The uploader component validate the selected files size and extension using the allowedExtentions, minFileSize and maxFileSize properties. The files can be validated before uploading to the server and can be ignored on uploading. Also, you can validate the files by setting the HTML attributes to the original input element. The validation process occurs on drag-and-drop the files also.
You can allow the specific files alone to upload using the allowedExtentions property. The extension can be represented as collection by comma separators. The uploader component filters the selected or dropped files to match against the specified file types and processes the upload operation. The validation happens when you specify value to inline attribute to accept the original input element.
// initialize Uploader component
var uploadObj = new ej.inputs.Uploader({
asyncSettings: {
saveUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Save',
removeUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Remove'
},
allowedExtensions: '.jpg,.png'
});
uploadObj.appendTo('#fileupload');<!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/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-popups/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-buttons/styles/material.css" rel="stylesheet">
<script src="https://cdn.syncfusion.com/ej2/21.2.3/dist/ej2.min.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>The uploader component allows you to validate the files based on its size. The validation helps to restrict uploading large files or empty files to the server. The size can be represented in bytes. By default, the uploader component allows you to upload minimum file size as 0 byte and maximum file size as 28.4 MB using using the minFileSize and maxFileSize properties.
// Initialize the uploader component
var uploadObj = new ej.inputs.Uploader({
asyncSettings: {
saveUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Save',
removeUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Remove'
},
minFileSize: 10000,
maxFileSize: 1500000
});
uploadObj.appendTo('#fileupload');<!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/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-popups/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-buttons/styles/material.css" rel="stylesheet">
<script src="https://cdn.syncfusion.com/ej2/21.2.3/dist/ej2.min.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>You can restrict uploading the maximum number of files using the selected event. In the selected event arguments, you can get the currently selected files details using the getFilesData(). You can modify the files details and assign the modified file list to the eventArgs.modifiedFilesData.
ej.base.enableRipple(true);
var dropElement = document.getElementsByClassName('control-fluid')[0];
// Initialize the control with file validation
var uploadObj = new ej.inputs.Uploader({
autoUpload: false,
minFileSize: 10000,
allowedExtensions: '.doc, .docx, .xls, .xlsx',
asyncSettings: {
saveUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Save',
removeUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Remove'
},
selected: onFileSelected,
success: onUploadSuccess,
dropArea: dropElement
});
uploadObj.appendTo('#validation');
function onFileSelected(args) {
// Filter the 5 files only to showcase
args.filesData.splice(5);
var filesData = uploadObj.getFilesData();
var allFiles = filesData.concat(args.filesData);
if (allFiles.length > 5) {
for (var i = 0; i < allFiles.length; i++) {
if (allFiles.length > 5) {
allFiles.shift();
}
}
args.filesData = allFiles;
// set the modified custom data
args.modifiedFilesData = args.filesData;
}
args.isModified = true;
}
function onUploadSuccess(args) {
var _this = this;
var li = this.uploadWrapper.querySelector('[data-file-name="' + args.file.name + '"]');
if (args.operation === 'upload') {
li.querySelector('.e-file-delete-btn').onclick = function () {
generateSpinner(_this.uploadWrapper);
};
li.querySelector('.e-file-delete-btn').onkeydown = function (e) {
if (e.keyCode === 13) {
generateSpinner(e.target.closest('.e-upload'));
}
};
}
else {
ej.popups.hideSpinner(this.uploadWrapper);
ej.base.detach(this.uploadWrapper.querySelector('.e-spinner-pane'));
}
}
function generateSpinner(targetElement) {
ej.popups.createSpinner({ target: targetElement, width: '25px' });
ej.popups.showSpinner(targetElement);
}<!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/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-popups/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-buttons/styles/material.css" rel="stylesheet">
<script src="https://cdn.syncfusion.com/ej2/21.2.3/dist/ej2.min.js" type="text/javascript"></script>
</head>
<body>
<div id="container">
<input type="file" id="validation" 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>You can validate the duplicate files before uploading to server using the selected event. Compare the selected files with the existing files data and filter the file list by removing the duplicate files.
ej.base.enableRipple(true);
// Initialize the control with file validation
var uploadObj = new ej.inputs.Uploader({
autoUpload: false,
asyncSettings: {
saveUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Save',
removeUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Remove'
},
selected: onFileSelect,
});
uploadObj.appendTo('#validation');
function onFileSelect(args) {
var existingFiles = this.getFilesData();
for (var i = 0; i < args.filesData.length; i++) {
for (var j = 0; j < existingFiles.length; j++) {
if (!ej.base.isNullOrUndefined(args.filesData[i])) {
if (existingFiles[j].name == args.filesData[i].name) {
args.filesData.splice(i, 1);
}
}
}
}
existingFiles = existingFiles.concat(args.filesData);
args.modifiedFilesData = existingFiles;
args.isModified = true;
}<!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/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-popups/styles/material.css" rel="stylesheet">
<link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-buttons/styles/material.css" rel="stylesheet">
<script src="https://cdn.syncfusion.com/ej2/21.2.3/dist/ej2.min.js" type="text/javascript"></script>
</head>
<body>
<div id="container">
<input type="file" id="validation" 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>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.