clipboard.js

const clipboardWrite = (()=>{
	const callHandlers = [];
	window.addEventListener('copy', (e)=>{
		if (callHandlers.length <= 0) return;

		const handler = callHandlers.shift();
		return handler(e);
	});



	return function(data, mime = 'text/plain') {
		return new Promise((res, rej) => {
			// https://developer.mozilla.org/en-US/docs/Web/API/Clipboard
			// This will only available in modern browser and http sites
			/*
			if (window.navigator && navigator.clipboard) {
				const blob = new Blob([data], {type: mime});
				return navigator.clipboard.write([new ClipboardItem({[mime]: blob})]).then(res).catch(rej);
			}
			*/



			// Old fashioned style 
			callHandlers.push((evt)=>{
				evt.preventDefault();
				evt.clipboardData.setData(mime, data);
				setTimeout(res, 0);
			});

			setTimeout(()=>document.execCommand('copy'), 0);
		});
	};
})();