@expressive-code/plugin-collapsible-sections

A third-party plugin for Expressive Code, an engine for presenting source code on the web.

It adds a data-lang="<language>" attribute onto the root HTML element of the code block (usually the Frame <figure> element).

This can be styled with psuedo-elements to display the code block language to the website user.

Example usage

// astro.config.js
import { defineConfig } from "astro/config";
import expressiveCode from "astro-expressive-code";
import { pluginDataLang } from "expressive-code-plugin-data-lang";

export default defineConfig({
  integrations: [
    expressiveCode({
      plugins: [pluginDataLang()],
    }),
  ],
});

Example CSS for showing the psuedo-element

.expressive-code .frame::after {
  content: attr(data-lang);
  position: absolute;
  right: 1em;
  bottom: 1em;
  opacity: 0.7;
}