Using Firebase Auth to Authenticate Users

Author: dragosholban

.idea/caches/build_file_checksums.ser

@@ -25,7 +25,8 @@ dependencies {
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'
     androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
-    compile 'com.google.firebase:firebase-core:15.0.0'
+    implementation 'com.google.firebase:firebase-core:15.0.0'
+    implementation 'com.firebaseui:firebase-ui-auth:3.3.1'
 }
 
 apply plugin: 'com.google.gms.google-services'

app/build.gradle

@@ -1,13 +1,50 @@
 package com.dragosholban.myinstagramapp;
 
+import android.content.Intent;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.view.View;
+import android.widget.Toast;
+
+import com.firebase.ui.auth.AuthUI;
+import com.firebase.ui.auth.IdpResponse;
+import com.google.firebase.auth.FirebaseAuth;
+import com.google.firebase.auth.FirebaseUser;
 
 public class MainActivity extends AppCompatActivity {
 
+    private static final int RC_SIGN_IN = 123;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
     }
+
+    public void signIn(View view) {
+        startActivityForResult(
+                // Get an instance of AuthUI based on the default app
+                AuthUI.getInstance().createSignInIntentBuilder().build(),
+                RC_SIGN_IN);
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+
+        if (requestCode == RC_SIGN_IN) {
+            IdpResponse response = IdpResponse.fromResultIntent(data);
+
+            if (resultCode == RESULT_OK) {
+                // Successfully signed in
+                FirebaseUser fbUser = FirebaseAuth.getInstance().getCurrentUser();
+                Toast.makeText(this, "Authenticated as " + fbUser.getDisplayName(), Toast.LENGTH_SHORT).show();
+            } else {
+                // Sign in failed, check response for error code
+                if (response != null) {
+                    Toast.makeText(this, response.getError().getMessage(), Toast.LENGTH_SHORT).show();
+                }
+            }
+        }
+    }
 }

app/src/main/java/com/dragosholban/myinstagramapp/MainActivity.java

@@ -6,13 +6,14 @@
     android:layout_height="match_parent"
     tools:context=".MainActivity">
 
-    <TextView
+    <Button
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:text="Hello World!"
+        android:text="Sign In"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintLeft_toLeftOf="parent"
         app:layout_constraintRight_toRightOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        app:layout_constraintTop_toTopOf="parent"
+        android:onClick="signIn"/>
 
 </android.support.constraint.ConstraintLayout>