Develop Reference

About opening a new activity in respond to a click on a RecyclerView item which is inside of a fragment

I'm loading some data into a RecyclerView from Firebase Realtime Database. This RecyclerView is in a fragment and I want to open a new activity when an item is clicked. But when i add the onClickListener to an item from the adapter, my click doesn't even recognized by the app. I'm not sure what I'm doing wrong here because this method worked fine for a RecyclerView when it is inside of a normal activity.
This is a project for my university and I should submit it tomorrow. So I can really use some help.
This is the my data Adapter class,
public class Adapter_NoLimit extends RecyclerView.Adapter<Adapter_NoLimit.LViewHolder> {
Context context;
ArrayList<Helper> list_nl;
public Adapter_NoLimit(Context context, ArrayList<Helper> list_nl) {
this.context = context;
this.list_nl = list_nl;
}
#NonNull
#Override
public Adapter_NoLimit.LViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(context).inflate(R.layout.itemlist, parent, false);
return new LViewHolder(v);
}
#Override
public void onBindViewHolder(#NonNull Adapter_NoLimit.LViewHolder holder, int position) {
//final Helper temp = list_nl.get(position);
String fname_txt = list_nl.get(position).getFname();
String catg_txt = list_nl.get(position).getSpin();
String prof_img = list_nl.get(position).getProfile_url();
holder.setUsers(fname_txt, catg_txt, prof_img);
holder.f_name.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
AppCompatActivity activity = (AppCompatActivity) v.getContext();
Intent i = new Intent(activity, UserProfile_VV.class);
i.putExtra("full name", fname_txt);
activity.startActivity(i);
}
});
}
#Override
public int getItemCount() {
return list_nl.size();
}
public class LViewHolder extends RecyclerView.ViewHolder{
private TextView f_name, catG;
private ImageView profile_pic;
public LViewHolder(#NonNull View itemView) {
super(itemView);
f_name = itemView.findViewById(R.id.username_view);
catG = itemView.findViewById(R.id.category_view);
profile_pic = itemView.findViewById(R.id.userimage);
}
public void setUsers(String fname_txt, String catg_txt, String prof_img) {
f_name.setText(fname_txt);
catG.setText(catg_txt);
Picasso.get().load(prof_img).fit().into(profile_pic);
}
}
}
This is one of fragments,
public class Beauty_Frag extends Fragment {
RecyclerView recyclerView;
DatabaseReference reference, user_ref;
ArrayList<Helper> list;
Adapter adapter;
FirebaseAuth auth;
String uid;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_beauty, container, false);
recyclerView = v.findViewById(R.id.beauty_recycler_frag);
reference = FirebaseDatabase.getInstance().getReference();
user_ref = reference.child("users");
auth = FirebaseAuth.getInstance();
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
//searchField = findViewById(R.id.search_field);
list = new ArrayList<>();
adapter = new Adapter(getContext(), list);
recyclerView.setAdapter(adapter);
user_ref.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull /*#org.jetbrains.annotations.NotNull*/ DataSnapshot snapshot) {
for (DataSnapshot key : snapshot.getChildren()) {
if( key.child("spin").getValue().toString().equals("Beauty")) {
Helper helper = key.getValue(Helper.class);
list.add(helper);
adapter.notifyDataSetChanged();
}
}
}
#Override
public void onCancelled(#NonNull /*#org.jetbrains.annotations.NotNull*/ DatabaseError error) {
}
});
return v;
}
}
You are very welcome if you have any solution.

Use below code for onClicklistner:
holder.f_name.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(context, UserProfile_VV.class);
i.putExtra("full name", fname_txt);
context.startActivity(i);
}
});

android recylerview not displaying firebase data

I am trying to retrieve data from another firebase project, but the data is not displaying in the recylerview. I am not getting any errors but just a blank cardview. Can someone help me solve this issue that I am having. My code is below.
// This my code
public class ExampleFragment extends Fragment {
LinearLayout linearLayoutWithoutItems,linearLayoutNoConnection;
View rootView;
private RecyclerView recyclerView;
private Adapter1 aAdapter;
ImageButton menu_click;
ImageView imageView;
//Variables
NavigationView navigationView;
Toolbar toolbar;
Menu menu;
LinearLayout linearLayout;
TextView textView;
BottomNavigationView bottomNavigationView;
private DatabaseReference databaseReference;
private ArrayList<Model_Information> myUploads;
FirebaseStorage firebaseStorage;
StorageReference storageReference;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView =inflater.inflate(R.layout.fragment_example, container, false);
init();
return rootView;
}
public void init()
{
recyclerView = rootView.findViewById(R.id.WithItems_recyclerview);
linearLayoutWithoutItems = rootView.findViewById(R.id.WithoutItems);
linearLayoutNoConnection = rootView.findViewById(R.id.no_connection);
RecyclerView.LayoutManager layoutManager = new GridLayoutManager(getContext(),1);
recyclerView.setLayoutManager(layoutManager);
myUploads = new ArrayList<Model_Information>();
aAdapter = new Adapter1(getContext(), myUploads);
recyclerView.setAdapter(aAdapter);
aAdapter.notifyDataSetChanged();
databaseReference = FirebaseDatabase.getInstance("https://liou-43081.firebaseio.com").getReference().child("Post");
if (InternetConnection.checkConnection(getContext())) {
databaseReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
if(dataSnapshot.exists()){
//progressBar.setVisibility(View.GONE);
for (DataSnapshot postsnapshot : dataSnapshot.getChildren()) {
Model_Information upload=postsnapshot.getValue(Model_Information.class);
//myUploads.clear();
myUploads.add(upload);
aAdapter = new Adapter1(getContext(), myUploads);
recyclerView.setAdapter(aAdapter);
aAdapter.notifyDataSetChanged();
recyclerView.invalidate();
}
linearLayoutWithoutItems.setVisibility(View.GONE);
recyclerView.setVisibility(View.VISIBLE);
aAdapter.notifyDataSetChanged();
}else{
linearLayoutWithoutItems.setVisibility(View.VISIBLE);
recyclerView.setVisibility(View.GONE);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Toast.makeText(getContext(), databaseError.getMessage(), Toast.LENGTH_LONG).show();
}
});
} else {
linearLayoutNoConnection.setVisibility(View.VISIBLE);
linearLayoutWithoutItems.setVisibility(View.GONE);
recyclerView.setVisibility(View.GONE);
}
//Adapter1.class
public class Adapter1 extends RecyclerView.Adapter<Adapter1.ImageViewHolder>{
private Context mContext;
private ArrayList<Model_Information> users;
DatabaseReference databaseReference;
public Adapter1(Context context, ArrayList<Model_Information> uploads){
mContext = context;
users = uploads;
}
#NonNull
#Override
public ImageViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View V = LayoutInflater.from(mContext).inflate(R.layout.cardview1, parent, false);
return new ImageViewHolder(V);
}
#Override
public void onBindViewHolder(#NonNull final ImageViewHolder holder, final int position) {
//String uploadCurrent=users.get(position).getmImageUrl();
Glide.with(mContext).load(users.get(position).getmImageUrl()).thumbnail(0.05f).transition(DrawableTransitionOptions.withCrossFade()).fitCenter().centerInside().into(holder.imageView);
holder.imageView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//Toast.makeText(mContext,users.get(position).getCategory(), Toast.LENGTH_LONG).show();
Long l= Long.valueOf(1);
databaseReference = FirebaseDatabase.getInstance("https://louie-43081.firebaseio.com").getReference("Clicks_and_Views").child(users.get(position).id);
databaseReference.child("views").setValue(ServerValue.increment(l));
/*
Intent intent=new Intent(mContext,ViewActivity.class);
intent.putExtra("website",users.get(position).getWebsiteurl());
intent.putExtra("action",users.get(position).getAction());
intent.putExtra("image",users.get(position).getmImageUrl());
intent.putExtra("id",users.get(position).id);
mContext.startActivity(intent);
*/
}
});
}
#Override
public int getItemCount() {
return users.size();
}
public class ImageViewHolder extends RecyclerView.ViewHolder{
public ImageView imageView;
public ImageViewHolder(#NonNull View itemView) {
super(itemView);
imageView=itemView.findViewById(R.id.image);
}
}

You should not initialize adapter twice.
Your code block should look like this,
for (DataSnapshot postsnapshot : dataSnapshot.getChildren()) {
Model_Information upload=postsnapshot.getValue(Model_Information.class);
myUploads.add(upload);
aAdapter.notifyDataSetChanged();
recyclerView.invalidate();
}

Getting data from firebase but not showing in recyclerview

I am new in android development. I am trying to create list of firebase data. so i have created a recyclerview and represent the data in recyclerview.
I have featched data from firebase and assign to adapter class. but data is not showing in recyclerview.
Fragment Class
public class HomeFragment extends Fragment {
DatabaseReference reference;
RecyclerView recyclerView;
ArrayList<Carmodel> list = new ArrayList<>();;
CarAdapter adapter;
public View onCreateView(#NonNull LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.recyclerview, container, false);
recyclerView = (RecyclerView) root.findViewById(R.id.recycler);
recyclerView.setLayoutManager( new LinearLayoutManager(getContext()));
reference = FirebaseDatabase.getInstance().getReference().child("AddCar");
reference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
Carmodel p = dataSnapshot1.getValue(Carmodel.class);
Log.e("Get Data", p.getCarName());
list.add(p);
}
}
#Override
public void onCancelled(#NonNull DatabaseError error) {
Toast.makeText(getActivity(), "Opsss.... Something is wrong", Toast.LENGTH_SHORT).show();
}
});
adapter = new CarAdapter(getContext(), list);
recyclerView.setAdapter(adapter);
adapter.notifyDataSetChanged();
return root;
}
}
Adapert Class
public class CarAdapter extends RecyclerView.Adapter<CarAdapter.MyViewHolder> {
Context context;
ArrayList<Carmodel> profiles;
public CarAdapter(Context c , ArrayList<Carmodel> p)
{
context = c;
profiles = p;
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
return new MyViewHolder(LayoutInflater.from(context).inflate(R.layout.fragment_admin_home, parent, false));
}
#Override
public void onBindViewHolder(#NonNull MyViewHolder holder, int position) {
holder.name.setText(profiles.get(position).getCarName());
holder.seater.setText(profiles.get(position).getSeater());
holder.price.setText(profiles.get(position).getPrice());
holder.status.setText(profiles.get(position).getAvailable());
Picasso.get().load(profiles.get(position).getImageURL()).into(holder.car_image);
}
#Override
public int getItemCount() {
return profiles.size();
}
public class MyViewHolder extends RecyclerView.ViewHolder
{
TextView name,seater,price, status;
ImageView car_image;
#SuppressLint("CutPasteId")
public MyViewHolder(View itemView) {
super(itemView);
name = (TextView) itemView.findViewById(R.id.CarName);
seater = (TextView) itemView.findViewById(R.id.Seater);
price = (TextView) itemView.findViewById(R.id.Seater);
car_image = (ImageView) itemView.findViewById(R.id.imageView);
status = (TextView) itemView.findViewById(R.id.Status);
}
}

Carmodel p = dataSnapshot1.getValue(Carmodel.class);
make you sure it is (p) not empty

You are notifying your adapter in wrong time for data change
adapter = new CarAdapter(getContext(), list);
recyclerView.setAdapter(adapter);
reference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
Carmodel p = dataSnapshot1.getValue(Carmodel.class);
Log.e("Get Data", p.getCarName());
list.add(p);
}
adapter.notifyDataSetChanged();
}
#Override
public void onCancelled(#NonNull DatabaseError error) {
Toast.makeText(getActivity(), "Opsss.... Something is wrong", Toast.LENGTH_SHORT).show();
}
});
Please modify your method like this

RecycerView always reset back to first position after inserting new Firebase data

My recyclerview always reset to first position after new data is inserted to firebase. In my TestAdapter class, I have an onClickListener which increments like on a post when clicked. Whenever I click on this "like" button, view is reset to first position. I believe this issue is related to setAdapter() being called on data changed. Please help!
MainActivity fetches "post" data from Firebase and populates it in TestAdapter class.
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private TestAdapter testAdapter;
private ArrayList<Post> postList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
fetchPostFromDB();
}
private void fetchPostFromDB() {
DatabaseReference databaseRef = FirebaseDatabase.getInstance().getReference("Post");
databaseRef.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot snapshot) {
postList = new ArrayList<>();
for (DataSnapshot snap : snapshot.getChildren()) {
String post = snap.child("post").getValue().toString();
Post post = new Post(post);
postList.add(post);
}
testAdapter = new TestAdapter(getApplicationContext(), postList);
recyclerView.setAdapter(testAdapter);
}
#Override
public void onCancelled(#NonNull DatabaseError error) {
}
});
}
TestAdapter binds the data (postList) and has an onClickListener.
public class TestAdapter extends RecyclerView.Adapter<TestAdapter.TestHolder> {
private List<Post> postList;
private Context context;
private DatabaseReference databaseReference;
public TestAdapter(Context ct, ArrayList<Post> postList) {
context = ct;
this.postList = postList;
}
#NonNull
#Override
public TestHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(context);
View view = layoutInflater.inflate(R.layout.post_item, parent, false);
final TestHolder holder = new TestHolder(view);
holder.ibLike.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String postID = postList.get(holder.getAdapterPosition()).getPostID();
databaseReference = FirebaseDatabase.getInstance().getReference("Posts").child(postID).child("likes");
int incrementLike = postList.get(holder.getAdapterPosition()).getLikes() + 1;
databaseReference.setValue(incrementLike);
}
});
return holder;
}
#Override
public void onBindViewHolder(#NonNull final TestHolder holder, final int position) {
holder.tvPost.setText(postList.get(position).getPost());
holder.tvVotes.setText(Integer.toString(postList.get(position).getLikes()));
}
#Override
public int getItemCount() {
return postList.size();
}
public static class TestHolder extends RecyclerView.ViewHolder {
TextView tvPost, tvLikes;
ImageButton ibLike;
public TestHolder(#NonNull View itemView) {
super(itemView);
tvPost = itemView.findViewById(R.id.tvPost);
tvLikes = itemView.findViewById(R.id.tvLikes);
ibLike = itemView.findViewById(R.id.ibLike);
}
}

Here need to initialize your adapter class from main activity. and then when data received just call adapter.notifiyDatasetChanged like:
onCreate():
postList = new ArrayList<>();
recyclerView = findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
testAdapter = new TestAdapter(getApplicationContext(), postList);
recyclerView.setAdapter(testAdapter);
and from your fetchPostFromDB delete adapter initialization insted of this just put this line testAdapter.notifiyDataSetChanged()
And when click on text button you can update/handle like this:
holder.ibLike.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String postID = postList.get(holder.getAdapterPosition()).getPostID();
databaseReference = FirebaseDatabase.getInstance().getReference("Posts").child(postID).child("likes");
int incrementLike = postList.get(holder.getAdapterPosition()).getLikes() + 1;
postList.get(holder.getAdapterPosition()).setLikes(incrementLike);
databaseReference.setValue(incrementLike);
notifyDataSetChanged();
}
});

RecyclerView In Fragment Not Working (Unable to add data to it)

Here is my fragment
public class TransactionsFragment extends Fragment {
private FirebaseAuth mAuth;
private DatabaseReference mDBref;
FirebaseUser Fuser;
private String UID;
private RecyclerView recyclerView;
private RecyclerView.Adapter trpAdapter;
private List<TransGetterSetter> DataList;
String trans_id;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_transactions, container, false);
DataList = new ArrayList<>();
recyclerView = (RecyclerView) v.findViewById(R.id.RVList);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
TransactionRVAdapter trvAdapter = new TransactionRVAdapter(DataList, getContext());
recyclerView.setAdapter(trvAdapter);
mAuth = FirebaseAuth.getInstance();
mDBref = FirebaseDatabase.getInstance().getReference();
Fuser = mAuth.getInstance().getCurrentUser();
UID = Fuser.getUid();
mDBref.child("transactions").child(UID).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot chidSnap : dataSnapshot.getChildren()) {
trans_id = chidSnap.getKey();
DataList.add(new TransGetterSetter("" + trans_id));
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
trvAdapter.notifyDataSetChanged();
return v;
}
}
If i toast "trans_id" string im getting expected result.
Here is My Adapter class
public class TransactionRVAdapter extends RecyclerView.Adapter<TransactionRVAdapter.rvViewHolder> {
Context mContext;
List<TransGetterSetter> DataList = new ArrayList<>();
public class rvViewHolder extends RecyclerView.ViewHolder{
private TextView TransId;
public rvViewHolder(#NonNull View itemView) {
super(itemView);
TransId = (TextView) itemView.findViewById(R.id.TransIdTxt);
}
}
public TransactionRVAdapter( List<TransGetterSetter> DataList,Context mContext){
this.DataList = DataList;
this.mContext = mContext;
}
#NonNull
#Override
public rvViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
LayoutInflater inflater = LayoutInflater.from(mContext);
View view = inflater.inflate(R.layout.fragment_transactions_item, viewGroup, false);
return new rvViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull rvViewHolder rvViewHolder, int i) {
rvViewHolder.TransId.setText(DataList.get(i).getTrans_id());
}
#Override
public int getItemCount() {
return DataList.size();
}
}
Here is my GetterSetter class
public class TransGetterSetter {
private String trans_id;
public TransGetterSetter() {
}
public TransGetterSetter(String trans_id) {
this.trans_id = trans_id;
}
public String getTrans_id() {
return trans_id;
}
public void setTrans_id(String trans_id) {
this.trans_id = trans_id;
}
}
Im able to get Data from firebase, but when i try to add it to recycler view it dosen't show any data. Recycler view is showing empty. I checked my code many time but haven't found solution.

You should call :
trvAdapter.notifyDataSetChanged();
After the for loop inside the (onDataChange) event listener.

Try to called ..
DataList.add(new TransGetterSetter("" + trans_id));
after this line called ..
trvAdapter.notifyDataSetChanged();