Allow changing CDN provider by user to solve problem where default CDN is blocked countrywise

[cderv]

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Discussed in #12109

^{Originally posted by skyfroger February 18, 2025}

Description

I have issues reaching cdn.jsdelivr.net in my country. So I am getting errors while trying to render MathJax formulast and inster OJS interactive elements. Is there are an option to change default CDN provider?

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Context

I believe Quarto should try to be friendly as possible with users wherever they are. Currently, cdn.jsdelivr.net is used by default in several places

Mathjax / KaTeX

quarto-cli/src/command/render/template.ts

Lines 225 to 235 in ec8cd58

	const math = format.pandoc[kHtmlMathMethod];
	if (math === undefined || math === "mathjax") {
	return {
	method: "mathjax",
	url: "https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml-full.js",
	};
	} else if (math === "katex") {
	return {
	method: "katex",
	url: "https://cdn.jsdelivr.net/npm/[email protected]/dist/",
	};

This one can already be customized through html-math-method configuration by providing a full new URL

Search with Algolia

It is using cdn.jsdelivr.net by default with no customization

quarto-cli/src/project/types/website/website-search.ts

Lines 695 to 718 in ec8cd58

	function autocompleteInsightsPluginScript(cookieConsent: boolean) {
	return scriptTagWithConsent(
	cookieConsent,
	"tracking",
	"",
	"https://cdn.jsdelivr.net/npm/@algolia/autocomplete-plugin-algolia-insights",
	);
	}
	function algoliaSearchInsightsScript(cookieConsent: boolean) {
	return scriptTagWithConsent(
	cookieConsent,
	"tracking",
	`var ALGOLIA_INSIGHTS_SRC = "https://cdn.jsdelivr.net/npm/search-insights/dist/search-insights.iife.min.js";
	!function(e,a,t,n,s,i,c){e.AlgoliaAnalyticsObject=s,e[s]=e[s]||function(){
	(e[s].queue=e[s].queue||[]).push(arguments)},i=a.createElement(t),c=a.getElementsByTagName(t)[0],
	i.async=1,i.src=n,c.parentNode.insertBefore(i,c)
	}(window,document,"script",ALGOLIA_INSIGHTS_SRC,"aa");`,
	);
	}
	const kAlogioSearchApiScript =
	`<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/algoliasearch-lite.umd.js"></script>
	`;

OJS

Note

EDIT: For OJS this is not possible as we inherit from ObservableHQ directly (#12120 (comment))

I see

quarto-cli/src/resources/formats/html/ojs/quarto-ojs-runtime.js

Lines 256 to 257 in ec8cd58

	function resolveFrom(origin = "https://cdn.jsdelivr.net/npm/", mains = ["unpkg", "jsdelivr", "browser", "main"]) {
	if (!/\/$/.test(origin)) throw new Error("origin lacks trailing slash");

which probably is related to how NPM package are served: https://quarto.org/docs/interactive/ojs/libraries.html#npm

This is the real problem encountered in #12109

This would be another part to make it configurable if possible 🤷‍♂

Current workaround

Currently doing a post processing to replace the CDN used in quarto-os-runtime.js or other file

• How do I change default CDN provider from cdn.jsdelivr.net to another option? #12109 (reply in thread)

[cscheid]

We don't fully control this, unfortunately. This is coming from the ObservableHQ source code directly. We would have to fork their implementation and maintain the option forever. I don't think we can afford to do that.

[cderv]

Thanks for the additional information. Then post processing workaround seems to be the good solution here of OJS.

So

• for OJS this is not possible and could be documented as limitation.
• For algolia, we can probably add a configuration like with math.