MainActivity.java

package com.example.nycworkshopexample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;

import com.amazonaws.amplify.generated.graphql.CreateTodoMutation;
import com.amazonaws.amplify.generated.graphql.ListTodosQuery;
import com.amazonaws.amplify.generated.graphql.OnCreateTodoSubscription;
import com.amazonaws.mobile.client.AWSMobileClient;
import com.amazonaws.mobile.client.Callback;
import com.amazonaws.mobile.client.SignInUIOptions;
import com.amazonaws.mobile.client.UserStateDetails;
import com.amazonaws.mobile.config.AWSConfiguration;
import com.amazonaws.mobileconnectors.appsync.AWSAppSyncClient;
import com.amazonaws.mobileconnectors.appsync.AppSyncSubscriptionCall;
import com.amazonaws.mobileconnectors.appsync.fetcher.AppSyncResponseFetchers;
import com.amazonaws.mobileconnectors.appsync.sigv4.CognitoUserPoolsAuthProvider;
import com.apollographql.apollo.GraphQLCall;
import com.apollographql.apollo.api.Response;
import com.apollographql.apollo.exception.ApolloException;
import com.example.nycworkshopexample.R;

import javax.annotation.Nonnull;

import type.CreateTodoInput;

public class MainActivity extends AppCompatActivity {

    // tag for logs
    private static final String TAG = "MainActivity";

    // instance of mobile client
    private final AWSMobileClient CLIENT = AWSMobileClient.getInstance();

    private AWSAppSyncClient mAWSAppSyncClient;

    // used for subscriptions
    private AppSyncSubscriptionCall subscriptionWatcher;

    // query, mutation, and subscription methods and callbacks
    public void query(){
        mAWSAppSyncClient.query(ListTodosQuery.builder().build())
                .responseFetcher(AppSyncResponseFetchers.CACHE_AND_NETWORK)
                .enqueue(todosCallback);
    }

    private GraphQLCall.Callback<ListTodosQuery.Data> todosCallback = new GraphQLCall.Callback<ListTodosQuery.Data>() {
        @Override
        public void onResponse(@Nonnull Response<ListTodosQuery.Data> response) {
            Log.i("API", response.data().listTodos().items().toString());
        }

        @Override
        public void onFailure(@Nonnull ApolloException e) {
            Log.e("ERROR", e.toString());
        }
    };

    public void mutation(){
        CreateTodoInput createTodoInput = CreateTodoInput.builder()
                .name("Use AppSync")
                .description("Realtime and Offline")
                .build();

        mAWSAppSyncClient.mutate(CreateTodoMutation.builder().input(createTodoInput).build())
                .enqueue(mutationCallback);
    }

    private GraphQLCall.Callback<CreateTodoMutation.Data> mutationCallback = new GraphQLCall.Callback<CreateTodoMutation.Data>() {
        @Override
        public void onResponse(@Nonnull Response<CreateTodoMutation.Data> response) {
            Log.i("API", "Added Todo - " + response.data().toString());
        }

        @Override
        public void onFailure(@Nonnull ApolloException e) {
            Log.e("Error", e.toString());
        }
    };

    private void subscribe(){
        OnCreateTodoSubscription subscription = OnCreateTodoSubscription.builder().build();
        subscriptionWatcher = mAWSAppSyncClient.subscribe(subscription);
        subscriptionWatcher.execute(subCallback);
    }

    private AppSyncSubscriptionCall.Callback subCallback = new AppSyncSubscriptionCall.Callback() {
        @Override
        public void onResponse(@Nonnull Response response) {
            Log.i("API SUBSCRIPTION", response.data().toString());
        }

        @Override
        public void onFailure(@Nonnull ApolloException e) {
            Log.e("API SUBSCRIPTION", e.toString());
        }

        @Override
        public void onCompleted() {
            Log.i("API SUBSCRIPTION", "Subscription completed");
        }
    };

    // launches auth UI
    protected void showSignIn() {
        CLIENT.showSignIn(
                this,
                SignInUIOptions.builder()
                        .nextActivity(MainActivity.class)
                        .build(),
                new Callback<UserStateDetails>() {
                    @Override
                    public void onResult(UserStateDetails result) {
                        Log.d(TAG, "onResult: " + result.getUserState());
                        switch (result.getUserState()) {
                            case SIGNED_IN:
                                Log.i("INIT", "logged in!");

                                // create AppSync client
                                mAWSAppSyncClient = AWSAppSyncClient.builder()
                                        .context(getApplicationContext())
                                        .awsConfiguration(new AWSConfiguration(getApplicationContext()))
                                        // add our user pool provider
                                        .cognitoUserPoolsAuthProvider(new CognitoUserPoolsAuthProvider() {
                                            @Override
                                            public String getLatestAuthToken() {
                                                try {
                                                    return CLIENT.getTokens().getIdToken().getTokenString();
                                                } catch (Exception e){
                                                    Log.e("APPSYNC_ERROR", e.getLocalizedMessage());
                                                    return e.getLocalizedMessage();
                                                }
                                            }
                                        }).build();
                                break;
                            case SIGNED_OUT:
                                Log.i(TAG, "onResult: User did not choose to sign-in");
                                break;
                            default:
                                AWSMobileClient.getInstance().signOut();
                                break;
                        }
                    }

                    @Override
                    public void onError(Exception e) {
                        Log.e(TAG, "onError: ", e);
                    }
                }
        );
    }

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

        CLIENT.initialize(getApplicationContext(), new Callback<UserStateDetails>() {
            @Override
            public void onResult(UserStateDetails userStateDetails) {
                switch (userStateDetails.getUserState()) {
                    case SIGNED_IN:
                        Log.d(TAG, "user signed in: " + userStateDetails.getUserState());
                        break;
                    case SIGNED_OUT:
                        showSignIn();
                        break;
                    default:
                        CLIENT.signOut();
                        break;
                }
            }

            @Override
            public void onError(Exception e) {
                Log.e("INIT", "Initialization error.", e);
            }
        });
    }
}