Validate image on drop in EJ2 JavaScript Uploader control

15 May 20235 minutes to read

The uploader component allows you to upload all type of images by setting *image/ ** to allowedExtensions property.

By default, the behavior is working with select a file using browse button. But, this behavior doesn’t support on drag and drop the files. You can handle this behavior manually using selected event by filtering the file types from application.

In the following example, validated image files using images/*. You are able to drag and drop the image files with extension of PNG, JPG, BPG, GIF and TIFF to upload it.

index.js
index.html
styles.css
// initialize Uploader component
var uploadObj = new ej.inputs.Uploader({
    asyncSettings: {
        saveUrl: 'https://services.syncfusion.com/js/production/api/FileUploader/Save',
        removeUrl: 'https://services.syncfusion.com/js/production/api/FileUploader/Remove'
    },
    autoUpload: false,
    allowedExtensions: 'image/*',
    selected: onSelect
});
uploadObj.appendTo('#fileupload');

function onSelect(args) {
    if (args.event.type === 'drop') {
        var allImages = ['png', 'jpg', 'jpeg', 'gif', 'tiff', 'bpg'];
        var files = args.filesData;
        var modifiedFiles = [];
        for (var i=0; i< files.length; i++){
            var file = files[i];
            if (allImages.indexOf(file.type) === -1) {
                file.status = 'File type is not allowed';
                file.statusCode = '0';
            }
            modifiedFiles.push(file);
        }
        args.isModified = true;
        args.modifiedFilesData = modifiedFiles.concat(uploadObj.filesData);
    }
}
<!DOCTYPE html><html lang="en"><head>
    <title>Essential JS 2 Uploader</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta name="description" content="Essential JS 2 Uploader Component">
    <meta name="author" content="Syncfusion">
    <link href="index.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-buttons/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/25.1.35/dist/ej2.min.js" type="text/javascript"></script>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
    
        <div id="container">
            <input type="file" id="fileupload" name="UploadFiles">
        </div>
    

<script>
var ele = document.getElementById('container');
if(ele) {
  ele.style.visibility = "visible";
}   
      </script>
<script src="index.js" type="text/javascript"></script>
</body></html>
#container {
  visibility: hidden;
}

#loader {
  color: #008cff;
  font-family: 'Helvetica Neue','calibiri';
  font-size: 14px;
  height: 40px;
  left: 45%;
  position: absolute;
  top: 45%;
  width: 30%;
}

You can also explore JavaScript File Upload feature tour page for its groundbreaking features. You can also explore our JavaScript File Upload example to understand how to browse the files which you want to upload to the server.