I'm trying to make a comment system for posts on my social media app. In my database each post has a section inside of "comments" table, like so:
"hypno--######" is the title of the social media post. It Contains the comment, user id of the user who posted the comment, and a unixtimestamp when the comment was posted. Each comment is titled after the time it was posted.
This is the Comment class
public class comment {
public String uID;
public String comment_t;
public long unixTimestamp;
public comment() {
// Default constructor required for calls to DataSnapshot.getValue(User.class)
}
public comment(String uID, String comment_t, long unixTimestamp) {
this.uID = uID;
this.comment_t = comment_t;
this.unixTimestamp = unixTimestamp;
}
public String getuID() {
return uID;
}
public void setuID(String uID) {
this.uID = uID;
}
public String getComment() {return comment_t;}
public void setComment() {this.comment_t = comment_t; }
public long getUnixTimestamp() {
return unixTimestamp;
}
}
This is the Comment Adapter:
Public class Adapter_Comment extends FirebaseRecyclerAdapter<comment, Adapter_Comment.ViewHolder_com> {
private DatabaseReference mDatabase;
private static final String TAG = "RecyclerViewAdapter";
private Context mContext;
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
private static AppCompatActivity unwrap(Context context) {
while (!(context instanceof Activity) && context instanceof ContextWrapper) {
context = ((ContextWrapper) context).getBaseContext();
}
return (AppCompatActivity) context;
}
public Adapter_Comment(@NonNull FirebaseRecyclerOptions<comment> options) {
super(options);
//this.mContext = mContext;
}
@NonNull
@Override
public ViewHolder_com onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_comment, parent, false);
mDatabase = FirebaseDatabase.getInstance().getReference();
return new ViewHolder_com(view);
}
@Override
protected void onBindViewHolder(@NonNull ViewHolder_com holder, int position, @NonNull comment model) {
mDatabase = FirebaseDatabase.getInstance().getReference();
long dv = model.getUnixTimestamp()*-1000;
Date df = new java.util.Date(dv);
String vv = new SimpleDateFormat("MM dd, yyyy hh:mma", Locale.ENGLISH).format(df);
holder.time.setText(vv);
String com = model.getComment();
holder.comment_text.setText(com);
mDatabase.child("users").child(model.getuID()).child("profileUrl").addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
if (snapshot.exists())
{
final String picUrl = snapshot.getValue(String.class);
Glide.with(holder.postPfp.getContext()).load(picUrl).into(holder.postPfp);
}
}
@Override
public void onCancelled(@NonNull DatabaseError error) { }
});
holder.postPfp.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//AppCompatActivity activity = (AppCompatActivity) v.getContext();
AppCompatActivity activity = unwrap(v.getContext());
Fragment OtherProfileFragment = new OtherProfileFragment();
Bundle bundle = new Bundle();
bundle.putString("key", model.getuID());
OtherProfileFragment.setArguments(bundle);
activity.getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, OtherProfileFragment).addToBackStack(null).commit();
}
});
}
public class ViewHolder_com extends RecyclerView.ViewHolder {
TextView comment_text;
CircleImageView postPfp;
TextView time;
RelativeLayout comment_layout;
public ViewHolder_com(@NonNull View itemView) {
super(itemView);
postPfp = itemView.findViewById(R.id.iv_comment_icon);
comment_text = itemView.findViewById(R.id.tv_comment_text);
time = itemView.findViewById(R.id.tv_comment_time);
comment_layout = itemView.findViewById(R.id.comment_layout);
}
}
}
This is Comment Fragment:
public class CommentFragment extends Fragment {
private DatabaseReference mDatabase;
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
View view;
String value;
RecyclerView recyclerView;
Query query;
TextView comment_text;
long unixTime = System.currentTimeMillis() / 1000L;
public long globalUnix;
Button comment_post;
String comment_string;
Adapter_Comment adapter;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_comment, container, false);
value = getArguments().getString("key");
mDatabase = FirebaseDatabase.getInstance().getReference();
recyclerView = view.findViewById(R.id.recyclerv_comment);
comment_text = view.findViewById(R.id.tv_comment_type);
comment_post = view.findViewById(R.id.btn_comment_post);
globalUnix = (unixTime * -1);
comment_post.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(comment_text.getText().toString() == NULL){
Toast.makeText(getActivity(), "No Comment Typed", Toast.LENGTH_LONG).show();
}
else{
comment com = new comment();
com.uID = user.getUid();
com.comment_t = comment_text.getText().toString();
com.unixTimestamp = globalUnix;
mDatabase.child("comments").child(value).child(globalUnix "").setValue(com);
}
}
});
initRecyclerView();
return view;
}
private void initRecyclerView(){
//Log.d(TAG, "initRecyclerView: init recyclerView");
LinearLayoutManager layoutManager = new LinearLayoutManager(getContext());
recyclerView.setLayoutManager(layoutManager);
query = FirebaseDatabase.getInstance().getReference().child("comments").orderByValue();
FirebaseRecyclerOptions<comment> options = new FirebaseRecyclerOptions.Builder<comment>().setQuery(query, comment.class).build();
adapter = new Adapter_Comment(options);
recyclerView.setAdapter(adapter);
adapter.startListening();
adapter.notifyDataSetChanged();
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
}
Inside of the adapter I'm using the comment model, to get the uID, comment and timestamp to fill the holder, however when i set these values im getting null values. Is there something im missing when trying to connect the adapter/firebase and model/holder?
long dv = model.getUnixTimestamp()*-1000;
Date df = new java.util.Date(dv);
String vv = new SimpleDateFormat("MM dd, yyyy hh:mma", Locale.ENGLISH).format(df);
holder.time.setText(vv);
String com = model.getComment();
holder.comment_text.setText(com);
mDatabase.child("users").child(model.getuID()).child("profileUrl").addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
if (snapshot.exists())
{
final String picUrl = snapshot.getValue(String.class);
Glide.with(holder.postPfp.getContext()).load(picUrl).into(holder.postPfp);
}
}
@Override
public void onCancelled(@NonNull DatabaseError error) { }
});
CodePudding user response：
There's really too much going on in here, but...
As far as I can see you're creating a FirebaseUI adapter on FirebaseDatabase.getInstance().getReference().child("comments"). FirebaseUI adapters show the direct child nodes of the node you pass in, so in your case it'll create one view for the hypno---...196 node. You're trying to read a Comment object from there, but don't exist until one level lower in your JSON.
So you can:
- Either show the comments for one post, by basing the adapter off of that. So:
FirebaseDatabase.getInstance().getReference().child("comments").child("hypno---...196")(which the real key in there). - Or you can show one piece of information about each post, for example its key.
If you want to show a flat list of comments for all posts through the FirebaseUI adapter, you'll have to store a flat list of comments across all posts in your database too.