eleventy.config.markdown.js

import container from 'markdown-it-container'

// Custom Callout Blocks Plugin For Markdown-it
// equk.co.uk

export default (md) => {
  md.use(...createContainer('tip', 'Tip', md))
    .use(...createContainer('info', 'Info', md))
    .use(...createContainer('warning', 'Warning', md))
    .use(...createContainer('danger', 'Danger', md))
    .use(...createContainer('note', 'Note', md))
    .use(...createContainer('important', 'Important', md))
}

function createContainer(conClass, defaultTitle, md) {
  return [
    container,
    conClass,
    {
      render(tokens, idx) {
        const token = tokens[idx]
        const info = token.info.trim().slice(conClass.length).trim()
        const attrs = md.renderer.renderAttrs(token)
        if (token.nesting === 1) {
          const title = md.renderInline(info || defaultTitle)
          return `<div class="${conClass} callout-block"${attrs}><p class="callout-block-title">${title}</p>\n`
        } else return `</div>\n`
      },
    },
  ]
}