i need to get bestseller values from AGS Biryani in recyler view , No idea about how to add the child values to the recyler adapter based on parent node
Model
public class Food_List {
private String itemname;
private String itemdescrp;
private long itemnewprice;
private long itemoldprice;
public String getItemname() {
return itemname;
}
public void setItemname(String itemname) {
this.itemname = itemname;
}
public String getItemdescrp() {
return itemdescrp;
}
public void setItemdescrp(String itemdescrp) {
this.itemdescrp = itemdescrp;
}
public long getItemnewprice() {
return itemnewprice;
}
public void setItemnewprice(long itemnewprice) {
this.itemnewprice = itemnewprice;
}
public long getItemoldprice() {
return itemoldprice;
}
public void setItemoldprice(long itemoldprice) {
this.itemoldprice = itemoldprice;
}
}
Food_List_ViewHolders
ViewHolders to add the value in Recyler view
public class Food_List_ViewHolders extends RecyclerView.ViewHolder {
View mView;
private Context context;
Context mContext;
String nodata;
public Food_List_ViewHolders(View itemView) {
super(itemView);
mView=itemView;
}
#SuppressLint("SetTextI18n")
public void setDetails(Context applicationContext, final String itemname, String itemdescrp,
final long itemnewprice,
final long itemoldprice
)
{
final TextView dishitemname=mView.findViewById(R.id.dishheader);
TextView dishitemnamedescrp=mView.findViewById(R.id.dishheaderdescrp);
TextView dishitemnameoldprice=mView.findViewById(R.id.itemoldprice);
TextView dishitemnamenewprice=mView.findViewById(R.id.itemnewprice);
dishitemname.setText(itemname);
dishitemnamedescrp.setText(itemdescrp);
dishitemnamenewprice.setText(applicationContext.getString(R.string.Rup) + itemnewprice);
dishitemnameoldprice.setText(applicationContext.getString(R.string.Rup) + itemoldprice);
mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View mView) {
Context context = mView.getContext();
}
});
}
}
Main Activity
Don't Know how to add Child values in DataSnapshot
mRecycleriew =findViewById(R.id.my_recycler_views);
mRecycleriew.setLayoutManager(new LinearLayoutManager(this));
mFirebaseDatabase= FirebaseDatabase.getInstance();
mRef=mFirebaseDatabase.getReference().child("restaurants").equalTo("AGS Biryani");
//DatabaseReference restaurantsRef = mRef.child("restaurants");
mRef(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot ds : dataSnapshot.getChildren()){
progressDoalog.dismiss();
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
private void mRef(ValueEventListener valueEventListener) {
}
protected void onStart() {
super.onStart();
FirebaseRecyclerAdapter<Food_List,Food_List_ViewHolders> firebaseRecyclerAdapter=
new FirebaseRecyclerAdapter<Food_List, Food_List_ViewHolders>(
Food_List.class,
R.layout.item_child,
Food_List_ViewHolders.class,
mRef)
{
#Override
protected void populateViewHolder(Food_List_ViewHolders viewHolder, Food_List model, int position) {
viewHolder.setDetails(getApplicationContext(),model.getItemname(),model.getItemdescrp(),model.getItemnewprice(),model.getItemoldprice());
}
};
mRecycleriew.setAdapter(firebaseRecyclerAdapter);
}
Essentially you're doing:
mRef=mFirebaseDatabase.getReference().child("restaurants").equalTo("AGS Biryani");
FirebaseRecyclerAdapter<Food_List,Food_List_ViewHolders> firebaseRecyclerAdapter=
new FirebaseRecyclerAdapter<Food_List, Food_List_ViewHolders>(
Food_List.class,
R.layout.item_child,
Food_List_ViewHolders.class,
mRef)
Which means that you're showing all restaurants with a priority of AGS Biryani. That's not what you're trying to do, so you'll need to modify your ref:
mRef=mFirebaseDatabase.getReference().child("restaurants/AGS Biryani/bestsellers");
When you pass this ref into the FirebaseRecyclerAdapter, it will show all bestsellers for AGS Biryani.
Related
I'm working on this project where users are able to upload more than one character image along with other information. Such as the name of the character, what the character will do, the color of the character and its height. Now everything saves successfully in the database. However, when I want to display all of the character's information on the user's profile page, using a recyclerView, the saved information in the database will not display on the user's profile page. Below is my code. Thanks in advance
//Users profile page
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_profile);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_NOSENSOR);
overridePendingTransition(R.anim.slide_right, R.anim.slide_left);
mUploads = new ArrayList<>();
mAdapter = new ImageAdapter(getApplicationContext(), mUploads);
recyclerView = findViewById(R.id.recyclerView);
//recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setAdapter(mAdapter);
mAdapter.notifyDataSetChanged();
if (firebaseAuth != null) {
databaseReference = FirebaseDatabase.getInstance().getReference("Users");
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
firebaseStorage = FirebaseStorage.getInstance();
storageReference = firebaseStorage.getReference();
//upload = findViewById(R.id.button_upload);
//button2 = findViewById(R.id.submit);
//imageView = findViewById(R.id.view_image);
//upload.setOnClickListener(this);
databaseReference.child(uid).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot postsnapshot : dataSnapshot.getChildren()) {
String imageUrl = (String) postsnapshot.child("mImageUrl").getValue();
mUploads.add(imageUrl);
//mUploads = new ArrayList<>();
}
mAdapter.notifyDataSetChanged();
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Toast.makeText(ProfileActivity.this, databaseError.getMessage(), Toast.LENGTH_LONG).show();
}
});
}
}
//Model Upload.class
public class Upload {
private String mImageUrl;
public Upload(){
//Empty constructor needed
}
public Upload (String imageUrl){
mImageUrl=imageUrl;
}
public String getmImageUrl() {
return mImageUrl;
}
public void setmImageUrl(String mImageUrl) {
this.mImageUrl = mImageUrl;
}
}
// Image adapter class
public class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ImageViewHolder>{
private Context mContext;
private List<String> mUploads;
public ImageAdapter(Context context, List<String> uploads){
mContext = context;
mUploads = uploads;
}
#NonNull
#Override
public ImageViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View V = LayoutInflater.from(mContext).inflate(R.layout.cardview, parent, false);
return new ImageViewHolder(V);
}
#Override
public void onBindViewHolder(#NonNull ImageViewHolder holder, int position) {
String uploadCurrent=mUploads.get(position);
Picasso.get().load(uploadCurrent).fit().centerCrop().into(holder.imageView);
}
#Override
public int getItemCount() {
return mUploads.size();
}
public class ImageViewHolder extends RecyclerView.ViewHolder{
public ImageView imageView;
public ImageViewHolder(#NonNull View itemView) {
super(itemView);
imageView=itemView.findViewById(R.id.imageview);
}
}
}
Change this:
databaseReference.child(uid).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot postsnapshot : dataSnapshot.getChildren()) {
String imageUrl = (String) postsnapshot.child("mImageUrl").getValue();
mUploads.add(imageUrl);
//mUploads = new ArrayList<>();
}
mAdapter.notifyDataSetChanged();
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Toast.makeText(ProfileActivity.this, databaseError.getMessage(), Toast.LENGTH_LONG).show();
}
});
into this:
databaseReference.child(uid).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot postsnapshot : dataSnapshot.getChildren()) {
String imageUrl = postsnapshot.child("mImageUrl").getValue(String.class);
mUploads.add(imageUrl);
//mUploads = new ArrayList<>();
mAdapter.notifyDataSetChanged();
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Toast.makeText(ProfileActivity.this, databaseError.getMessage(), Toast.LENGTH_LONG).show();
}
});
If you want to read inside the children of children, you need to do double loop like this.
databaseReference.child(uid).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot postsnapshot : dataSnapshot.getChildren()) {
for (DataSnapshot snapshot : postsnapshot.getChildren()) {
String imageUrl = snapshot.child("mImageUrl").getValue(String.class);
mUploads.add(imageUrl);
//mUploads = new ArrayList<>();
}
}
mAdapter.notifyDataSetChanged();
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Toast.makeText(ProfileActivity.this, databaseError.getMessage(), Toast.LENGTH_LONG).show();
}
});
Edited:
If you want to pass all of them, you need to change a bit of your model class
public class Upload {
private String mImageUrl;
private String Character_Name;
private String What_Character_Does;
private String color;
private String height;
public Upload() {
//Empty constructor needed
}
public Upload(String imageUrl) {
mImageUrl = imageUrl;
}
public String getmImageUrl() {
return mImageUrl;
}
public void setmImageUrl(String mImageUrl) {
this.mImageUrl = mImageUrl;
}
public String getCharacter_Name() {
return Character_Name;
}
public void setCharacter_Name(String character_Name) {
Character_Name = character_Name;
}
public String getWhat_Character_Does() {
return What_Character_Does;
}
public void setWhat_Character_Does(String what_Character_Does) {
What_Character_Does = what_Character_Does;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}
public String getHeight() {
return height;
}
public void setHeight(String height) {
this.height = height;
}
}
I tried so many solutions about this, but none of this resolve my problem. I can not reach the database using recyclerview. I have firebase realtime database data like this;
Tag
--- Main Category
----- keyID
------ main-Category, sub-category
Tags class
public class Tags {
private String id;
private String mainTags;
private String subTags;
public Tags() {}
public Tags(String id, String mainTags, String subTags) {
this.id = id;
this.mainTags = mainTags;
this.subTags = subTags;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getMainTags() {
return mainTags;
}
public void setMainTags(String mainTags) {
this.mainTags = mainTags;
}
public String getSubTags() {
return subTags;
}
public void setSubTags(String subTags) {
this.subTags = subTags;
}
}
and this is TagAdapter
public class TagAdapter extends RecyclerView.Adapter<TagAdapter.ItemViewHolder> {
private List<Tags> mTagList;
private Context mContext;
public TagAdapter(List<Tags> mTagList, Context mContext) {
this.mTagList = mTagList;
this.mContext = mContext;
}
#NonNull
#Override
public ItemViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.each_item_tags, parent,false);
return new ItemViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ItemViewHolder holder, int position) {
Tags tags = mTagList.get(position);
holder.tvTags.setText(tags.getSubTags());
holder.tvMainTags.setText(tags.getMainTags());
}
#Override
public int getItemCount() {
return mTagList.size();
}
public class ItemViewHolder extends RecyclerView.ViewHolder{
private TextView tvMainTags, tvTags;
public ItemViewHolder(#NonNull View itemView) {
super(itemView);
tvMainTags = itemView.findViewById(R.id.tvMainTag);
tvTags = itemView.findViewById(R.id.tvTags);
}
}
}
TagsFragment
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_tags, container, false);
rvTags = view.findViewById(R.id.rvTags);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext());
linearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
rvTags.setLayoutManager(linearLayoutManager);
rvTags.hasFixedSize();
tagAdapter = new TagAdapter(tagsList, getContext());
rvTags.setAdapter(tagAdapter);
return view;
}
private void getTagView(){
FirebaseDatabase firebaseDatabase = FirebaseDatabase.getInstance();
DatabaseReference dbRefTags = firebaseDatabase.getReference().child("Tag");
dbRefTags.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(#NonNull DataSnapshot dataSnapshot, #Nullable String s) {
for (DataSnapshot ds : dataSnapshot.getChildren()){
if (ds.exists()) {
try {
Tags tags = ds.getValue(Tags.class);
tagsList.add(tags);
}catch (Exception e){
Toast.makeText(getContext(), e.getMessage(), Toast.LENGTH_LONG).show();
}
}else {
Toast.makeText(getContext(), "Bir hata oluştu", Toast.LENGTH_SHORT).show();
}
}
tagAdapter.notifyDataSetChanged();
}
#Override
public void onChildChanged(#NonNull DataSnapshot dataSnapshot, #Nullable String s) {
}
#Override
public void onChildRemoved(#NonNull DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(#NonNull DataSnapshot dataSnapshot, #Nullable String s) {
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
There is no error show up when running but i couldn't be able to retrieve data. And i tried firebaseRecyclerView.Adapter also and in the last dependency, i couldn't make it work. I don't know what is wrong in here. how can i solve this?
Get The data with child name ds.child("SubTag").getValue()
dbRefTags.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot parentDS : dataSnapshot.getChildren()) {
Log.d("Tag:", String.valueOf(parentDS.getKey()));
for (DataSnapshot ds : parentDS.getChildren()) {
Tags tags = new Tags();
tags.setMainTag(parentDS.getKey());
tags.setSubTag(ds.child("SubTag").getValue().toString());
Log.d("Tag: -> SubTag)", tags.getSubTag());
tagsList.add(tags);
}
}
tagAdapter.notifyDataSetChanged();
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Toast.makeText(getContext(), databaseError.getMessage(), Toast.LENGTH_SHORT).show();
}
});
I want to hide the current user in RequestsFragment in recyclerview. I tried to setVisibility feature. The current user's informantions are not seen to him. But there is a space still in recyclerview. How can i also delete space between other items. I mean if I have sent a request to other users I dont want to see myself at requests fragment.
public class RequestsFragment extends Fragment {
private RecyclerView recyclerView_friendRequestsList;
private View mainView;
private DatabaseReference friendRequestsDatabaseReference;
private DatabaseReference usersDatabaseReference;
private FirebaseAuth firebaseAuth;
private String current_user_id;
public RequestsFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
mainView = inflater.inflate(R.layout.fragment_requests, container, false);
recyclerView_friendRequestsList = mainView.findViewById(R.id.friendRequests_list);
recyclerView_friendRequestsList.setHasFixedSize(true);
recyclerView_friendRequestsList.setLayoutManager(new LinearLayoutManager(getContext()));
firebaseAuth = FirebaseAuth.getInstance();
current_user_id = firebaseAuth.getCurrentUser().getUid();
friendRequestsDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Friend Requests");
friendRequestsDatabaseReference.keepSynced(true);
usersDatabaseReference = FirebaseDatabase.getInstance().getReference().child("Users");
usersDatabaseReference.keepSynced(true);
return mainView;
}
#Override
public void onStart() {
super.onStart();
final FirebaseRecyclerAdapter<FriendRequests, RequestsFragment.FriendRequestsViewHolder> firebaseRecyclerAdapter = new FirebaseRecyclerAdapter<FriendRequests, FriendRequestsViewHolder>(
FriendRequests.class,
R.layout.users_single_layout,
RequestsFragment.FriendRequestsViewHolder.class,
friendRequestsDatabaseReference
) {
#Override
protected void populateViewHolder(final FriendRequestsViewHolder viewHolder, FriendRequests model, final int position) {
final String user_id = getRef(position).getKey();
friendRequestsDatabaseReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.hasChild(user_id)){
usersDatabaseReference.child(user_id).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (!user_id.equals(current_user_id)) {
final String user_displayName = dataSnapshot.child("display_name").getValue().toString();
final String user_thumbImage = dataSnapshot.child("thumb_image").getValue().toString();
if (dataSnapshot.hasChild("online")) {
String userOnline = dataSnapshot.child("online").getValue().toString();
viewHolder.setUserOnline(userOnline);
}
viewHolder.setName(user_displayName);
viewHolder.setImage(user_thumbImage);
viewHolder.mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent profileIntent = new Intent(getContext(), ProfileActivity.class);
profileIntent.putExtra("user_id", user_id);
startActivity(profileIntent);
}
});
} else {
viewHolder.mView.setVisibility(View.GONE);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
friendRequestsDatabaseReference.child(current_user_id).child(user_id).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.hasChild("request_type")) {
String request_type = dataSnapshot.child("request_type").getValue().toString();
viewHolder.setRequest_type(request_type);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
};
recyclerView_friendRequestsList.setAdapter(firebaseRecyclerAdapter);
}
public static class FriendRequestsViewHolder extends RecyclerView.ViewHolder {
View mView;
public FriendRequestsViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
public void setName(String name) {
TextView userNameView = mView.findViewById(R.id.user_single_displayName);
userNameView.setText(name);
}
public void setRequest_type(String request_type) {
TextView userStatusView = mView.findViewById(R.id.user_single_status);
userStatusView.setText(request_type);
}
public void setImage(final String thumb_image) {
CircleImageView userImageView = mView.findViewById(R.id.user_single_image);
Picasso.get().load(thumb_image).placeholder(R.mipmap.default_avatar).into(userImageView);
}
public void setUserOnline(String online_status) {
ImageView userOnlineView = mView.findViewById(R.id.user_single_online);
if (online_status.equals("true")) {
userOnlineView.setVisibility(View.VISIBLE);
} else {
userOnlineView.setVisibility(View.INVISIBLE);
}
}
}
}
Tried answers found on the internet, actually there is no change to the code as it seem correct but can't find where is the error.
My Input Parameters:
JSON RETURNED:
(I expected a "clocation" child and value but it won't even write that to the tree. Plus, the value of clocation is written to cbudget)
Project Class:
public class Project {
String ctitle, cdetail, clocation, cbudget;
public Project() {
}
public String getCtitle() {
return ctitle;
}
public void setCtitle(String ctitle) {
this.ctitle = ctitle;
}
public String getCdetail() {
return cdetail;
}
public void setCdetail(String cdetail) {
this.cdetail = cdetail;
}
public String getClocation() {
return clocation;
}
public void setClocation(String clocation) {
this.clocation = clocation;
}
public String getCbudget() {
return cbudget;
}
public void setCbudget(String cbudget) {
this.cbudget = cbudget;
}
MyViewHolder
public MyViewHolder(View itemView) {
super(itemView);
titleTxt = (TextView) itemView.findViewById(R.id.titleTxt);
detailTxt = (TextView) itemView.findViewById(R.id.detailTxt);
locationTxt = (TextView) itemView.findViewById(R.id.locationTxt);
budgetTxt = (TextView) itemView.findViewById(R.id.budgetTxt);
itemView.setOnClickListener(this);
}
MyAdapter
public MyAdapter(Context c, ArrayList<Project> projects) {
this.c = c;
this.projects = projects;
}
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(c).inflate(R.layout.model,parent,false);
return new MyViewHolder(v);
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
final Project s = projects.get(position);
holder.titleTxt.setText(s.getCtitle());
holder.detailTxt.setText(s.getCdetail());
holder.locationTxt.setText(s.getClocation());
holder.budgetTxt.setText(s.getCbudget());
holder.setItemClickListener(new ItemClickListener() {
#Override
public void onItemClick(int pos) {
//OPEN DETAIL ACTIVITY
openDetailActivity(s.getCtitle(),s.getCdetail(),s.getClocation(),s.getCbudget());
}
});
}
#Override
public int getItemCount() {
return projects.size();
}
//OPEN DETAIL ACTIVITY
private void openDetailActivity(String...details)
{
Intent i=new Intent(c,DetailActivity.class);
i.putExtra("TITLE_KEY",details[0]);
i.putExtra("DETAIL_KEY",details[1]);
i.putExtra("LOCATION_KEY",details[2]);
i.putExtra("BUDGET_KEY",details[3]);
c.startActivity(i);
}
FirebaseHelper
public class FirebaseHelper {
DatabaseReference db;
Boolean saved = null;
ArrayList<Project> projects=new ArrayList<>();
public FirebaseHelper(DatabaseReference db) {
this.db = db;
}
//WRITE IF NOT NULL
public Boolean save(Project project)
{
if(project==null)
{
saved=false;
}
else
{
try
{
db.child("Project").push().setValue(project);
saved=true;
}catch (DatabaseException e)
{
e.printStackTrace();
saved=false;
}
}
return saved;
}
//IMPLEMENT FETCH DATA AND FILL ARRAYLIST
private void fetchData(DataSnapshot dataSnapshot)
{
projects.clear();
for (DataSnapshot ds : dataSnapshot.getChildren())
{
Project project = ds.getValue(Project.class);
projects.add(project);
}
}
//READ THEN RETURN ARRAYLIST
public ArrayList<Project> retrieve() {
db.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
fetchData(dataSnapshot);
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
return projects;
}
}
Receive and Bind Data:
//RECEIVE DATA
String title = i.getExtras().getString("TITLE_KEY");
String detail = i.getExtras().getString("DETAIL_KEY");
String location = i.getExtras().getString("LOCATION_KEY");
String budget = i.getExtras().getString("BUDGET_KEY");
//BIND DATA
titleTxt.setText(title);
detailTxt.setText(detail);
locationTxt.setText(location);
budgetTxt.setText(budget);
The problem in your code is that you are declaring the ArrayList<Project> projects=new ArrayList<>(); outside onChildAdded() and onChildChanged() methods. This means that your projects ArrayList is null, due the asyncronious behaviour of those methods, which are called before even you add those objects to the list.
To solve this, you need to declare that ArrayList inside fetchData() method right before that for loop.
This change will solve your problem.
I'm new to Firebase. I'm trying to query the firebase database and display all the child objects of the results in a ListView. I've no errors but nothing is being displayed. It doesn't crash but it doesn't do anything either. Please help me out.
The contents of my database:
Here's my code for data retrieval:
imgbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
key = search.getText().toString().trim();
Firebase newRef = new Firebase("https://stockmanager-142503.firebaseio.com/Items");
Query query = newRef.orderByChild("Idno").equalTo(key);
query.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Map<String,Item> td = (HashMap<String,Item>) dataSnapshot.getValue();
List<Item> valuesToMatch = new ArrayList<Item>(td.values());
myAdapter myadapter=new myAdapter(getActivity(),valuesToMatch);
mlistView.setAdapter(myadapter);
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(FirebaseError firebaseError) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setMessage(firebaseError.getMessage())
.setTitle("Error!")
.setPositiveButton(android.R.string.ok, null);
AlertDialog dialog = builder.create();
dialog.show();
}
});
Here's my adapter class:
public class myAdapter extends BaseAdapter {
private List<Item> items;
private Context mContext;
public myAdapter(Context mContext, List<Item> items) {
this.mContext=mContext;
this.items=items;
}
#Override
public int getCount() {
return 0;
}
#Override
public Object getItem(int i) {
return null;
}
#Override
public long getItemId(int i) {
return 0;
}
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
LinearLayout linearLayout;
Item item=items.get(i);
if (view == null) {
linearLayout = (LinearLayout) LayoutInflater.from(mContext).inflate(R.layout.rowitem, viewGroup, false);
} else {
linearLayout = (LinearLayout)view;
}
TextView text1=(TextView)linearLayout.findViewById(R.id.text1);
TextView text2=(TextView)linearLayout.findViewById(R.id.text2);
TextView text3=(TextView)linearLayout.findViewById(R.id.text3);
TextView text4=(TextView)linearLayout.findViewById(R.id.text4);
TextView text5=(TextView)linearLayout.findViewById(R.id.text5);
text1.setText(item.getIdno());
text2.setText(item.getName());
text3.setText(item.getBrand());
text4.setText(item.getCost());
text5.setText(item.getDate());
return null;
}
}
Here is the item class:
public class Item {
private String Type;
private String Name;
private String Brand;
private String Cost;
private String Date;
private String Store;
private String Idno;
public String getName() {
return Name;
}
public String getIdno() {
return Idno;
}
public String getCost() {
return Cost;
}
public void setDate(String date) {
Date = date;
}
public String getBrand() {
return Brand;
}
public String getStore() {
return Store;
}
public String getType() {
return Type;
}
public String getDate() {
return Date;
}
}
I fixed it myself. Apparently, the query returned a list of objects and hence I replaced the Hashmap with a for loop to getchildren and add them to a List. But my listview simply wouldn't display the retreived data. Finally, I used the firebase UI List Adpater given below and that fixed it. Thanks everyone!
imgbtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
key = scanContent;
Query q = dbRef.orderByChild("idno").equalTo(key);
FirebaseListAdapter<Item> adapter =new FirebaseListAdapter<Item>(getActivity(),Item.class,R.layout.rowitem,q) {
#Override
protected void populateView(View v, Item item, int position) {
TextView text1=(TextView)v.findViewById(R.id.text1);
TextView text2=(TextView)v.findViewById(R.id.text2);
TextView text3=(TextView)v.findViewById(R.id.text3);
TextView text4=(TextView)v.findViewById(R.id.text4);
TextView text5=(TextView)v.findViewById(R.id.text5);
text1.setText(item.getIdno());
text2.setText(item.getName());
text3.setText(item.getBrand());
text4.setText(item.getCost());
text5.setText(item.getDate());
solditem=item;
}
};
sell.setText("Add this result to Sold Items List?");
sList.setAdapter(adapter);
}
});