rtdb_social_star_transaction.js

// This snippet file was generated by processing the source file:
// ./database-next/read-and-write.js
//
// To update the snippets in this file, edit the source and then run
// 'npm run snippets'.

// [START rtdb_social_star_transaction_modular]
import { getDatabase, ref, runTransaction } from "firebase/database";

function toggleStar(uid) {
  const db = getDatabase();
  const postRef = ref(db, '/posts/foo-bar-123');

  runTransaction(postRef, (post) => {
    if (post) {
      if (post.stars && post.stars[uid]) {
        post.starCount--;
        post.stars[uid] = null;
      } else {
        post.starCount++;
        if (!post.stars) {
          post.stars = {};
        }
        post.stars[uid] = true;
      }
    }
    return post;
  });
}
// [END rtdb_social_star_transaction_modular]