Trigger To Insert/Update To Another Collection

MongoDB Atlas Atlas Triggers & Functions
10

OK! I finally got it working:

I copy over the fullDocument every time… I know I know only the changed fields. But the point of this is to only run when a blog post is update, rare, so I’d rather make sure everything copied will than care about that level of efficiency?

exports = async function(changeEvent) {
  
  const post = changeEvent.fullDocument;
  if (post === undefined) { return; }
  const mdId = post._id;
  const htmlId = post.hasOwnProperty("htmlId") ? post.htmlId : undefined;
  
  // convert to html post
  delete post._id;
  delete post.htmlId;
  post.contentType = "html";
  
  const htmlCollection = context.services.get("Cluster0").db("database").collection("posts_html");
  
  if (htmlId === undefined) {
    const res = await htmlCollection.insertOne(post);
    const mdCollection = context.services.get("Cluster0").db("database").collection("posts_md");
    mdCollection.updateOne({_id: mdId}, { $set: {htmlId: res.insertedId} });
    
  } else {
    return htmlCollection.updateOne({_id: htmlId}, { $set: post}, {upsert: true});
  }
};

NEXT STEP: Get the markdown library working with a trigger… Twilio is a special third party service?

How do I add a node library for markdown?