Function to print some HTML content on NW.js using a iFrame

iframe-print.js

function printR(htmlContent) {
	let doc = nw.Window.get().window.document;
	let iframe = doc.createElement("iframe");
	iframe.style.display = 'none';
	doc.body.appendChild(iframe);
		
	iframe.onload = () => {
		console.log('loaded');
		if (typeof htmlContent === 'function') {
			htmlContent(iframe);
		} else {
			iframe.contentDocument.body.innerHTML = htmlContent;
		}
		iframe.focus();
		iframe.contentWindow.print({ autoprint: false });
		iframe.contentWindow.onafterprint = function(){
			doc.body.removeChild(iframe);
		}
	};
	iframe.src = 'about:blank';
}