Script tag running before DOM is loaded
I believe the script tag is running before the DOM elements are loaded. How would I go about waiting for the elements to be loaded first? I’ve tried wrapping the script tag’s content in window.onload = () => {} but no luck. I’ve also tried <body onload="myFunc()">.
My logic is to hide the React content in root if the browser is Edge/IE and show the unsupportedBrowser content to let the user know that this browser is not supported.
Note this only happens in IE.
<html>
<body>
<div id="root">React Content</div>
<div id="unsupportedBrowser" style="display: none;">
Microsoft Edge is NOT supported.
</div>
<script type="text/javascript" defer>
document.addEventListener("DOMContentLoaded", function(){
if (window.document.documentMode || window.navigator.userAgent.indexOf("Edge") > -1) {
alert("Edge browser");
document.getElementById("root").style.display = "none"; //ERROR here, rest doesn't run
document.getElementById("unsupportedBrowser").style.display = "block";
// do other things
};
});
</script>
</body>
</html>Answer
Maybe React is giving you a hard time, since it gets still executed when you include the source for it.
<html>
<body>
<script type="text/javascript">
document.addEventListener("DOMContentLoaded", function(){
if (window.navigator.userAgent.indexOf("Edge") > -1) {
alert("Edge browser");
document.body.innerHTML = '<div id="unsupportedBrowser" style="display: none;">Microsoft Edge is NOT supported.</div>'
}else{
var root = document.createElement("div");
root.setAttribute("id", "root");
document.body.appendChild(root);
var react_script = document.createElement("script");
react_script.setAttribute("src", "your_script");
document.body.appendChild(react_script);
}
});
</script>
</body>
</html>
A side note: I don’t get why you exclude the Edge browser. Edge != Internet Explorer. These days all major browser support the standard browser APIs. For browser compatibility you should also use Babel to transpile it down.