Best way to include custom JavaScript in AMP

Question

I read all documentation about script tag but I cannot find how to include a custom JavaScript in AMP HTML.

I know the <script> tag is prohibited unless its type is application/ld+json.

There are default AMP HTML runtime components and extended components which contain specific form for different components, but I could not find a specific one for custom JavaScript.

Here is the script tag I want to include in AMP HTML;

<script src="https://arifkarim.com/widget/layouts/global/js/legaltext.js"></script>

Answer 1

The whole point of AMP is to only allow a subset of web technologies to stop your page being slow.

Javascript is often the cause of slow websites and so AMP pages do not allow them (except for the AMP scripts themselves), though they've tried to fill in the gap this leaves with amp components which are specially written to not be slow.

So if you want to use Javascript you've several choices:

1. Don't use AMP. Nobody is forcing this on you.
2. Remove the script tag from your amp document and live without that functionality.
3. Find an amp-component which does the same as your JavaScript and use that instead. Not having a clue what legaltext.js I would guess by the name it displays some legal text like a cookie notice so maybe the amp-user-notification widget would work instead?
4. Use your Javascript in an amp iframe. These are allowed in amp pages but will presumable be loaded with a lower priority to ensure they don't slow down the main page.

Answer 2

<script> tags are generally not allowed in AMP. There are a handful of external javascript files, built as part of the AMP project, which are allowed and even required in some cases. Other than those, javascript is not allowed. Custom script tags are not possible with AMP.