Achieve Invisible Upload in JavaScript (ES5) Uploader control

14 Apr 2021 / 1 minute to read

You can achieve the invisible upload feature by using the selected event in uploader component. Refer to the following example.

Source

Preview

index.js

index.html

index.css

// initialize Uploader component
var uploadObject = new ej.inputs.Uploader({
    asyncSettings: {
        saveUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Save',
        removeUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Remove'
    },
    selected : onupload,
    locale: 'en-US',
    allowedExtensions: '.png, .jpg, .jpeg'
});

// render initialized Uploader
uploadObject.appendTo('#fileupload');

function onupload(args) {    
    for(var i = 0; i< args.filesData.length ; i++){
        var liparentDiv = createElement('div',  { className: 'image-list'});
        var liImage = createElement('img',  { className: 'image'});
        liparentDiv.appendChild(liImage);
        readURL(liImage, args.filesData[i]);
        document.getElementById('preview').appendChild(liparentDiv);
    }
    args.cancel=true;
}

function readURL(liImage, file) {
    var imgPreview = liImage;
    var imageFile = file.rawFile;
    var reader = new FileReader();
    reader.addEventListener( 'load', () => {
        imgPreview.src = reader.result;
    }, false);
    if (imageFile) {
        reader.readAsDataURL(imageFile);
    }
};

<!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="//cdn.syncfusion.com/ej2/ej2-base/styles/material.css" rel="stylesheet">
    <link href="//cdn.syncfusion.com/ej2/ej2-inputs/styles/material.css" rel="stylesheet">
    <link href="//cdn.syncfusion.com/ej2/ej2-popups/styles/material.css" rel="stylesheet">
    <link href="//cdn.syncfusion.com/ej2/ej2-buttons/styles/material.css" rel="stylesheet">
    
    
<script src="https://cdn.syncfusion.com/ej2/dist/ej2.min.js" type="text/javascript"></script>
</head>
<body>
    
    <div id="preview"></div>
    <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;
  margin: 10px;
}

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

#preview {
  border: 2px dashed #ddd;
  padding: 15px;
}

.image-list {
  width: 134px;
  height: 117px;
  margin-right: 4px;
  border: 1px solid lightgrey;
  display: inline-block;
}

.image {
  width: 134px;
  height: 117px;
  margin-right: 4px;
  display: inline-block;
}

.e-control {
  border : 0;
}

.e-control ul {
  border: 1px solid #ddd;
}

.e-control .e-file-select,
.e-control .e-file-drop {
  display: none;
}