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);
Related
I want to search through data in firebase like here:
I have already tried, but it not works
//Query query = FirebaseDatabase.getInstance().getReference(uid).orderByChild("title").startAt(editable.toString()).endAt(editable.toString()+"\uf888");
DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference("categoreis");
Query query = FirebaseDatabase.getInstance().getReference("categoreis").limitToFirst(4).orderByChild("image");
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
list.clear();
for (DataSnapshot data:dataSnapshot.getChildren())
{
for (DataSnapshot ds:data.child("SubAccessories").getChildren())
{
for (DataSnapshot ds1:ds.getChildren())
{
//Log.d("checkData1",ds1.toString());
//Log.d("checkData1",ds1.child("image").getValue(String.class));
}
}
}
If you want to get the image as I see in your question, please use the following lines of code but assuming that the categories node is a direct child of your Firebase database root:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference ref = rootRef.child("categories/Accessories/SubAccessories/Accessories/Grab Bar");
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String image = dataSnapshot.child("image").getValue(String.class);
Log.d("TAG", image);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
ref.addListenerForSingleValueEvent(valueEventListener);
According to your comment, you should loop through the second Accessories node using getChildren() method like this:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference ref = rootRef.child("categories/Accessories/SubAccessories/Accessories");
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String image = dataSnapshot.child("image").getValue(String.class);
Log.d("TAG", image);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
ref.addListenerForSingleValueEvent(valueEventListener);
In practice, people can send requests to each other. What I want to do is to show all the requests sent to one person in that person's profile. I can show all users information with firebase adapter in recyclerview but I could not show only request senders. How can I do? I'd be very happy if you could give an idea to us.
As I understand you want to show the children names of the parent you can use this code.
DatabaseReference ref = FirebaseDatabase.getInstance().getReference().child("Friend_req").child("recieved").child("id_of_reciepent");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String request_sender_id = (String) ds.getKey();
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
ref.addListenerForSingleValueEvent(eventListener);
To display the names only of the friends who sent a friend request, you need to query your database twice. Please use the following code in order to achieve this.
String uid = firebaseAuth.getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference uidRef = rootRef.child("Friend_req").child("recieved").child(uid);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String key = ds.getKey();
DatabaseReference userRef = rootRef.child("Users").child();
ValueEventListener eventListener = new ValueEventListener(key) {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot dSnapshot : dataSnapshot.getChildren()) {
String name = dSnapshot.child("Name").getValue(String.class);
Log.d("TAG", name);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
userRef.addListenerForSingleValueEvent(eventListener);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
uidRef.addListenerForSingleValueEvent(valueEventListener);
Your output will be:
Bob
Second Friend
I have this data structure:
The red arrows points at animal IDs, and the blue arrow points at user IDs. Every user have one or many animals.
I have tried different methods for showing only the animals that have id that is stored in the current user node.
Example: If I have UID = 48onHXIxgDP465j5WW16oo7psNm2 (the first one in "users") I want to show the data from: "dog2" and "dog3".
Now iIhave the following code that gets snapshot from the "animals" node in the database, and then gets data from every child.
myAnimalRef.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
list = new ArrayList<AnimalCard>();
for(DataSnapshot dataSnapshot1 :dataSnapshot.getChildren()){
AnimalCard value = dataSnapshot1.getValue(AnimalCard.class);
AnimalCard animal = new AnimalCard();
String name = value.getName();
int age = value.getAge();
String url = value.getUrl();
animal.setName(name);
animal.setAge(age);
animal.setUrl(url);
list.add(animal);
}
recyclerViewSetAdapter();
progressDialog.dismiss();
}
#Override
public void onCancelled(DatabaseError databaseError) {
Log.d(TAG1, "failed to read value: " + databaseError.toException());
}
});
How can get my code to filter out every animal that does not have their ID in the user node?
The reason I want to make the user get access with an UID stored in the database is because later on I want to make it so that multiple users can get access to the same animal.
To achieve this, you need to query your database twice. Please use the following code:
FirebaseUser firebaseUser = firebaseAuth.getCurrentUser();
String uid = firebaseUser.getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference uidRef = usersRef.child("users").child(uid);
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String aid = ds.getKey();
DatabaseReference animalRef = rootRef.child("animals").child(aid);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dSnapshot) {
int age = dSnapshot.child("age").getValue(Integer.class);
String name = dSnapshot.child("name").getValue(String.class);
String url = dSnapshot.child("url").getValue(String.class);
Log.d("TAG", age + " / " + name + " / " + url);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
animalRef.addListenerForSingleValueEvent(valueEventListener);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
uidRef.addListenerForSingleValueEvent(eventListener);
In which uid is the id of the logged-in user and aid is the id of the animal. Your output will be:
11 / dog1 / http...
12 / dog2 / http...
Hope you find this helpfull.!
Get Object in Your Model Class and Store that Object in List for Further user.!
You can get specific object as well simple using
mdatabaseRef.child("animals").orderByChild().equalTo("value")
and also you can add check on key by orderByKey()
private FirebaseAuth mAuth;
private FirebaseDatabase mdatabase;
private DatabaseReference mdatabaseRef;
mAuth = FirebaseAuth.getInstance();
mdatabase = FirebaseDatabase.getInstance();
mdatabaseRef = mdatabase.getReference();
ArrayList<User> allUserList = new ArrayList<>();
Array<Animal> allAnimalList=new ArrayList<>();
mdatabaseRef.child("animals").addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot childSnapshot : dataSnapshot.getChildren()) {
String key = childSnapshot.getKey();
Animal animal = childSnapshot.getValue(Animal.class);
allAnimalList.add(animal );
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
mdatabaseRef.child("users").addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot childSnapshot : dataSnapshot.getChildren()) {
String key = childSnapshot.getKey();
User user = childSnapshot.getValue(User .class);
allUserList.add(user);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
I ended up taking Alex Mamo's answer and tweak with a litte bit.
This is the code i'am using:
uid = currentUser.getUid();
mRootRef = FirebaseDatabase.getInstance().getReference();
final DatabaseReference myUserRef = mRootRef.child("users").child(uid);
Log.d(TAG1, uid);
myUserRef.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
list = new ArrayList<AnimalCard>();
for(DataSnapshot ds : dataSnapshot.getChildren()){
String aid = ds.getKey();
DatabaseReference myAnimalRef = mRootRef.child("animals");
Query query = myAnimalRef.orderByKey().equalTo(aid);
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot ds2 : dataSnapshot.getChildren()){
AnimalCard value = ds2.getValue(AnimalCard.class);
AnimalCard animal = new AnimalCard();
String name = value.getName();
int age = value.getAge();
String url = value.getUrl();
animal.setName(name);
animal.setAge(age);
animal.setUrl(url);
list.add(animal);
}
recyclerViewSetAdapter();
progressDialog.dismiss();
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
The main difference is that i'am using a query to filter out every Animal that does not have the aID that the currentUser have.
I have a problem regarding querying the firebase database using a value and getting the specific node. My schema is shown here:
In my schema 'workLocations' belongs to an 'excavationWorks', and 'excavationWorks' belongs to an 'excavationLists'.
That means that the path to a specific workLocation is excavationLists/excavationWorks/workLocations/(specific workLocation)
The problem that I have is that I want to query the workLocations node by the location value (let's say London) and get the parent node (the red circled key which is the key of the specific workLocation).
I have search and read many posts but I haven't managed to make it work.
My code looks like this:
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
Query query = reference.child("workLocations").orderByChild("location").equalTo("London");
query.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot workLoc : dataSnapshot.getChildren()) {
// do something with the individual "issues"
Log.d(TAG, workLoc.getKey());
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
Thank you
To achieve this, you need to query your database twice like this:
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
DatabaseReference workLocationsRef = reference
.child("excavationLists")
.child("excavationWorks")
.child("workLocations");
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot dSnapshot : dataSnapshot.getChildren()) {
for(DataSnapshot ds : dSnapshot.getChildren()) {
String key = ds.getKey();
Query query = workLocationsRef.child(key).orderByChild("location").equalTo("London");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot snapshot) {
String description = snapshot.child("description").getValue(String.class);
Log.d("description", description);
String partentKey = snapshot.getRef().getParent().getKey();
Log.d("partentKey", partentKey);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
query.addListenerForSingleValueEvent(eventListener);
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
workLocationsRef.addListenerForSingleValueEvent(valueEventListener);
My firebase structure looks like this:
The groups use keys generated by firebase, 0 and 1 are just examples.
In those groups there is more data like "groupname".
How should I retrieve the groupnames of all groups linked to a user?
I'm on Android.
Solved by Alex.
Assuming that the groups node is a direct child of your Firebase root and inside a single group, there is a key named groupName, please use the following code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference groupsRef = rootRef.child("groups");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String name = ds.child("name").getValue(String.class);
Log.d("TAG", name);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
Log.d("TAG", task.getException().getMessage()); //Never ignore potential errors!
}
};
groupsRef.addListenerForSingleValueEvent(eventListener);
If you need to be able to get only the group names of the groups that your users are linking to, you need to query twice like this:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference userGroupsRef = rootRef.child("users").child(userKey).child("groups");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String groupKey = ds.getKey();
DatabaseReference groupKeyRef = rootRef.child("groups").child(groupKey);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String name = dataSnapshot.child("name").getValue(String.class);
Log.d("TAG", name);
}
#Override
public void onCancelled(DatabaseError databaseError) {
Log.d("TAG", task.getException().getMessage()); //Never ignore potential errors!
}
};
groupKeyRef.addListenerForSingleValueEvent(valueEventListener);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
Log.d("TAG", task.getException().getMessage()); //Never ignore potential errors!
}
};
userGroupsRef.addListenerForSingleValueEvent(eventListener);
In which userKey is the key of the user from which you want the get the group ids.