geoquiz-parse: A Java repository from joshskeen

Geoquiz is back, with a snazzy Parse backend for sharing quiz questions with world!

##setup

https://www.parse.com/signup - create an account
create a new app at https://www.parse.com/apps
visit the "Keys" section of the app you just created. Copy the Application ID & Client Key
Parse libraries need to be added next. Unfortunately they're not officially available in maven central, but we can work around that using jitpack.io, a new competitor to maven central that makes it a snap to make libraries distributable.

build.gradle :

	allprojects {
	    repositories {
	        jcenter()
	        maven {
	            url "https://jitpack.io"
	        }
	    }
	}

app/build.gradle :

dependencies {
    compile 'com.android.support:appcompat-v7:22.1.0'
    //load dependency from jitpack
    compile 'com.github.yongjhih:parse:1.9.2'
    compile 'com.github.yongjhih:parse-crash-reporting:1.9.2'
    compile 'com.github.yongjhih:parse-facebook-v3:1.9.2'
    compile 'com.facebook.android:facebook-android-sdk:3.20.0'
    compile 'com.parse.bolts:bolts-android:1.1.4'
}

Create a subclass of Application :


public class GeoquizApplication extends Application {

    //app id and key from Parse
    public static final String YOUR_APPLICATION_ID = "your app ud";
    public static final String YOUR_CLIENT_KEY = "your client key";

    @Override
    public void onCreate() {
        super.onCreate();
        ParseCrashReporting.enable(this);
        Parse.enableLocalDatastore(this);
        Parse.initialize(this, YOUR_APPLICATION_ID, YOUR_CLIENT_KEY);
        ParseUser.enableAutomaticUser();
        QuizQuestionManager.registerParseObjects();
    }
}

Note QuizQuestionManager - it's new class we'll create to manage interacting with our Parse-backed quiz questions.

change your manifest to refer to the GeoquizApplication:

    <application
    android:name=".GeoquizApplication"
    ...

We'll build our question models as a subclass of ParseObject, which will imbue the object with special methods that let us write to the cloud. ParseQuizQuestion.java:

@ParseClassName("ParseQuizQuestion")
public class ParseQuizQuestion extends ParseObject {
    public static final String MODEL_NAME = "ParseQuizQuestion";

    public ParseQuizQuestion() {
    }

    public String getQuestionText() {
        return getString(QUESTION_FIELD_KEY);
    }

    public void setQuestion(String question) {
        put(QUESTION_FIELD_KEY, question);
    }

    public boolean isAnswerTrue() {
        return getBoolean(ANSWER_IS_TRUE);
    }

    public void setIsAnswerTrue(boolean isTrue) {
        put(ANSWER_IS_TRUE, isTrue);
    }

    @Override
    public String toString() {
        return "ParseQuizQuestion{" + getQuestionText() + ", }";
    }
}

QuizQuestionManager will be responsible for creating and loading ParseQuizQuestion objects in the cloud.

QuizQuestionManager.java:

public class QuizQuestionManager {

    public static void registerParseObjects() {
        ParseObject.registerSubclass(ParseQuizQuestion.class);
    }

    public void addQuestion(String question, boolean isTrue, final QuizAddedCallback quizAddedCallback) {
        ParseQuizQuestion parseQuizQuestion = new ParseQuizQuestion();
        parseQuizQuestion.setQuestion(question);
        parseQuizQuestion.setIsAnswerTrue(isTrue);

        parseQuizQuestion.saveInBackground(new SaveCallback() {
            @Override
            public void done(ParseException e) {
                quizAddedCallback.onQuizAdded();
            }
        });
    }

    public void loadQuestions(final QuizLoadedCallback callback) {
        ParseQuery<ParseQuizQuestion> query = new ParseQuery<>(ParseQuizQuestion.MODEL_NAME);
        query.findInBackground(new FindCallback<ParseQuizQuestion>() {
            @Override
            public void done(List<ParseQuizQuestion> list, ParseException e) {
                callback.onQuestionsLoaded(list);
            }
        });
    }
}

Since the saveInBackground & findInBackground methods are asynchronous, we will use callbacks interfaces that point to the calling activity to find out when they complete.

public interface QuizLoadedCallback {
    void onQuestionsLoaded(List<ParseQuizQuestion> questions);
}

public interface QuizAddedCallback {
    void onQuizAdded();
}

This is an overview of what's involved. You'll still need to wire up a new activity for creating a Quiz item and replace your QuestionBank with a list of ParseQuizQuestions..

joshskeen/geoquiz-parse

Geoquiz is back, with a snazzy Parse backend for sharing quiz questions with world!