My code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=, initial-scale=1.0">
<link rel="stylesheet" href="./index.css">
<title>Youpotify</title>
</head>
<body>
<div class="download">
<div class="video">
<button id="video">Download this video</button>
</div>
<div class="playlist">
<button id="playlist">Download this playlist</button>
</div>
<div class="channel">
<button id="channel">Download this channel</button>
</div>
</div>
<script>
document.getElementById("video").addEventListener("click", () => {
document.getElementById("video").style.backgroundcolor = "red";
});
</script>
</body>
</html>
I loaded this addon on Temporary Extension and I click the button but the background color did not change.
I wanted to run my JavaScript file in firefox addon popup HTML file, but it didn't work.
There are a couple of potential issues here:
First, inline Javascript (inside <script></script> tags) is not permitted by default.
To include Javascript to your popup, you need to put it into a separate Javascript file and reference is with:
<script src="index.js"></script>
where your index.js is in the same folder and has your code:
document.getElementById("video").addEventListener("click", () => {
document.getElementById("video").style.backgroundColor = "red";
});
Second,
document.getElementById("video").style.backgroundcolor = "red";
has incorrect attribute, it should be style.backgroundColor with a capital C.