CODE EXAMPLE FOR JAVASCRIPT

Display all posts from database

useEffect(() => {
    const getPostData = async () => {
      const q = collection(db, "posts");
      const docSnap = await getDocs(q);
      const promises = docSnap.docs.map(async (item) => {
        const tmp = collection(db, "posts", item.id, "userPosts");
        const tmpSnap = await getDocs(tmp);
        return tmpSnap.docs.map((element) => element.data());
      });
      const arrayOfPosts = await Promise.all(promises);
      let newPosts = [];
      arrayOfPosts.forEach((posts) => {
        newPosts = [...newPosts, ...posts];
      });
      setPosts(newPosts);
    };

    getPostData().catch(console.error);
    return;
  }, []);