Source code

Revision control

Copy as Markdown

Other Tools

<!doctype html>
<meta charset="utf-8">
<div id="before-print">Before print</div>
<canvas id="canvas" width="100" height="100"></canvas>
onload = function() {
// window.print() is special until after the load event is finished firing.
setTimeout(function() {
// This fires a timer which would trigger a navigation and prevent the
// test from completing if it happens during window.print().
let meta = document.createElement("meta");
meta.setAttribute("http-equiv", "refresh");
meta.setAttribute("content", "0; url=/unlikely-to-be-found");
// This one should block until we're done printing, and block the
// navigation too.
document.body.insertAdjacentHTML('beforeend', `<div id="after-first-print">After first print</div>`);
let canvas = document.getElementById("canvas");
canvas.mozPrintCallback = function() {};
// This one shouldn't, because the print callbacks need to run.
document.body.insertAdjacentHTML('beforeend', `<div id="after-second-print">After second print</div>`);
}, 0);