How to pass document id of Firestore document through OnclickListener?

Question

I want to add onClickListener to items in the recyclerview showing data from firestore. OnClick should pass the corresponding document id through intent . Pleas help

• ProductFragment showing the data

   public class ProductFragment extends Fragment {
  
      private static final String TAG = "ProductFragment";
      private FirebaseFirestore firestoreDB;
  private RecyclerView productRecyclerView;
  
  
  public ProductFragment() {
      // Required empty public constructor
  }
  
  
  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container,
                           Bundle savedInstanceState) {
      // Inflate the layout for this fragment
  
      View view =  inflater.inflate(R.layout.fragment_product, container, false);
      firestoreDB = FirebaseFirestore.getInstance();
      productRecyclerView = (RecyclerView) view.findViewById(R.id.Product_RecyclerView);
  
      LinearLayoutManager recyclerLayoutManager = new LinearLayoutManager(getActivity().getApplicationContext());
      productRecyclerView.setLayoutManager(recyclerLayoutManager);
  
      DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(productRecyclerView.getContext(),
                                                                  recyclerLayoutManager.getOrientation());
      productRecyclerView.addItemDecoration(dividerItemDecoration);
  
      getDocumentsFromCollection();
  
  
      return view;
  
  }
  
  @Override
  public void onAttach(Context context) {
      super.onAttach(context);
  }
  
  
  public void getDocumentsFromCollection() {
      firestoreDB.collection("products").get()
              .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
                  @Override
                  public void onComplete(@NonNull Task<QuerySnapshot> task) {
                      if (task.isSuccessful()) {
                          //List<Event> eventList = new ArrayList<>();
                          List<DocumentSnapshot> documents = task.getResult().getDocuments();
  
  
                          ProductAdapter recyclerViewAdapter = new ProductAdapter(documents, getActivity(), firestoreDB);
  
  
  
                          recyclerViewAdapter.setOnItemClickListener(new ProductAdapter.ClickListener() {
                              @Override
                              public void onItemClick(int position, View v) {
                                  Log.d(TAG, "onItemClick position: " + position);
  
                                      // Go to the details page for the selected product
  
  
  
                                  }
  
                          });
  
                          productRecyclerView.setAdapter(recyclerViewAdapter);
  
  
                      } else {
                          Log.d(TAG, "Error getting documents: ", task.getException());
                      }
                  }
              });
  
      firestoreDB.collection("products")
              .addSnapshotListener(getActivity(), new EventListener<QuerySnapshot>() {
                  @Override
                  public void onEvent(QuerySnapshot documentSnapshots, FirebaseFirestoreException e) {
  
  
                  }
              });
        }
  
  
   }
  

• Adapter

  public class ProductAdapter  extends RecyclerView.Adapter<ProductAdapter.ViewHolder>{
  
  public static ClickListener clickListener;
  
  public List<DocumentSnapshot> documents;
  private Context context;
  private FirebaseFirestore firestoreDB;
  
  public ProductAdapter(List<DocumentSnapshot> list, Context ctx, FirebaseFirestore firestore) {
      documents = list;
      context = ctx;
      firestoreDB = firestore;
  }
  
  @Override
  public int getItemCount() {
      return documents.size();
  }
  
  @Override
  public ProductAdapter.ViewHolder
  onCreateViewHolder(ViewGroup parent, int viewType) {
  
      View view = LayoutInflater.from(parent.getContext())
              .inflate(R.layout.list_layout, parent, false);
  
      ProductAdapter.ViewHolder viewHolder =
              new ProductAdapter.ViewHolder(view);
      return viewHolder;
  }
  
  @Override
  public void onBindViewHolder(ProductAdapter.ViewHolder holder, int position) {
      final int itemPos = position;
      final DocumentSnapshot snapshot = documents.get(position);
      holder.item_name.setText(snapshot.getString("Product"));
      holder.price.setText("Rs " + snapshot.getString("Cost") + "/" + snapshot.getString("Per"));
  
  
  }
  
  public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
  
      public TextView item_name;
      public TextView price;
  
  
      public ViewHolder(View view) {
          super(view);
          itemView.setOnClickListener(this);
          item_name = view.findViewById(R.id.List_maintext);
          price = view.findViewById(R.id.List_subtext);
  
      }
  
      @Override
      public void onClick(View v) {
          clickListener.onItemClick(getAdapterPosition(), v);
  
      }
  }
  public void setOnItemClickListener(ClickListener clickListener) {
      ProductAdapter.clickListener = clickListener;
  
  
  }
  
  public interface ClickListener {
      void onItemClick(int position, View v);
  
  }
  
  }
  

I tried some methods but all of them crashed. I need to show a detailed view of the item clicked

Answer 1

You can something like this: Create POJO class and get data from this class.

POJO.class

public class Info {
String product;
String cost;
String per;
@Exclude
private String key;

public Info(){
}

public Info(String product, String cost, String per){
this.product = product;
this.cost = cost;
this.per = per;
}

public <T extends Info> T withId(@NonNull final String id) {
    this.key = id;
    return (T) this;
}

public String getProduct() {
    return product;
}

public void setProduct(String product) {
    this.product = product;
}

public String getCost() {
    return cost;
}
public void setCost(String cost) {
    this.cost = cost;
}

public String getPer() {
    return per;
}


public void setPer(String per) {
    this.per = per;
}
}

Your fragment, your method

  List<Info> documents = new ArrayList<>(); //before onCreate method
  public void getDocumentsFromCollection() {
  firestoreDB.collection("products").get()
        .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
            @Override
            public void onComplete(@NonNull Task<QuerySnapshot> task) {
                if (task.isSuccessful()) {
      for (DocumentSnapshot snap : task.getResult()){
                   Info model =snap.toObject(Info.class).withID(snap.getID());

   documents.add(model);


                    ProductAdapter recyclerViewAdapter = new     ProductAdapter(documents, getActivity(), firestoreDB);



                    recyclerViewAdapter.setOnItemClickListener(new ProductAdapter.ClickListener() {
                        @Override
                        public void onItemClick(int position, View v) {
                            Log.d(TAG, "onItemClick position: " + position);

                                // Go to the details page for the selected       product



                            }

                    });

                    productRecyclerView.setAdapter(recyclerViewAdapter);
                    productRecyclerView.notifyDataSetChanged();
       }

                } else {
                    Log.d(TAG, "Error getting documents: ", task.getException());
                }
            }
        });

firestoreDB.collection("products")
        .addSnapshotListener(getActivity(), new EventListener<QuerySnapshot>() {
            @Override
            public void onEvent(QuerySnapshot documentSnapshots, FirebaseFirestoreException e) {


            }
        });
  }

Adapter your:

public class ProductAdapter  extends  RecyclerView.Adapter<ProductAdapter.ViewHolder>{

public static ClickListener clickListener;

public List<Info> documents;
private Activity context;
private FirebaseFirestore firestoreDB;

public ProductAdapter(List<Info> list, Activitx ctx,   FirebaseFirestore firestore) {
documents = list;
context = ctx;
firestoreDB = firestore;
}

@Override
 public int getItemCount() {
 return documents.size();
 }

@Override
public ProductAdapter.ViewHolder
 onCreateViewHolder(ViewGroup parent, int viewType) {

 View view = LayoutInflater.from(parent.getContext())
        .inflate(R.layout.list_layout, parent, false);

 ProductAdapter.ViewHolder viewHolder =
        new ProductAdapter.ViewHolder(view);
 return viewHolder;
}

@Override
 public void onBindViewHolder(ProductAdapter.ViewHolder holder, int position) {
 final int itemPos = position;
 final Info model = documents.get(position);
 holder.item_name.setText(model.getProduct());
  holder.price.setText("Rs " + model.getCost() + "/" +  model.getPer());

  holder.itemView.setOnClicListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               Intent openNewActivity = new Intent(context, YourNewActivity.class);
              openNewActivity.putExtra("id", model.getId());
              openNewActivity.putExtra("product", model.getProduct());
              context.startActivity(openNewActivity);
            }
        }); 


 }

 public class ViewHolder extends RecyclerView.ViewHolder implements      View.OnClickListener {

  public TextView item_name;
  public TextView price;


     public ViewHolder(View view) {
     super(view);
     itemView.setOnClickListener(this);
     item_name = view.findViewById(R.id.List_maintext);
     price = view.findViewById(R.id.List_subtext);

  }

 @Override
  public void onClick(View v) {
    clickListener.onItemClick(getAdapterPosition(), v);

  }
  } 
  public void setOnItemClickListener(ClickListener clickListener) {
  ProductAdapter.clickListener = clickListener;


}

public interface ClickListener {
void onItemClick(int position, View v);

}

}

You can try something like this, I think this can help you to solve your problem. P.S. Sorry for my english.