I am building a calendar app but I am having trouble getting the backend to work. I am able to save/delete and edit my events but I can't get them to display when the user clicks into the calendar. The users are able to view their saved data as they make changes on screen but once they restart the app or click to other views everything is gone. I checked my list content and the details are always displayed as null.
public class CalendarViewWithNotesActivitySDK21_v2 extends Fragment {
private final static int CREATE_EVENT_REQUEST_CODE = 100;
private String[] mShortMonths;
private CalendarView mCalendarView;
private CalendarDialog mCalendarDialog;
private List<CalenderEventModel> mEventList = new ArrayList<>();
private static Context context = null;
public static Intent makeIntent(Context context) {
return new Intent(context, CalendarViewWithNotesActivitySDK21_v2.class);
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
context = getActivity();
setHasOptionsMenu(true);
View v = inflater.inflate(R.layout.activity_calendar_view_with_notes_sdk_21, container, false);
//getFirebaseData();
//mShortMonths = new DateFormatSymbols().getShortMonths();
initializeUI(v);
return v;
}
private void getFirebaseData() {
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
assert user != null;
final String uid = user.getUid();
final FirebaseDatabase db = FirebaseDatabase.getInstance();
final DatabaseReference ref = db.getReference("Calendar Events").child(uid);
ref.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
mEventList.clear();
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String id = ds.getKey();
String title = ds.child("title").getValue(String.class);
Calendar date = ds.child("date").getValue();
int color = ds.child("color").getValue(Integer.class);
boolean complete = ds.child("completed").getValue(boolean.class);
CalenderEventModel model = new CalenderEventModel(id,title,date,color,complete);
mEventList.add(model);
//mEventList.add(ds.getValue(CalenderEventModel.class));
}
}
@Override
public void onCancelled(@NonNull DatabaseError databaseError) {
}
});
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getFirebaseData();
mShortMonths = new DateFormatSymbols().getShortMonths();
//initializeUI();
}
This is how i save to firebase
private void save() {
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
assert user != null;
final String uid = user.getUid();
final FirebaseDatabase database = FirebaseDatabase.getInstance();
final DatabaseReference ref = database.getReference("Calendar Events").child(uid);
String key = ref.push().getKey();
int action = mOriginalEvent != null ? ACTION_EDIT : ACTION_CREATE;
String id = mOriginalEvent != null ? mOriginalEvent.getID() : key;
String rawTitle = mTitleView.getText().toString().trim();
if(mOriginalEvent == null) {
mOriginalEvent = new CalenderEventModel(
id,
rawTitle.isEmpty() ? null : rawTitle,
mCalendar,
mColor,
mIsCompleteCheckBox.isChecked()
);
Map<String, Object> childUpdate = new HashMap<>();
childUpdate.put(key, mOriginalEvent.toFirebaseObject());
ref.updateChildren(childUpdate, new DatabaseReference.CompletionListener() {
@Override
public void onComplete(@Nullable DatabaseError databaseError, @NonNull DatabaseReference databaseReference) {
if (databaseError == null) {
return;
}
}
});
} else {
mOriginalEvent.setmTitle(rawTitle.isEmpty() ? null : rawTitle);
mOriginalEvent.setmDate(mCalendar);
mOriginalEvent.setmColor(mColor);
mOriginalEvent.setCompleted(mIsCompleteCheckBox.isChecked());
ref.child(mOriginalEvent.getID()).setValue(mOriginalEvent);
}
setResult(RESULT_OK, new Intent()
.putExtra(INTENT_EXTRA_ACTION, action)
.putExtra(INTENT_EXTRA_EVENT, mOriginalEvent));
finish();
if (action == ACTION_CREATE)
overridePendingTransition(R.anim.stay, R.anim.slide_out_down);
}
This is my event modal class
public class CalenderEventModel implements Parcelable {
private String mID;
private String mTitle;
private Calendar mDate;
private int mColor;
private boolean isCompleted;
public CalenderEventModel() {
}
public CalenderEventModel(String id, String title, Calendar date, int color, boolean isCompleted) {
mID = id;
mTitle = title;
mDate = date;
mColor = color;
this.isCompleted = isCompleted;
}
public void setmID(String mID) {
this.mID = mID;
}
public void setmTitle(String mTitle) {
this.mTitle = mTitle;
}
public void setmDate(Calendar mDate) {
this.mDate = mDate;
}
public void setmColor(int mColor) {
this.mColor = mColor;
}
public void setCompleted(boolean completed) {
isCompleted = completed;
}
public String getID() {
return mID;
}
public String getTitle() {
return mTitle;
}
public Calendar getDate() {
return mDate;
}
public int getColor() {
return mColor;
}
public boolean isCompleted() {
return isCompleted;
}
public Map<String, Object> toFirebaseObject() {
HashMap<String, Object> event = new HashMap<>();
event.put("mid", mID);
event.put("title", mTitle);
event.put("date", mDate);
event.put("color", mColor);
event.put("completed", isCompleted);
return event;
}
protected CalenderEventModel(Parcel in) {
mID = in.readString();
mTitle = in.readString();
mColor = in.readInt();
mDate = (Calendar) in.readSerializable();
isCompleted = in.readByte() != 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(mID);
dest.writeString(mTitle);
dest.writeInt(mColor);
dest.writeSerializable(mDate);
dest.writeByte((byte) (isCompleted ? 1 : 0));
}
@Override
public int describeContents() {
return 0;
}
public static final Creator<CalenderEventModel> CREATOR = new Creator<CalenderEventModel>() {
@Override
public CalenderEventModel createFromParcel(Parcel in) {
return new CalenderEventModel(in);
}
@Override
public CalenderEventModel[] newArray(int size) {
return new CalenderEventModel[size];
}
};
}
In the method to get firebase data, i tried getting the data one by one as seen in the uncommented out statement but i face this error
java.lang.ClassCastException: java.util.HashMap cannot be cast to java.util.Calendar
at com.example.serenity.CalendarViewWithNotesActivitySDK21_v2$1.onDataChange(CalendarViewWithNotesActivitySDK21_v2.java:91)
at com.google.firebase.database.core.ValueEventRegistration.fireEvent(com.google.firebase:firebase-database@@19.3.0:75)
at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@19.3.0:63)
at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@19.3.0:55)
at android.os.Handler.handleCallback(Handler.java:907)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7478)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:549)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941)
