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@itsjohncs

itsjohncs/freezes.htm

Created September 17, 2021 01:21
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One works and the other freezes the browser... Why?
Raw
freezes.htm
<!DOCTYPE html>
<html>
<head>
<script>
let _openCVPromise = null;
function getOpenCV() {
if (_openCVPromise === null) {
_openCVPromise = new Promise(function(resolve, reject) {
const script = document.createElement("script");
script.setAttribute("src", "https://shmeppy-external-js.sfo3.cdn.digitaloceanspaces.com/opencv-4.5.3.js");
script.addEventListener("load", function() {
resolve(window.cv); // !! Only difference
});
document.head.appendChild(script);
});
}
return _openCVPromise;
}
</script>
</head>
<body>
<button onClick="console.log(getOpenCV())">load</button>
<button onClick="console.log('OpenCV loaded', !!window.cv)">Beep</button>
</body>
</html>
Raw
works-fine.htm
<!DOCTYPE html>
<html>
<head>
<script>
let _openCVPromise = null;
function getOpenCV() {
if (_openCVPromise === null) {
_openCVPromise = new Promise(function(resolve, reject) {
const script = document.createElement("script");
script.setAttribute("src", "https://shmeppy-external-js.sfo3.cdn.digitaloceanspaces.com/opencv-4.5.3.js");
script.addEventListener("load", function() {
resolve(); // !! Only difference
});
document.head.appendChild(script);
});
}
return _openCVPromise;
}
</script>
</head>
<body>
<button onClick="console.log(getOpenCV())">load</button>
<button onClick="console.log('OpenCV loaded', !!window.cv)">Beep</button>
</body>
</html>
@itsjohncs
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Ahhhh that makes sense. Thank you for solving this mystery.

Though I have a new mystery. I forget why I made this gist. Where did you find a link to this?

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