DropzoneJS nodejs example code

dropzone example.js

//helper to get a file extension
 String.prototype.getExtension = function() {
	var basename = this.split(/[\\/]/).pop(),  // extract file name from full path ...
											// (supports `\\` and `/` separators)
		pos = basename.lastIndexOf(".");       // get last position of `.`

	if (basename === "" || pos < 1)            // if file name is empty or ...
		return "";                             //  `.` not found (-1) or comes first (0)

	return basename.slice(pos + 1);            // extract extension ignoring `.`
};

Array.prototype.indexOf || (Array.prototype.indexOf = function(d, e) {
	var a;
	if (null == this) throw new TypeError('"this" is null or not defined');
	var c = Object(this),
		b = c.length >>> 0;
	if (0 === b) return -1;
	a = +e || 0;
	Infinity === Math.abs(a) && (a = 0);
	if (a >= b) return -1;
	for (a = Math.max(0 <= a ? a : b - Math.abs(a), 0); a < b;) {
		if (a in c && c[a] === d) return a;
		a++
	}
	return -1
});

let files = [];
Dropzone.options.uploadzone = {
	url:'/upload',
	addRemoveLinks: true,
	paramName: 'attachment',
	maxFilesize: 10,
	maxFiles: 5,
	dictDefaultMessage: 'Drag an file here to upload, or click to select',
	acceptedFiles: '.png, .jpg, .jpeg, .gif, .pdf, .zip, .docx, .doc',
	renameFilename: (name) => {
		return mail_id + '-' + name;
	},
	init: function() {
		let myDropzone = this;
		let xhr = undefined;

		this.on('success', function(file, resp){
			files.push(resp);
		});
		this.on('error',  function (file, error, xhr){
			console.log(error);
		});
		this.on('removedfile', function(file){ //delete the file
			let file_index = files.find((n) => { return n.originalname == mail_id + '-' +file.name });
			xhr = $.ajax({
				url: "http://localhost:3000/uploads/delete",
				type: "POST",
				data: {file : file_index}
			});
			files.splice(files.indexOf(file_index), 1);
		});

		let fn = () =>
		{
			if(xhr != undefined && xhr.readyState != 4)
				xhr.abort(); 
		};
		setInterval(fn, 500);
	},
	accept: function(file, done) {
		let ext = file.name.toString().getExtension();
		if( ext == 'pdf' || ext == 'png' || ext == 'png'|| ext == 'jpeg' ||
			ext == 'docx' || ext == 'doc' || ext == 'xlxs' || ext == 'jpg'
		){
			done();
		}
		else
			done('Invalid file type');
	}
};