MainActivity:
public class MainActivity extends AppCompatActivity {
private RecyclerView mRecyclerView;
private FirebaseAdapter mAdapter;
private static final String TAG = "MainActivity";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView = (RecyclerView)findViewById(R.id.recyclerview);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
FirebaseRecyclerOptions<DataClass> options =
new FirebaseRecyclerOptions.Builder<DataClass>()
.setQuery(FirebaseDatabase.getInstance().getReference().child("Users"), DataClass.class)
.build();
mAdapter = new FirebaseAdapter(options);
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL));
}
#Override
protected void onStart() {
super.onStart();
mAdapter.startListening();
}
#Override
protected void onStop() {
super.onStop();
mAdapter.stopListening();
}
}
FirebaseAdapter
public class FirebaseAdapter extends FirebaseRecyclerAdapter<DataClass,FirebaseAdapter.MyviewHolder> {
private static final String TAG = "FirebaseAdapter";
public FirebaseAdapter(#NonNull FirebaseRecyclerOptions<DataClass> options) {
super(options);
}
#Override
protected void onBindViewHolder(#NonNull MyviewHolder holder, int position, #NonNull DataClass model) {
holder.name.setText(model.getName());
holder.age.setText(model.getAge());
Log.d(TAG, "onBindViewHolder: Now Bind method executing");
}
#NonNull
#Override
public MyviewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
View v= layoutInflater.inflate(R.layout.row_represent,parent,false);
MyviewHolder v1 = new MyviewHolder(v);
Log.d(TAG, "onCreateViewHolder: Now on create method executing");
return v1;
}
public static class MyviewHolder extends RecyclerView.ViewHolder{
TextView name;
TextView age;
public MyviewHolder(#NonNull View itemView) {
super(itemView);
name = (TextView)itemView.findViewById(R.id.names);
age = (TextView) itemView.findViewById(R.id.age);
}
}
}
DataClass
public class DataClass {
private String name;
private String age;
public DataClass(){
}
public DataClass(String name, String age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public String getAge() {
return age;
}
}
doubt in this parts
public DataClass(String name, String age) {
this.name = name;
this.age = age;
}
protected void onBindViewHolder(#NonNull MyviewHolder holder, int position, #NonNull DataClass model) {
holder.name.setText(model.getName());
holder.age.setText(model.getAge());
Log.d(TAG, "onBindViewHolder: Now Bind method executing");
}
because showing me that constructor never used
I'm not getting any errors but still my screen shows empty, Actually it is displaying null data
how to find it and guys tell me how to solve this issue
I know I made small mistake somewhere in this code help me to rectify it
Thank you.............................................
Replace this code
From
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
To
RecyclerView.LayoutManager layoutManager;
layoutManager = new LinearLayoutManager(this, RecyclerView.VERTICAL, false);
mRecyclerView.setLayoutManager(layoutManager);
Hope this work.
do u have any messages in firebase database or its empty?
you can add some messages through firebase so you can check it
Related
This question already has an answer here:
Firebase Android ListView not being displayed
(1 answer)
Closed 1 year ago.
I am an android developer beginner, I am having a problem fetch files from firestore recycle view in the main activity but I can fetch files from fragments.
This is my main activity
public class FoodInfoActivity extends AppCompatActivity {
RecyclerView recyclerView1,recyclerView2;
private FirebaseFirestore db = FirebaseFirestore.getInstance();
private CollectionReference notebookRef;
private NoteAdapter adapter;
FirebaseAuth fAuth;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_food_info);
fAuth = FirebaseAuth.getInstance();
setUpRecyclerView();
}
private void setUpRecyclerView() {
notebookRef = db.collection("FoodInside");
Query query = notebookRef;
FirestoreRecyclerOptions<FoodAdapter> options = new FirestoreRecyclerOptions.Builder<FoodAdapter>()
.setQuery(query, FoodAdapter.class)
.build();
adapter = new NoteAdapter(options);
RecyclerView recyclerView = findViewById(R.id.fi);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);
}
}
This is my Note adapter where i use model class to fetch file
public class NoteAdapter extends FirestoreRecyclerAdapter<FoodAdapter, NoteAdapter.NoteHolder> {
public NoteAdapter(#NonNull FirestoreRecyclerOptions<FoodAdapter> options) {
super(options);
}
#Override
protected void onBindViewHolder(#NonNull NoteHolder holder, int position, #NonNull FoodAdapter foodAdapter) {
holder.textViewTitle.setText(foodAdapter.getRestaurant());
holder.textViewDescription.setText(foodAdapter.getItem());
holder.textViewPriority.setText(String.valueOf(foodAdapter.getPrice()));
}
#NonNull
#Override
public NoteHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.food_recycle_layout,
parent, false);
return new NoteHolder(v);
}
class NoteHolder extends RecyclerView.ViewHolder {
TextView textViewTitle;
TextView textViewDescription;
TextView textViewPriority;
public NoteHolder(View itemView) {
super(itemView);
textViewTitle = itemView.findViewById(R.id.textView95a);
textViewDescription = itemView.findViewById(R.id.textView123a);
textViewPriority = itemView.findViewById(R.id.textView124a);
}
}
}
This is my adapter class ,
public class FoodAdapter {
String Restaurant;
String Item;
String Price;
String item_id;
public FoodAdapter() {
}
public FoodAdapter(String restaurant, String item, String price,String item_id) {
Restaurant = restaurant;
Item = item;
Price = price;
this.item_id = item_id;
}
public String getRestaurant() {
return Restaurant;
}
public void setRestaurant(String restaurant) {
Restaurant = restaurant;
}
public String getItem() {
return Item;
}
public void setItem(String item) {
Item = item;
}
public String getPrice() {
return Price;
}
public void setPrice(String price) {
Price = price;
}
public String getItem_id() {
return item_id;
}
public void setItem_id(String item_id) {
this.item_id = item_id;
}
}
Why it is not working in main activity but work fragment. I am just afraid. and tired...working on the project. so need solution of this problem
#Override
protected void onStart() {
super.onStart();
adapter.startListening();
}
#Override
protected void onStop() {
super.onStop();
adapter.stopListening();
}
Add this line to main activity.
I want to retrieve data from Firebase to recyclerView through FirebaseRecyclerOptionsbut it keeps showing blanks pages,I want to display the registered Users in my App and there details in a layout,I have no idea where I have gone wrong,I have multi check on my codes and I can't see any error Please can Anyone help me here.
Here Are Code for ListAdapter,Model and ListActivity
public class ListActivity extends AppCompatActivity {
private FirebaseAuth firebaseAuth;
private DatabaseReference reference;
RecyclerView recyclerView;
ListAdapter listAdapter;
private String CurrentUserID;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
recyclerView = findViewById(R.id.children_home_list);
firebaseAuth = FirebaseAuth.getInstance();
CurrentUserID = firebaseAuth.getCurrentUser().getUid();
reference = FirebaseDatabase.getInstance().getReference().child("Children Home Details");
recyclerView.setLayoutManager(new LinearLayoutManager(this));
FirebaseRecyclerOptions<Model> options =
new FirebaseRecyclerOptions.Builder<Model>()
.setQuery(reference, Model.class)
.build();
listAdapter = new ListAdapter(options);
}
#Override
protected void onStart() {
super.onStart();
listAdapter.startListening();
}
#Override
protected void onStop() {
super.onStop();
listAdapter.stopListening();
}
public class ListAdapter extends FirebaseRecyclerAdapter<Model,ListAdapter.ListViewHolder> {
public ListAdapter(#NonNull FirebaseRecyclerOptions<Model> options) {
super(options);
}
#Override
protected void onBindViewHolder(#NonNull ListViewHolder holder, int position, #NonNull Model model) {
holder.Name.setText(model.getName());
holder.Phone.setText(model.getPhone());
holder.Location.setText(model.getLocation());
holder.Email.setText(model.getMailAddress());
//Glide.with(holder.circleImageView.getContext()).load(model.IMAGELINK()).into(holder.circleImageView);
}
#NonNull
#Override
public ListViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.singlerow,parent,false);
return new ListViewHolder(view);
}
class ListViewHolder extends RecyclerView.ViewHolder {
CircleImageView circleImageView;
TextView Name,Phone,Email,Location;
public ListViewHolder(#NonNull View itemView) {
super(itemView);
circleImageView = itemView.findViewById(R.id.img1);
Name = itemView.findViewById(R.id.HomeName);
Phone = itemView.findViewById(R.id.phoneName);
Email = itemView.findViewById(R.id.paypalAddress);
Location = itemView.findViewById(R.id.location);
}
}
}
public class Model {
String Name,Phone,Location,MailAddress;
public Model(String name, String phone, String location, String mailAddress) {
Name = name;
Phone = phone;
Location = location;
MailAddress = mailAddress;
}
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public String getPhone() {
return Phone;
}
public void setPhone(String phone) {
Phone = phone;
}
public String getLocation() {
return Location;
}
public void setLocation(String location) {
Location = location;
}
public String getMailAddress() {
return MailAddress;
}
public void setMailAddress(String mailAddress) {
MailAddress = mailAddress;
}
}
In my app I have a recyclerView with elements from a Firestore database. I want by clicking on an element in the recyclerView (which is inside a fragment) to pass the data of the element to another activity. I've tried several solutions but none seem to work and I'm stuck. Please help me.
Adapter Class
public class InfoElementAdapter extends FirestoreRecyclerAdapter<InfoElement, InfoElementAdapter.InfoElementHolder> {
String urlImg;
public InfoElementAdapter(#NonNull FirestoreRecyclerOptions<InfoElement> options) {
super(options);
}
#Override
protected void onBindViewHolder(#NonNull InfoElementHolder holder, int position, #NonNull InfoElement model) {
holder.textViewNomeRest.setText(model.getNome());
holder.textViewDescrRest.setText(model.getDescrizione());
urlImg = model.getUrlImg();
Glide.with(holder.itemView.getContext()).load(urlImg).into(holder.imageView);
}
#NonNull
#Override
public InfoElementHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item_single, parent, false );
return new InfoElementHolder(v) ;
}
class InfoElementHolder extends RecyclerView.ViewHolder {
TextView textViewNomeRest;
TextView textViewDescrRest;
ImageView imageView;
public InfoElementHolder(#NonNull View itemView) {
super(itemView);
textViewNomeRest = itemView.findViewById(R.id.txt_v_nome);
textViewDescrRest = itemView.findViewById(R.id.txt_v_descrizione);
imageView = itemView.findViewById(R.id.imageV);
}
}
}
Fragment with the recyclerView
public class RestaurantFragment extends Fragment {
private FirebaseFirestore db = FirebaseFirestore.getInstance();
private CollectionReference restaurantRef = db.collection("restaurant_db");
private InfoElementAdapter adapter;
private View view;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_restaurant, container, false);
setUpRecyclerView();
return view;
}
private void setUpRecyclerView() {
Query query = restaurantRef.orderBy("nome", Query.Direction.ASCENDING);
FirestoreRecyclerOptions<InfoElement> options = new FirestoreRecyclerOptions.Builder<InfoElement>()
.setQuery(query, InfoElement.class)
.build();
adapter = new InfoElementAdapter(options);
RecyclerView recyclerView = view.findViewById(R.id.firestore_list1);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new StaggeredGridLayoutManager(Tools.getGridSpanCount(getActivity()), StaggeredGridLayoutManager.VERTICAL));
recyclerView.addItemDecoration(new Tools.SpacingItemDecoration(Tools.getGridSpanCount(getActivity()), Tools.dpToPx(getActivity(), 4),true));
recyclerView.setAdapter(adapter);
}
#Override
public void onStart() {
super.onStart();
adapter.startListening();
}
#Override
public void onStop() {
super.onStop();
if (adapter != null) {
adapter.stopListening();
}
}
}
InfoElement Class
public class InfoElement {
private String nome;
private String descrizione;
private String urlImg;
public InfoElement() {
}
public InfoElement(String nome, String descrizione, String urlImg) {
this.nome = nome;
this.descrizione = descrizione;
this.urlImg = urlImg;
}
public void setNome(String nome) {
this.nome = nome;
}
public void setDescrizione(String descrizione) {
this.descrizione = descrizione;
}
public String getUrlImg() {
return urlImg;
}
public void setUrlImg(String urlImg) {
this.urlImg = urlImg;
}
public String getNome() {
return nome;
}
public String getDescrizione() {
return descrizione;
}
}
You can change onBindViewHolder by setting up a click listener for the ViewHolder itemView, and add your data object with putExtra, and retrieve it with getIntent().getSerializableExtra at the target activity.
#Override
protected void onBindViewHolder(#NonNull InfoElementHolder holder, int position, #NonNull InfoElement model) {
holder.textViewNomeRest.setText(model.getNome());
holder.textViewDescrRest.setText(model.getDescrizione());
urlImg = model.getUrlImg();
Glide.with(holder.itemView.getContext()).load(urlImg).into(holder.imageView);
holder.itemView.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent (v.getContext(), ActivityB.class);
intent.putExtra("MyData", myData);
startActivity(intent);
}
});
}
To retrieve the data at the target Activity
getIntent().getSerializableExtra("MyData");
sorry for my bad english
My problem: when I rotate my application, all data is lost, I am using a ViewModel, my data loads when I push the button, this is my code for test .
https://github.com/elviss116/androidMvvm-master
This is the Fragment :
public class MovieListFragment extends Fragment {
private MovieListViewModel mViewModel;
private List<MovieModel.DataModel> movieList = new ArrayList<>();
private RecyclerView recyclerView;
private MoviesAdapter mAdapter;
private Button cargar;
public static MovieListFragment newInstance() {
return new MovieListFragment();
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container,
#Nullable Bundle savedInstanceState) {
View view= inflater.inflate(R.layout.movie_list_fragment, container, false);
recyclerView = (RecyclerView)view.findViewById(R.id.recycler_view);
cargar = view.findViewById(R.id.btnCargar);
mAdapter = new MoviesAdapter(movieList);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getContext());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(mAdapter);
return view;
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
cargar.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mViewModel = ViewModelProviders.of(MovieListFragment.this).get(MovieListViewModel.class);
mViewModel.init();
mViewModel.getMovies().observe(MovieListFragment.this, new Observer<MovieModel>() {
#Override
public void onChanged(#Nullable MovieModel movieModels) {
movieList.addAll(movieModels.getData());
mAdapter.notifyDataSetChanged();
}
});
}
});
}
}
this is the ViewModel :
public class MovieModel {
#SerializedName("data")
List<DataModel> data;
public List<DataModel> getData() {
return data;
}
public void setData(List<DataModel> data) {
this.data = data;
}
public class DataModel {
#SerializedName("name")
String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
}
this is the adapter :
public class MoviesAdapter extends RecyclerView.Adapter<MoviesAdapter.MyViewHolder> {
private List<MovieModel.DataModel> moviesList;
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView name;
public MyViewHolder(View view) {
super(view);
name = (TextView) view.findViewById(R.id.name);
}
}
public MoviesAdapter(List<MovieModel.DataModel> moviesList) {
this.moviesList = moviesList;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext())
.inflate(R.layout.movie_list_row, parent, false);
return new MyViewHolder(itemView);
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
MovieModel.DataModel movie = moviesList.get(position);
holder.name.setText(movie.getName());
}
#Override
public int getItemCount() {
return moviesList.size();
}
}
When you rotate your phone the activity gets destroyed and re-created, so that is why you're seeing your data dissapear.
What I would recommend is grabbing and observing the view model when the activity is created, outside of the click listener. This way the fragment will immediately start observing the data when it is rotated, but will only be initialized when the button is clicked.
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mViewModel = ViewModelProviders.of(MovieListFragment.this).get(MovieListViewModel.class);
mViewModel.getMovies().observe(MovieListFragment.this, new Observer<MovieModel>() {
#Override
public void onChanged(#Nullable MovieModel movieModels) {
movieList.addAll(movieModels.getData());
mAdapter.notifyDataSetChanged();
}
});
cargar.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
mViewModel.init();
}
});
}
I am trying to implement OnClick in my recyclerview,but i failed miserably with all the searches how to solve this problem.
I want by clicking on my cardview to go to another activity/even better fragment with another expandable lists,but i can't even do this for now.
Any help is highly appreciated
MainActivity code
package com.oleg.firestoretest;
public static final String TAG = "FireLog";
private CollectionReference noteBookRef;
private FirebaseFirestore mFirestore;
private NoteAdapter adapter;
private RecyclerView recyclerView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mFirestore = FirebaseFirestore.getInstance();
noteBookRef = mFirestore.collection("Notebook");
setupRecyclerView();
}
private void setupRecyclerView() {
Query query = noteBookRef.orderBy("priority", Query.Direction.DESCENDING);
FirestoreRecyclerOptions<Note> options = new FirestoreRecyclerOptions.Builder<Note>()
.setQuery(query,Note.class)
.build();
adapter = new NoteAdapter(options);
recyclerView = findViewById(R.id.recycler_view);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(adapter);
}
#Override
protected void onStart() {
super.onStart();
adapter.startListening();
}
#Override
protected void onStop() {
super.onStop();
adapter.stopListening();
}
}
public Note() {
}
public Note(String title, String content, int priority) {
this.title = title;
this.content = content;
this.priority = priority;
}
public String getTitle() {
return title;
}
public String getContent() {
return content;
}
public int getPriority() {
return priority;
}
}
public class NoteAdapter extends FirestoreRecyclerAdapter<Note, NoteAdapter.NoteHolder> {
private Context mContext;
public NoteAdapter(#NonNull FirestoreRecyclerOptions<Note> options) {
super(options);
}
#Override
protected void onBindViewHolder(#NonNull NoteHolder noteHolder, int i, #NonNull Note note) {
noteHolder.title.setText(note.getTitle());
noteHolder.content.setText(note.getContent());
noteHolder.priority.setText(String.valueOf(note.getPriority()));
}
#NonNull
#Override
public NoteHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.note_item,
parent, false);
return new NoteHolder(v);
}
class NoteHolder extends RecyclerView.ViewHolder {
TextView title;
TextView content;
TextView priority;
public NoteHolder(#NonNull View itemView) {
super(itemView);
title = itemView.findViewById(R.id.title_text);
content = itemView.findViewById(R.id.content_text);
priority = itemView.findViewById(R.id.priority_text);
}
}
}
Here the Code u need:
class NoteHolder extends RecyclerView.ViewHolder {
TextView title;
TextView content;
TextView priority;
CardView cardView;
public NoteHolder(#NonNull View itemView) {
super(itemView);
title = itemView.findViewById(R.id.title_text);
content = itemView.findViewById(R.id.content_text);
priority = itemView.findViewById(R.id.priority_text);
cardView = itemView.findViewById(R.id.cardView);
}
private void bind(){
cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(FirstActivity.this, SecoundActivity.class);
startActivity(intent);
}
});
}
}
Fixed it with this code!!!
public NoteHolder(#NonNull final View itemView) {
super(itemView);
cardView = itemView.findViewById(R.id.cardview);
title = itemView.findViewById(R.id.title_text);
content = itemView.findViewById(R.id.content_text);
priority = itemView.findViewById(R.id.priority_text);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
itemView.getContext().startActivity(new Intent(itemView.getContext(),Empty.class));
}
});
}