I want to show all data into Recycleview but only first image load other are not
shown recycleviewList anybody have idea about this.
mFirebaseInstance = FirebaseDatabase.getInstance();
// get reference to 'users' node
mFirebaseDatabase = mFirebaseInstance.getReference("items");
mFirebaseDatabase.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String getImage= (String) dataSnapshot.getValue();
String ConvertImage;
ConvertImage = getImage.replaceAll("\\[",
"").replaceAll("\\]","");
String[] items = ConvertImage.split(",");
List<String> list = Arrays.asList(items);
Log.e("list",list.toString());
for (String item : list) {
arraylist.add(item);
setImg(arraylist);
}
}
#Override
public void onCancelled(DatabaseError error) {
// Failed to read value
}
});
To get all those link, please use the following code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference itemsRef = rootRef.child("items");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String link = ds.getValue(String.class);
Log.d("TAG", link);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
itemsRef.addListenerForSingleValueEvent(eventListener);
The output will contain, all those links from your item node.
If you are able to retrieve all the links and still only one image loads, then check the xml layout of single list item of RecyclerView and make sure the height is wrap_content and NOT match_parent like this
android:layout_height="wrap_content"
Related
I have a database in fire-base. In that I have a child node named "item1", under item1 i have two values
name
prize
I want to retrieve the name of item1 and I want to put it in a string called "foodname". How can I do that?
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference("menu");
Here I tried but did not find solution
String foodname; //this string should get the value as "diary milk"
mDatabase.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference();
mDatabase.child("menu").addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
//This will loop through all items. Add variables to arrays or lists as required
for (DatasnapShot snap : dataSnapshot.getChildren())
{
foodname = dataSnapshot.child("name").getValue().toString();
String prize = dataSnapshot.child("prize").getValue().toString();
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
You can fetch each child individually like such. Or you can make use of a Model or a Hashmap to fetch all of the data and then fetch the data you would like based on the Key
Using below code you can get food name
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference("menu");
mDatabase.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
String foodName = snapshot.child("name").getValue().toString();
String foodPrice = snapshot.child("prize").getValue().toString();
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
Retrieving any data from Firebase requires a correct database reference and eventListeners that can work for what you want.
To know more about eventListeners visit this link.
DatabaseReference ref = FirebaseDatabase.getInstance().getReference().child("menu").child("item1");
ref.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
// this code will get only details from item1
foodname = dataSnapshot.child("name").getValue(String.class);
String price = dataSnapshot.child("prize").getValue(Integer.class);
//if you want details from multiple items, you have to loop over the child nodes like this
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
foodname = snapshot.child("name").getValue().toString();
String price = snapshot.child("prize").getValue().toString();
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
I want to implement followers functionality in my android application. 'First' image refers to the list of user i followed. 'second' image have all ids of all the posts that users post and 'third' image havin post details. all i want to do is to load only the post of those users that i've followed.
What i am doing is, i get emails from followers node and by using indexed recyclerview i load the data but its not working because recyclerview is not getting dynamic reference. Any sugested solution ?
first
second
third
In order to achieve this, you need to query your database for three times like this:
FirebaseUser firebaseUser = firebaseAuth.getCurrentUser();
String userEmail = firebaseUser.getEmail();
String encodedUserEmail = userEmail.replace(".", ",");
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference userEmailFromFollowersRef = rootRef.child("followers").child(encodedUserEmail);
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String followerEmail = ds.getKey();
DatabaseReference my_postsRef = rootRef.child("my_posts").child(followerEmail);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot dSnapshot : dataSnapshot.getChildren()) {
String postId = dSnapshot.getKey();
DatabaseReference postsRef = rootRef.child("posts").child(postId);
ValueEventListener vel = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot child : dataSnapshot.getChildren()) {
String postText = child.child("postText").getValue(String.class);
Log.d("TAG", postText);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
postsRef.addListenerForSingleValueEvent(vel);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
my_postsRef.addListenerForSingleValueEvent(valueEventListener);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
userEmailFromFollowersRef.addListenerForSingleValueEvent(eventListener);
I have product child in my database, and I need to retrieve all its children as a list so I can view it in my app in list view.
how can I do it?
thank you.
To get those products, please use the following code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference productsRef = rootRef.child("products");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String product = ds.getKey();
Log.d("TAG", product);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
productsRef.addListenerForSingleValueEvent(eventListener);
Your output will be:
aa
appledd
bb
fruitrtyyty
//an so on
I want to use the spinner to display the key which under specific username but unfortunately it returns nothing to the spinner. I used an array to store the key value which under the username.
Here's my database structure
Let's said I am rexyou0831 and I just want to retrieve the 2 usernames which under my username but my code return me nothing to the list. un is my current username variables. Please if you got any idea please share it with me thank you.
Hers' my code
db = FirebaseDatabase.getInstance();
cref = db.getReference("chat");
public ArrayList<String> retrieve()
{
final ArrayList<String> Student=new ArrayList<>();
cref.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot c:dataSnapshot.getChildren())
{
if(c.getKey().equals(un)){
for(DataSnapshot d: dataSnapshot.getChildren()){
Student.add(d.getKey());
}
}else{
Student.clear();
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
return Student;
}
To get those usernames under your username, please use the following code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference userRef = rootRef.child("chat").child("rexyou0831");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
List<String> list = new ArrayList<>();
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String userName = ds.getKey();
list.add(userName);
}
Log.d("TAG", list);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
userRef.addListenerForSingleValueEvent(eventListener);
Your out put will be: [gigi1212, mario123]
Note, that onDataChenge() is called asynchronous which means that is called even before you are adding those keys to the list. As a conslusion, you need to declare and use that list, inside onDataChenge(), otherwise is null.
I am trying to display all child "name" located in my database tree. My Database tree I used the Map to do so:
GenericTypeIndicator<Map<String, Object>> m = new GenericTypeIndicator<Map<String, Object>>() {};
Map<String, Object> map = snapshot.getValue(m);
String username = (String) map.get("name");
displayName.setText(username);// Display the name
I am displaying all the data into a recyclerView. But for some reasons instead of getting all names(Eva, smith, princess), I am only one which is the lastest one created "princess" being displayed 3 times in my recyclerView layout(princess, princess, princess). Anyone has any idea what I am doing wrong?
Assuming that you have a node named users in which you have all those uid's, to get all those name, please use the code below. Is the easiest way to achieve this.
DatabaseReference yourRef = FirebaseDatabase.getInstance().getReference().child("users");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String userId = (String) dataSnapshot.getKey();
DatabaseReference userIdRef = FirebaseDatabase.getInstance().getReference().child("users").child(userId);
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String name = (String) dataSnapshot.child("name").getValue();
Log.d("TAG", name);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
userIdRef.addListenerForSingleValueEvent(eventListener);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
yourRef.addListenerForSingleValueEvent(eventListener);
Hope it helps.