Develop Reference

Read data then update it and finish by save it

I need you to help me to solve this problem:
The problem is that I want to read a String called coins from the database of Firebase and then turn it into an Integer value. Then when I push a button I want to add 1 to coins and after that, I turn it back into a String value to save it in the database.
So I tried to do this by using onDataChange to read the data and then use
int score = Integer.parseInt(coins) to turn it into an Integer value called score.
After that, I used onClickListener to add 1 to the integer, but Android Studio tells me:
Cannot resolve score
I don't know how to solve this issue so I would be so happy if you could help me with that thing.
This is my code :
public class HomeFragment extends Fragment {
public HomeFragment() {
// Required empty public constructor
}
//firebase
FirebaseAuth firebaseAuth;
FirebaseUser user;
FirebaseDatabase firebaseDatabase;
DatabaseReference databaseReference;
StorageReference storageReference;
//init view
ImageButton addCoinsBtn;
TextView coinsTv;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view =inflater.inflate(R.layout.fragment_home, container, false);
//init firebase
firebaseAuth = FirebaseAuth.getInstance();
user = firebaseAuth.getCurrentUser();
firebaseDatabase = FirebaseDatabase.getInstance();
databaseReference = firebaseDatabase.getReference("Users");
storageReference = getInstance().getReference();//firebase storage reference
coinsTv=(TextView)view.findViewById(R.id.coinsTv);
addCoinsBtn=(ImageButton)view.findViewById(R.id.add_coins);
Query query = databaseReference.orderByChild("email").equalTo(user.getEmail());
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
//check until required data get
for (DataSnapshot ds : dataSnapshot.getChildren()){
//get data
String coins = ""+ds.child("coins").getValue();
int score = Integer.parseInt(coins);
//set data
coinsTv.setText(score);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
addCoinsBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference coins = database.getReference("Users/"+ user.getUid() +"/coins");
Integer score = score + 1;
String scorefinal = Integer.toString(score);
coins.setValue(scorefinal);
}
});
return view;
}
}
Thank you very much for all your bits of help.

This is a basic scoping problem: variables only exist in the scope where you declare them.
So the int score that you declare in onDataChange is not available in the onClick method anymore.
And the Integer score that you declare in onClick is a new variable, which means that Integer score = score + 1; won't work, because the score on the right-hand side doesn't exist/have a value.
The solution is to declare score one level higher, as a member field of your `` class:
Integer score = -1;
Query query = databaseReference.orderByChild("email").equalTo(user.getEmail());
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot ds : dataSnapshot.getChildren()){
String coins = ""+ds.child("coins").getValue();
score = Integer.parseInt(coins);
coinsTv.setText(score);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
throw databaseError.toException(); // never ignore errors
}
});
addCoinsBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference coinsRef = database.getReference("Users/"+ user.getUid() +"/coins");
score = score + 1;
String scorefinal = Integer.toString(score);
coinsRef.setValue(scorefinal);
}
});
I'd highly recommend storing the value as a number in the database, as it saves you constantly converting from string to integer and back. If you do this, the above code becomes:
Integer score = -1;
Query query = databaseReference.orderByChild("email").equalTo(user.getEmail());
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot ds : dataSnapshot.getChildren()){
score = ds.child("coins").getValue(Integer.class);
coinsTv.setText(score);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
throw databaseError.toException(); // never ignore errors
}
});
addCoinsBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference coinsRef = database.getReference("Users/"+ user.getUid() +"/coins");
coinsRef.setValue(score+1);
}
});

Edit specific values in Firebase database using Android Studio

I want to create an "edit user profile" page on Android Studio. The user(which is logged in obviously) can go in and edit user info such as weight and age. Here is how my firebase database is set up:
The database
In this case, a user who is logged in as "Raxor2k", wants to change he`s info such as Age and Weight.
I have made a function that queries the database, and it manages to reach the "AdditionalUserInfo" table which is good. But the next task is to reach those specific values that belong to the logged-in user.
here is the code:
public class UserSettingsActivity extends AppCompatActivity {
private Button mEditInfoButton;
private TextView usernameField;
private EditText ageField, weightField;
private DatabaseReference dbUsernames;
DatabaseReference the_additional_userInfo_table = FirebaseDatabase.getInstance().getReference("AdditionalUserInfo");
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user_settings);
ageField = (EditText) findViewById(R.id.ageID);
weightField = (EditText) findViewById(R.id.weightID);
mEditInfoButton = (Button) findViewById(R.id.editButton);
usernameField = (TextView) findViewById(R.id.usernameTextViewID);
mEditInfoButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
QueryUserInfo();
}
});
}
public void QueryUserInfo(){
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference the_additional_userInfo_table = database.getReference("AdditionalUserInfo");
//Query query =the_additional_userInfo_table.child("username");
the_additional_userInfo_table.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
Toast.makeText(UserSettingsActivity.this, "User exists!", Toast.LENGTH_SHORT).show();
// dataSnapshot is the "issue" node with all children with id 0
for (DataSnapshot issue : dataSnapshot.getChildren()) {
// do something with the individual "issues"
}
if(!dataSnapshot.exists()){
Toast.makeText(UserSettingsActivity.this, "nooooo user!", Toast.LENGTH_SHORT).show();
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}

To get the data under AdditionalUserInfo that corresponds to a specific user, you need to use a query that looks like this:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference additionalUserInfoRef = rootRef.child("AdditionalUserInfo");
Query userQuery = additionalUserInfoRef.orderByChild("username").equalTo("Raxor2k");
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
Map<String, Object> map = new HashMap<>();
map.put("user-age", "30");
map.put("user-weight", "30");
ds.getRef().updateChildren(map);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Log.d(TAG, databaseError.getMessage()); //Don't ignore errors!
}
};
userQuery.addListenerForSingleValueEvent(valueEventListener);
The result in your database will be the change of both properties from 25 to 30. Since you didn't add the database as a text, file I have used in the query he user name but a more elegant way of querying the database would be to use the uid.
Query userQuery = additionalUserInfoRef.orderByChild("user-id").equalTo("IXL ... Eoj");

Java ValueEventListener infinite loop

I am having trouble with my Firebase code to add a contact to a user profile. This exact code used to work fine, and now as of today it gets itself into an infinite loop and creates contacts repeatedly until I force kill the application. I can't work out where the loop is, or what may have changed!
Code:
public class AddContacts extends AppCompatActivity {
private EditText addContactNumber;
private Button btnAddContact;
private String userResult, searchPhone, ping_userID;
private FirebaseAuth pingAuth;
DatabaseReference ref;
private FirebaseAuth.AuthStateListener pingAuthListener;
addContactNumber = (EditText) findViewById(R.id.addContactNumber);
btnAddContact = (Button) findViewById(R.id.btnAddContact);
btnAddContact.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
searchPhone = addContactNumber.getText().toString();
ref = FirebaseDatabase.getInstance().getReference().child("Profiles");
ref.orderByChild("Phone").equalTo(searchPhone).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot datas : dataSnapshot.getChildren()) {
userResult = datas.getKey();
if (userResult != null) {
ping_userID = pingAuth.getCurrentUser().getUid();
DatabaseReference newContact = FirebaseDatabase.getInstance().getReference().child("Profiles").child(ping_userID).child("Contacts");
newContact.setValue(userResult);
DatabaseReference newContactPing = FirebaseDatabase.getInstance().getReference().child("Profiles").child(ping_userID).child("Contacts").child(userResult).child("PingStatus");
newContactPing.setValue(false);
DatabaseReference addRef = FirebaseDatabase.getInstance().getReference().child("Profiles").child(userResult).child("Name");
addRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String resultName = dataSnapshot.getValue(String.class);
DatabaseReference addContactName = FirebaseDatabase.getInstance().getReference().child("Profiles").child(ping_userID).child("Contacts").child(userResult).child("Name");
addContactName.setValue(resultName);
Toast.makeText(getBaseContext(), "User: " + resultName + " added successfully.", Toast.LENGTH_SHORT).show();
ref.removeEventListener(this);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
} else {
Toast.makeText(getBaseContext(), "User not found.", Toast.LENGTH_SHORT).show();
ref.removeEventListener(this);
break;
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
});
}
Also, perhaps as an aside, it never triggers the "User not found" event, even if I enter details that are not in the database.
Any ideas? I am sure it is staring me in the face but I don't see it.
#Peter Haddad Database as requested:
MyAppDatabase
-Profiles
-BCsuC4XAZqVhWj
-Name: "Simon"
-Phone: 123456
-Contacts
-pnYn1NhzzNQAm
-Name: "Bill"
-PingStatus: false
-pnYn1NhzzNQAm
-Name: "Bill"
-Phone: 987654
-Contacts
-BCsuC4XAZqVhWj
-Name: "Simon"
-PingStatus: false

Use addListenerForSingleValueEvent instead of addValueEventListener in both the cases.

Get specific value from Firebase

I have this firebase database:
That has been created with this code:
private DatabaseReference mDatabase;
private EditText tbfirstname;
private EditText tblastname;
private EditText tbemail;
private Button btnSubmit;
private String str_firstname;
private String str_lastname;
private String str_email;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mDatabase = FirebaseDatabase.getInstance().getReference().child("Users");
//GUI DECLARATIONS
tbfirstname = (EditText) findViewById(R.id.tb_firstname);
tblastname = (EditText) findViewById(R.id.tb_lastname);
tbemail = (EditText) findViewById(R.id.tb_email);
btnSubmit = (Button) findViewById(R.id.btn_register);
btnSubmit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//HANDLES VALUES FROM TB TO STR
str_firstname = tbfirstname.getText().toString().trim();
str_lastname = tblastname.getText().toString().trim();
str_email = tbemail.getText().toString().trim();
HashMap<String, String> dataMap = new HashMap<String, String>();
dataMap.put("Firstname", str_firstname);
dataMap.put("Lastname", str_lastname);
dataMap.put("Email", str_email);
mDatabase.push().setValue(dataMap).addOnCompleteListener(new OnCompleteListener<Void>() {
#Override
public void onComplete(#NonNull Task<Void> task) {
if(task.isSuccessful()){
Toast.makeText(MainActivity.this,"Registered Successfully!",Toast.LENGTH_LONG).show();
tbfirstname.setText("");
tblastname.setText("");
tbemail.setText("");
} else {
Toast.makeText(MainActivity.this, "There was an Error. Try Again!", Toast.LENGTH_LONG).show();
}
}
});
}
});
}
It's actually a simple app that let users register some data. What I wanna do is I want to create a search textboxthat will locate specific data in the database based on what the user has entered in that textbox and returns a value.
For example I'll search steve#sample.com, if there is an email in the database that has the same value, I want it to return its root value namely L4JyRA77YKldmMWM-C7. If somehow there is no said record, I want it to return with false or something.
Requirements:I'm really a beginner in Android and Firebase so if you could make the code newbie-friendly, that'll really be a great help. Thanks!

first of all you need to fetch all records from firebase database List<User>
create copy of list List<User> temp = new ArrayList();
you can add particular searchable user detail in temp - temp.add(users.get(i));
Now you can get useremail like this email = temp.get(i).getEmailId();
FirebaseDatabase.getInstance().getReference().child("Your table name").orderByChild("email").equalTo(your searchable emailid ).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
Iterator<DataSnapshot> dataSnapshots = dataSnapshot.getChildren().iterator();
List<User> users = new ArrayList<>();
while (dataSnapshots.hasNext()) {
DataSnapshot dataSnapshotChild = dataSnapshots.next();
User user = dataSnapshotChild.getValue(User.class);
users.add(user);
}
String userids = "";
List<User> temp = new ArrayList();
try {
for (int i = 0; i < users.size(); i++) {
if (users.get(i).getEmailid().equals("your searchable email")) {
temp.add(users.get(i));
//Here you can find your searchable user
Log.e("temp", "+" + temp.get(i).getFirebaseId());
email = temp.get(i).getEmailId();
}
}
} catch (Exception e) {
e.printStackTrace();
Log.e("Logs", e.toString());
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});

DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
Query query = reference.child("Users").orderByChild("Email").equalTo("editext.getText()");
query.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
// dataSnapshot is the "issue" node with all children with id 0
for (DataSnapshot issue : dataSnapshot.getChildren()) {
// do something with the individual "issues"
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
Some general things to remember is never name nodes with Capital letters

Android App crashes when trying to store 3 strings from a child on a Firebase database when trying to read strings. No Authentication yet

I've already set up Firebase with the app using Tools -> Firebase and added the internet access to manifest.
I'm trying to just get the strings from the child to be saved on the app so I can use them later on when I develop it further. I dont care about authentication yet so userID process is irrelevant as far as I gathered. The first part of the main file has the writing side and when everything else is commented out the app runs and works fine. So the problem is with reading.
What the Firebase Database looks like right now
// MainActivity.java:
public class MainActivity extends AppCompatActivity {
private DatabaseReference mDatabase;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mDatabase = FirebaseDatabase.getInstance().getReference("Strings");
Button sendBtn = (Button) findViewById(R.id.sendBtn);
EditText stringText = (EditText) findViewById(R.id.stringText);
TextView textView = (TextView) findViewById(R.id.textView);
sendBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("message");
myRef.setValue("I can send text to this from Android App");
}
});
mDatabase.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
showData(dataSnapshot);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
private void showData(DataSnapshot dataSnapshot) {
StringExchange stringX = new StringExchange();
stringX.setPhoneNum(dataSnapshot.getValue(StringExchange.class).getPhoneNum());
stringX.setTrapID(dataSnapshot.getValue(StringExchange.class).getTrapID());
stringX.setActive(dataSnapshot.getValue(StringExchange.class).getActive());
Toast.makeText(getBaseContext(), "Strings Saved", Toast.LENGTH_SHORT).show();
}
}
// class: StringExchange.java:
package com.snaresense.firebase;
/**
* Created by Kevin on 10/21/2017.
*/
public class StringExchange {
String PhoneNum;
String Active;
String TrapID;
public StringExchange(){
}
public String getPhoneNum(){
return PhoneNum;
}
public void setPhoneNum(String PhoneNum){
this.PhoneNum = PhoneNum;
}
public String getActive(){
return Active;
}
public void setActive(String Active){
this.Active = Active;
}
public String getTrapID(){
return TrapID;
}
public void setTrapID(String TrapID){
this.TrapID = TrapID;
}
}

#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DatabaseReference ref = FirebaseDatabase.getInstance().getReference();
ref.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String Active = dataSnapshot.child("snaresense").child("strings").child("StringActive").getValue(String.class);
String BatteryLevel = dataSnapshot.child("snaresense").child("strings").child("StringBatteryLevel").getValue(String.class);
String TrapId = dataSnapshot.child("snaresense").child("strings").child("StringTrapId").getValue(String.class);
String fireData = ("Hello. Trap: "+TrapId+" has been activated. The battery level is: "+BatteryLevel);
String usrnum = dataSnapshot.child("snaresense").child("strings").child("StringPhoneNum").getValue(String.class);
sendMsg (usrnum, fireData);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
The reading part works and the sendMsg part is just for sending text messages with the final app.

Your showData function is bit messed up. Try changing it to:
private void showData(DataSnapshot dataSnapshot) {
StringExchange stringX = dataSnapshot.getValue(StringExchange.class);
Toast.makeText(this, "Strings Saved", Toast.LENGTH_SHORT).show();
}
If it still doesn't work, please elaborate what is the exact problem? Is it crashing? If yes then share the log. If its not working as expected then explain whats not working.