如何检测用户是否首次在Firebase中

Question

我需要检查用户是否是首次登录，如果是，则使用其他属性（积分，会员资格等）初始化其帐户。

可以让用户更改其设备并希望再次在另一台设备上登录。

我正在使用Google登录方法。我尝试过这样的事情。

if(FirebaseAuth.getInstance().getCurrentUser() != null){
                           Toast.makeText(Anamain.this, "Welcome again xyz", Toast.LENGTH_SHORT).show();
                       }

我使用新帐户登录，所以是第一次使用此应用程序登录，但无论如何仍显示“ Welcome again xyz”消息。

如何检测以前用户是否存在于数据库中？

完整代码

package com.mertg.testsignin;

import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;


import com.google.android.gms.auth.api.Auth;
import com.google.android.gms.auth.api.signin.GoogleSignIn;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.gms.auth.api.signin.GoogleSignInClient;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.common.ConnectionResult;

import com.google.android.gms.common.SignInButton;
import com.google.android.gms.common.api.ApiException;
import com.google.android.gms.common.api.CommonStatusCodes;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.auth.GoogleAuthProvider;
import com.google.firebase.database.FirebaseDatabase;


public class Anamain extends AppCompatActivity {


    private String TAG = "Anamain";
    private SignInButton signIn;
    GoogleSignInClient mGoogleSignInClient;
    private int RC_SIGN_IN = 1;
    private FirebaseAuth mAuth;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_anamain);

        signIn = (SignInButton)findViewById(R.id.googleBtn);

        mAuth = FirebaseAuth.getInstance();

        // Configure sign-in to request the user's ID, email address, and basic
// profile. ID and basic profile are included in DEFAULT_SIGN_IN.
        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestIdToken(getString(R.string.default_web_client_id))
                .requestEmail()
                .build();

        mGoogleSignInClient = GoogleSignIn.getClient(this, gso);

        signIn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                signIn();
            }
        });


    }

    private void signIn() {
        Intent signInIntent = mGoogleSignInClient.getSignInIntent();
        startActivityForResult(signInIntent, RC_SIGN_IN);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...);
        if (requestCode == RC_SIGN_IN) {
            Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
            try {
                // Google Sign In was successful, authenticate with Firebase
                GoogleSignInAccount account = task.getResult(ApiException.class);
                firebaseAuthWithGoogle(account);

            } catch (ApiException e) {
                // Google Sign In failed, update UI appropriately
                Log.w(TAG, "Google sign in failed", e);


                // ...
            }
        }
    }



    private void firebaseAuthWithGoogle(GoogleSignInAccount acct) {
        Log.d("TAG", "signInWithCredential:success" + acct.getId());

        AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);
        mAuth.signInWithCredential(credential)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                       /* if (!task.isSuccessful()){
                        Log.d("TAG", "signInWithCredential:success");
                        FirebaseUser user = mAuth.getCurrentUser();
                            updateUI(user);
                        }*/
                       if(FirebaseAuth.getInstance().getCurrentUser() != null){
                           Toast.makeText(Anamain.this, "Welcome again xyz", Toast.LENGTH_SHORT).show();
                       }

                       else {
                            //Log.w("TAG", "signInWithCredential:failure", task.getException());
                           // Toast.makeText(Anamain.this, "Basaramadim", Toast.LENGTH_SHORT).show();
                            //updateUI(null);
                           Toast.makeText(Anamain.this, "Register Successful", Toast.LENGTH_SHORT).show();
                           FirebaseUser user = mAuth.getCurrentUser();
                           //updateUI(user);
                        }

                    }


                });

    }

    private void updateUI(FirebaseUser user) {
        GoogleSignInAccount acct = GoogleSignIn.getLastSignedInAccount(getApplicationContext());
        if(acct != null)    {
            String personName = acct.getDisplayName();

            Toast.makeText(this, "Sen Girdin" + personName, Toast.LENGTH_SHORT).show();
        }
    }

}

更新

我得到错误：';'该行应有

mAuth.signInWithCredential(credential)

这是替换方式

private void firebaseAuthWithGoogle(GoogleSignInAccount acct) {
        Log.d("TAG", "signInWithCredential:success" + acct.getId());

        AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);
        mAuth.signInWithCredential(authCredential).addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
            @Override
            public void onComplete(@NonNull Task<AuthResult> task) {
                boolean isNewUser = task.getResult().getAdditionalUserInfo().isNewUser();
                if (isNewUser) {
                    Log.d(TAG, "Is New User!");
                } else {
                    Log.d(TAG, "Is Old User!");
                }
            }

        });

    }

Answer 1

  

如何检测用户是否是首次使用Firebase？

如果您要检查用户是否首次登录，则检查用户是否是新用户也是一样。因此，要解决此问题，您只需调用AdditionalUserInfo的isNewUser()方法：

  

返回用户是新用户还是现有用户

在OnCompleteListener.onComplete回调中，如下所示：

OnCompleteListener<AuthResult> completeListener = new OnCompleteListener<AuthResult>() {
    @Override
    public void onComplete(@NonNull Task<AuthResult> task) {
        if (task.isSuccessful()) {
            boolean isNewUser = task.getResult().getAdditionalUserInfo().isNewUser();
            if (isNewUser) {
                Log.d("TAG", "Is New User!");
            } else {
                Log.d("TAG", "Is Old User!");
            }
        }
    }
};

有关更多信息，请参见official documentation。

编辑：为了使其正常工作，您需要添加完整的侦听器。请参见下面的代码：

mAuth.signInWithCredential(credential).addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
    @Override
    public void onComplete(@NonNull Task<AuthResult> task) {
        boolean isNewUser = task.getResult().getAdditionalUserInfo().isNewUser();
        if (isNewUser) {
            Log.d(TAG, "Is New User!");
        } else {
            Log.d(TAG, "Is Old User!");
        }
    }
});

或更简单：

mAuth.signInWithCredential(credential).addOnCompleteListener(this, completeListener);

其中completeListener对象是首先定义的对象。

Answer 2

您可以在数据库中拥有user node，可以在其中添加key作为uuid，并将值添加为其唯一的uuid，如果您的用户是首次访问，您将无法在用户节点上获得uuid，因此您可以在数据库中初始化用户时在其中添加uuid

Answer 3

在数据库中创建isFirstTime = false类型的标志。首次安装该应用程序时，将其设置为true。

Answer 4

仅分享我在新用户问题上的先前实现。

我在项目中使用了 Firebase Cloud Firestore ，所以我创建了另一个表来存储用户的基本信息。

首先，我创建一个名为createUser()的方法，但是基本上，它通过查询Firebase Cloud Firestore数据库来检查它是否是首次使用。如果不存在，请为该用户创建一个文档，然后您可以对他们执行操作，在下面的代码中查找//you can add some action here。

下面是我上一个项目的实际代码，其中包括一个基于角色的管理来控制用户访问权限（如果您感兴趣，请参考）。

 public void createUser(){
        docRef = mFirestore.collection("users").document(auth.getCurrentUser().getUid());
        docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
            @Override
            public void onComplete(@NonNull Task<DocumentSnapshot> task) {
                if (task.isSuccessful()) {
                    DocumentSnapshot document = task.getResult();

                   //if the user is already in the database, check the user role
                    if (document != null && document.exists()) {
                        User user = document.toObject(User.class);
                        if(user.getRoles().get("admin")==true){
                            Log.d(TAG, "Admin: true");
                            btn_admin.setVisibility(View.VISIBLE);
                        }

                        else{
                            Log.d(TAG, "Admin: false");
                            btn_admin.setVisibility(View.GONE);
                        }

                        Log.d(TAG, "DocumentSnapshot data: " + document.getData());
                    } else {
                         //check whether it's a new user
                         //if yes, create a new document containing the user details thru my User model

                        Log.d(TAG, "No such document");
                        btn_admin.setVisibility(View.GONE);
                        Map<String, Boolean> roles = new HashMap<>();
                        roles.put("editor", false);
                        roles.put("viewer", false);
                        roles.put("admin", false);
                        User user = new User(auth.getCurrentUser().getDisplayName(), auth.getCurrentUser().getUid(),auth.getCurrentUser().getEmail(), roles);
                        //you can add some action here

                        mFirestore.collection("users").document(auth.getCurrentUser().getUid())
                                .set(user, SetOptions.merge())
                                .addOnSuccessListener(new OnSuccessListener<Void>() {
                                    @Override
                                    public void onSuccess(Void aVoid) {
                                        Log.d(TAG, "DocumentSnapshot successfully written!");
                                    }
                                })
                                .addOnFailureListener(new OnFailureListener() {
                                    @Override
                                    public void onFailure(@NonNull Exception e) {
                                        Log.w(TAG, "Error writing document", e);
                                    }
                                });
                        //Log.d(TAG, "Created credential");
                    }
                } else {
                    Log.d(TAG, "get failed with ", task.getException());
                }
            }
        });
    }