your web page. From the following guidelines, you can learn how to upload the files that are used in a Resume Upload scenario. This helps you to restrict some file extensions when you upload the resume in server by using Uploadbox control.

The following screenshot demonstrates the functionality of Uploadbox with the file extension.

In the above screenshot, you can upload a resume that allows .txt files. This helps you to avoid unsupported resume formats getting uploaded in a server.

NOTE

To get upload the file, you should either run this sample in Visual Studio IDE or host in local IIS.

Create Uploadbox widgets in React JS

Essential JavaScript Uploadbox widget basically renders built-in features like upload multiple files, and deletes the files from Uploadbox. You can know the status of uploading the file whether it is completed or failed and you can retry uploading the files. You can easily create the Uploadbox widget by using the following steps.

You can create a React application and add necessary scripts and styles with the help of the given React Getting Started Documentation.

Create a JSX file for rendering Uploadbox component using <EJ.Uploadbox> syntax. Add required properties to it in <EJ.Uploadbox> tag element

JS

var DefaultUploadbox = React.createClass({
    render: function () {
        return (
            <div id="tooltip_default">
                <div class="posupload">Select a file to upload </div>
                <EJ.Uploadbox id="UploadDefault"></EJ.Uploadbox>
            </div>
           );
        }
   });
ReactDOM.render(<DefaultUploadbox />, document.getElementById('uploadbox-default'));

Define an HTML element for adding Uploadbox in the application and refer the JSX file.

HTML

<div id="uploadbox-default"></div>
<script src="app/uploadbox/default.js">

CSS

<style>
       #targetElement {
        width: 500px;
        height: 500px;
        margin: 0 auto;
        }

       #UploadDefault {
        margin: 0 auto;
      }
    </style>

Create a new handler file (.ashx) and save it as saveFiles.ashx and then copy the following code into it.

C#

SaveFiles.ashx

    public void ProcessRequest(HttpContext context)
    {
        string targetFolder = HttpContext.Current.Server.MapPath("uploadfiles");
        if (!Directory.Exists(targetFolder))
        {
            Directory.CreateDirectory(targetFolder);
        }
        HttpRequest request = context.Request;
        HttpFileCollection uploadedFiles = context.Request.Files;
        if (uploadedFiles != null && uploadedFiles.Count > 0)
        {
            for (int i = 0; i < uploadedFiles.Count; i++)
            {
                if (uploadedFiles[i].FileName != null && uploadedFiles[i].FileName != "")
                {
                    string fileName = uploadedFiles[i].FileName;
                    int indx = fileName.LastIndexOf("\\");
                    if (indx > -1)
                    {
                        fileName = fileName.Substring(indx + 1);
                    }
                    uploadedFiles[i].SaveAs(targetFolder + "\\" + fileName);
                }
            }
        }
    }

Create a new handler file (.ashx) and save it as removeFiles.ashx and then copy the following code into it.

C#

removeFiles.ashx

    public void ProcessRequest(HttpContext context)
    {
        System.Collections.Specialized.NameValueCollection s = context.Request.Params;
        string fileName = s["fileNames"];
        string targetFolder = HttpContext.Current.Server.MapPath("uploadfiles");
        if (Directory.Exists(targetFolder))
        {
            string physicalPath = targetFolder + "\\" + fileName;
            if (System.IO.File.Exists(physicalPath))
            {
                System.IO.File.Delete(physicalPath);
            }
        }
    }

Add the following code example to assign saveUrl and removeUrl for Uploadbox

HTML

var DefaultUploadbox = React.createClass({
    render: function () {
        return (
            <div id="tooltip_default">
                <div class="posupload">Select a file to upload </div>
                <EJ.Uploadbox id="UploadDefault" saveUrl= {savefiles} removeUrl= {removefiles}></EJ.Uploadbox>
            </div>
           );
        }
   });
ReactDOM.render(<DefaultUploadbox />, document.getElementById('uploadbox-default'));

The following screenshot displays an Uploadbox control.

After you upload the files, the following screen shot is displayed.

NOTE

The above screenshot displays the Uploadbox control that shows the files are uploaded successfully.

Set Restriction for File Extension

In a real-time scenario, some file extensions are restricted. You can allow files and restrict files by using the following two properties extensionsAllow and extensionsDeny enabled in Uploadbox.

NOTE

The SaveUrl and RemoveUrl are the same as above (see step 4)

Add input elements to create elements for file extension.

NOTE

Add the following input elements and two button elements to give file extensions that should support uploading.

JS

var DefaultUploadbox = React.createClass({
    function onClickAllow(args){
        var uploadobject = $("#uploadDefault").data("ejUploadbox");
        uploadobject.option('extensionsAllow', $("#fileallow").val());
        uploadobject.option('extensionsDeny', "");
    }
    function onclickDeny(){
        var uploadobject = $("#uploadDefault").data("ejUploadbox");
        uploadobject.option('extensionsAllow', "");
        uploadobject.option('extensionsDeny', $("#filedeny").val());
    }
    render: function () {
        return (
            <div id="uploadbox_default"><table id="uploadTable">
        <tr>
            <td>
                Extensions:
            </td>

        </tr>
        <tr>
            <td>
                <input type="text" id="fileallow" class="ejinputtext" placeholder="Format" />
                <input ej-button type="submit" name="allow" value="Allow" click={onClickAllow} />
            </td>

        </tr>
        <tr>
            <td>
                <input type="text" id="filedeny" class="ejinputtext" placeholder="Format" />
                <input ej-button type="submit" name="deny" value="Deny" click={onclickDeny} />
            </td>
            <td>
                <div>Select a file to upload</div>
                <div style="width:100px;height:35px;"> 
                <EJ.Uploadbox id="UploadDefault" saveUrl= {savefiles} removeUrl= {removefiles}></EJ.Uploadbox>
            </td>
            </tr>
        </table>
        </div>
           );
        }
   });
ReactDOM.render(<DefaultUploadbox />, document.getElementById('uploadbox-default'));

Add the given styles to display the Uploadbox with margin alignments.

CSS

<style>
      #targetElement {
        width: 520px;
        height: 500px;
        margin: 0 auto;
       }
      #UploadDefault {
        float: right;
      }
      #uploadTable {
        width: 100%;
       }
      #fileallow, #filedeny {
        width: 150px;
        height: 20px;
        padding: 5px;
      }
    </style>

NOTE

You can restrict one or more files at a time by giving it as .html,.txt

The following screenshot displays an Uploadbox control with the file extension.

The above screenshot shows the Uploadbox that allows “.txt” file formats. You can give number of file formats in both allow and deny textbox elements.

Upload Multiple Files

You can click the Browse button and select files to upload multiple files in Uploadbox control. You can see the selected files in Uploadbox control and you can upload all the files.

The following screenshot displays an Uploadbox control with multiple files.