如何安全地加载外部 JavaScript 文件？

Question

Is there a safe way to load external JavaScript file? In a situation when the external or internal host/server/URL is NOT reachable?

I want to know how can I make sure the page is not slowing down - it can look bad or miss functionality (due to the script not loading correctly).

Is "async=true" is all you need to do?

Thanks

Answer 1

You could use the async and/or defer attributes.

• async , if the attribute is present, then the classic script will be fetched in parallel to parsing and evaluated as soon as it is available.
• defer will indicate to a browser that the script is meant to be executed after the document has been parsed

<script 
    type="application/javascript" 
    src="https://example.com/something.min.js" 
    async 
    defer>
</script>