import {isDarkTheme} from '../utils.ts';
import {makeCodeCopyButton} from './codecopy.ts';
import {displayError} from './common.ts';
const {mermaidMaxSourceCharacters} = window.config;
// margin removal is for https://github.com/mermaid-js/mermaid/issues/4907
const iframeCss = `:root {color-scheme: normal}
body {margin: 0; padding: 0; overflow: hidden}
#mermaid {display: block; margin: 0 auto}
blockquote, dd, dl, figure, h1, h2, h3, h4, h5, h6, hr, p, pre {margin: 0}`;
export async function initMarkupCodeMermaid(elMarkup: HTMLElement): Promise<void> {
const el = elMarkup.querySelector('code.language-mermaid'); // .markup code.language-mermaid
if (!el) return;
const {default: mermaid} = await import(/* webpackChunkName: "mermaid" */'mermaid');
mermaid.initialize({
startOnLoad: false,
theme: isDarkTheme() ? 'dark' : 'neutral',
securityLevel: 'strict',
suppressErrorRendering: true,
});
const pre = el.closest('pre');
if (pre.hasAttribute('data-render-done')) return;
const source = el.textContent;
if (mermaidMaxSourceCharacters >= 0 && source.length > mermaidMaxSourceCharacters) {
displayError(pre, new Error(`Mermaid source of ${source.length} characters exceeds the maximum allowed length of ${mermaidMaxSourceCharacters}.`));
return;
}
try {
await mermaid.parse(source);
} catch (err) {
displayError(pre, err);
return;
}
try {
// can't use bindFunctions here because we can't cross the iframe boundary. This
// means js-based interactions won't work but they aren't intended to work either
const {svg} = await mermaid.render('mermaid', source);
const iframe = document.createElement('iframe');
iframe.classList.add('markup-content-iframe', 'tw-invisible');
iframe.srcdoc = `<html><head><style>${iframeCss}</style></head><body>${svg}</body></html>`;
const mermaidBlock = document.createElement('div');
mermaidBlock.classList.add('mermaid-block', 'is-loading', 'tw-hidden');
mermaidBlock.append(iframe);
const btn = makeCodeCopyButton();
btn.setAttribute('data-clipboard-text', source);
mermaidBlock.append(btn);
const updateIframeHeight = () => {
const body = iframe.contentWindow?.document?.body;
if (body) {
iframe.style.height = `${body.clientHeight}px`;
}
};
iframe.addEventListener('load', () => {
pre.replaceWith(mermaidBlock);
mermaidBlock.classList.remove('tw-hidden');
updateIframeHeight();
setTimeout(() => { // avoid flash of iframe background
mermaidBlock.classList.remove('is-loading');
iframe.classList.remove('tw-invisible');
}, 0);
// update height when element's visibility state changes, for example when the diagram is inside
// a <details> + <summary> block and the <details> block becomes visible upon user interaction, it
// would initially set a incorrect height and the correct height is set during this callback.
(new IntersectionObserver(() => {
updateIframeHeight();
}, {root: document.documentElement})).observe(iframe);
});
document.body.append(mermaidBlock);
} catch (err) {
displayError(pre, err);
}
}