I would like to retrieve all errand names which are child nodes of a child node in my Firebase DB.
However, I am only able to reference until the 2nd child node(the random key)
Here is my code;
View view = inflater.inflate(R.layout.tab1,container,false);
String r = "Errands";
root = FirebaseDatabase.getInstance().getReference().child(r);
list = (ListView) view.findViewById(R.id.mylistview);
arrayAdapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_list_item_1,list_of_errands);
list.setAdapter(arrayAdapter);
root.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
Set<String> set = new HashSet<String>();
Iterator i = dataSnapshot.getChildren().iterator();
while (i.hasNext()) {
set.add(((DataSnapshot) i.next()).getKey());
}
Kindly Assist
Please use this code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference errandsRef = rootRef.child("Errands");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String key = ds.getKey();
DatabaseReference keyRef = rootRef.child("Errands").child(key);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String Errand = ds.child("Errand").getValue(String.class);
Log.d("TAG", Errand);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
keyRef.addListenerForSingleValueEvent(valueEventListener);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
errandsRef.addListenerForSingleValueEvent(eventListener);
And your output will be:
Go to Strath
//and so on
Hope it helps.
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 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);
I want to make it store private string keyy, but it does not save, what happens? I tried it with textview if it shows the data.
DatabaseReference myRef = FirebaseDatabase.getInstance().getReference().child("Users").child("Customers");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot nodo : dataSnapshot.getChildren()) {
String key = nodo.getKey();
Log.d("TAG", key);
keyy = key;
mSetting.setText(key); // yes, show data
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
myRef.addListenerForSingleValueEvent(eventListener);
mSetting.setText(keyy); // No,show data
I hope this solve your problem
List<String> keyList = new ArrayList();
DatabaseReference myRef = FirebaseDatabase.getInstance().getReference().child("Users").child("Customers");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot nodo : dataSnapshot.getChildren()) {
String key = nodo.getKey();
keyList.add(key);
}
done(keyList);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
myRef.addListenerForSingleValueEvent(eventListener);
public void done(List k)
{
//show keys here
}
Do like this
List<String> keyList=new ArrayList<>();
DatabaseReference myRef = FirebaseDatabase.getInstance().getReference().child("Users").child("Customers");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot nodo : dataSnapshot.getChildren()) {
String key = nodo.getKey();
Log.d("TAG", key);
/*Add all the keys to keyList here*/
keyList.add(key);
}
/*After the loop ends set the list of keys to textview like this*/
if (keyList.size()>0)
{
for (String s : keyList)
{
mSetting.setText(mSetting.getText().toString()+"\n"+s);
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
myRef.addListenerForSingleValueEvent(eventListener);
I want to make a list of dates from the snapshot I get in my firebase database. However when I type the code:
System.out.println(dataSnapshot.getValue());
I get the whole snapshot:
{Date : 2018 - 04 - 11={-L9pZ0HYpBjmvMEL430k={downloadURL="https:...."}
I just want to get a snapshot of the children of dates.
From your snapshot you have to get your child and your element just like this :
private FirebaseDatabase database = FirebaseDatabase.getInstance();
private final DatabaseReference myRef = database.getReference("IndexOfYourDatabse"); //Init your ref at Data
myRef.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String date = messageSnapshot.child("date").getValue().toString(); //acces to child => date
System.out.println(date);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
Get date from your object
mDatabaseReference = FirebaseDatabase.getInstance().getReference().child(whatever);
mDatabaseReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
Person person = snapshot.getValue(Person.class);
date = person.getDate();
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
This worked for me. Creating a hashmap allowed me to get the key values, which were the dates I needed to put in my listview.
databaseReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
HashMap<String, Object> map = (HashMap<String, Object>) dataSnapshot.getValue();
List<String> keys = new ArrayList<>(map.keySet());
for (int i = 0; i < keys.size(); i++) {
System.out.println(keys.get(i));
}
}
#Override
public void onCancelled(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);