Adding a "last edited" timestamp?

[alexgleason]

Hi, I'm really enjoying using contentlayer! I've built a blog with Next.js and I'm planning to build documentation with it too.

Like some documentation websites, I'd like to add a "last edited" timestamp as well as a link to the page source on GitLab.

My current idea is to add it to computedFields under Post, and try to do git stuff in there to get the timestamp. Is this a sensible approach, or any other ideas?

[spcbfr]

I am also interested in this

[nkilm]

That would be nice! I'll be happy to help.

[alexgleason]

Hey guys, I figured it out.

See: contentlayer.config.js

    lastModified: {
      type: 'string',
      resolve: (post) => getFileInfo(`_blog/${post._raw.sourceFilePath}`).lastModified,
    },
    sourceUrl: {
      type: 'string',
      resolve: (post) => getFileInfo(`_blog/${post._raw.sourceFilePath}`).sourceUrl,
    },

files.ts:

import { getLastModified } from './git';

interface FileInfo {
  lastModified: string
  sourceUrl: string
}

const getFileInfo = (filename: string): FileInfo => {
  return {
    lastModified: getLastModified(filename),
    sourceUrl: `https://gitlab.com/soapbox-pub/soapbox.pub/-/blob/main/${filename}`,
  };
};

export {
  getFileInfo,
};

git.ts:

import { execFileSync } from 'child_process';

const getLastModified = (filename: string): string => {
  const raw = execFileSync('git', ['log', '-1', '--pretty=%cI', filename]);
  return String(raw).trim();
};

export {
  getLastModified,
};

Finally, blog/[slug].tsx:

                {post.lastModified && (
                  <p className='text-gray-500 mt-12'>
                    Last edited <a className='text-azure' href={post.sourceUrl} target='_blank'>
                      <DateFormatter dateString={post.lastModified} />
                    </a>.
                  </p>
                )}