从两个不同的 Firebase 节点检索和设置 RecyclerView 数据

Question

我的主要目标是根据用户之前的操作将 RecyclerView 项目设置为 "favorited"。我可以在点击时存储和删除这些数据，但我很难在正确的时间在正确的地方显示它。

我正在使用两个不同的节点来实现这一点：

"quotes" : {
   "0" : {
      "Name" : "Foo",
      "Source" : "Bar" },
   "1" : {
      "Name" : "Foo",
      "Source" : "Bar" },
   "2" : {
      "Name" : "Foo",
      "Source" : "Bar" }
   },

"favorites" : {
   "blah@blah,com" : {
      "uid0" : "0"
      "uid1" : "2" }}}

基本上我想做的是：在 RecyclerView 中显示所有报价，如果它们的 ID 显示在该唯一用户的收藏夹中，则将其可视化设置为收藏夹。我在此处包含了一些似乎对我不起作用的代码。

private void bindHeart(final ItemHeartCardBinding binding) {
        if (inProgress) {
            animateProgress(binding);
        } else {
            binding.favorite.setImageResource(R.drawable.favorite_state_list);
        }
        //Loop through users favorites to see if current item exists
        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        DatabaseReference mRootRef = FirebaseDatabase.getInstance().getReference();
        String email = "";
        if (user != null) {
            email = user.getEmail();
            email = email.replace(".", ",");
        }

        final DatabaseReference favoriteRef = mRootRef.child("favorites/" + email);

        //quoteKeyStringResId is passed in here as each RecyclerView item is being created. It's the uid of each quote.
        final Query queryRef = favoriteRef.orderByValue().startAt(quoteKeyStringResId).endAt(quoteKeyStringResId);

        queryRef.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {

                if (dataSnapshot.getValue().toString().equals(quoteKeyStringResId)) {
                    binding.favorite.setChecked(checked);
                } else {
                    binding.favorite.setChecked(!checked);
                }
}

Answer 1

我仔细研究了 Firebase database samples 并找到了一种更好的数据建模方法。在同一节点中包含所有相关数据允许我同时查询所有数据，而不必担心保持 RecyclerView 项目的顺序相同。事情并没有这么浅薄，但我认为没关系：

"quotes" : {
   "0" : {
      "Name" : "Foo",
      "Source" : "Bar",
      //Moved this from a separate node into here
      "Favorites" : {
          //Each user will be listed if favorited, and removed if unfavorited, making it easy to track and get totals
          "userUid" : "true",
          "userUid4" : "true" }},
   "1" : {
      "Name" : "Foo",
      "Source" : "Bar" },
   "2" : {
      "Name" : "Foo",
      "Source" : "Bar",
      "Favorites" : {
          "userUid" : "true" }
   }}

从两个不同的 Firebase 节点检索和设置 RecyclerView 数据

Retrieve and set RecyclerView data from two different Firebase nodes

android

android-recyclerview

firebase-realtime-database

android-databinding