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