RecyclerView does not update after add data - android-recyclerview

Question

I'm migrating from ListView to RecyclerView, but after entering some data in SQLite, my list is not updated using notifyDataSetChanged (); so I always have to call the setAdapter () method;
I have simplified my code to post here. can anyone help me fix the notifyDataSetChanged (); to work in my code please?
RecyclerViewAdapter
public class RecyclerViewAdapter extends RecyclerView.Adapter<ViewHolder> {
private List<Model> model;
private Context context;
public RecyclerViewAdapter(Context context, List<Model> model) {
this.context = context;
this.model = new ArrayList<>(model);
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.custom_layout, parent, false);
return new ViewHolder(context, view, model);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
final Model model = model.get(position);
holder.bind(model);
}
#Override
public int getItemCount() {
return model.size();
} }
ViewHolder
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private List<Model> model = new ArrayList<>();
private Context context;
private TextView textViewGroup;
private TextView textViewName;
public ViewHolder(Context context, View itemView, List<Model> model) {
super(itemView);
this.model = model;
this.context = context;
itemView.setOnClickListener(this);
textViewGroup = (TextView) itemView.findViewById(R.id.textViewGroup);
textViewName = (TextView) itemView.findViewById(R.id.textViewName);
}
public void bind(Model model) {
textViewGroup.setText(model.getGroup());
textViewName.setText(model.getName());
}
}
#Override
public void onClick(View view) {
Model model = this.model.get(getAdapterPosition());
Intent intent = new Intent(this.context, ShowGroup.class);
intent.putExtra("DATA", model);
intent.putExtra("POSITION", getAdapterPosition());
((Activity) this.context).startActivityForResult(intent, 7);
Log.i(">>", "_IDHOLDER: " + model.getId());
Log.i(">>", "_POSITION: " + getAdapterPosition());
Log.i(">>", ".");
} }
Model
public class Model implements Serializable {
public static final String TABLE = "GROUP_NAME";
public static final String ID = "_ID";
public static final String GROUP = "GROUP";
public static final String NAME = "NAME";
private long id;
private String group;
private String name;
public Model() {
setId(0);
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getGroup() {
return group;
}
public void setGroup(String group) {
this.group = group;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
} }
Repository
public class Repository {
private SQLiteDatabase db;
public Repository(SQLiteDatabase db) {
this.db = db;
}
private ContentValues fillModelValues(Model model) {
ContentValues values = new ContentValues();
values.put(Model.GROUP, model.getGroup());
values.put(Model.NAME, model.getName());
return values;
}
public void insert(Model model) {
ContentValues values = fillModelValues(model);
db.insertOrThrow(Model.TABLE, null, values);
}
public List<Model> consDataBase(Context context) {
List<Model> listModel = new ArrayList<>();
Cursor cursor = db.query(Model.TABLE, null, null, null, null, null, null);
if (cursor.getCount() > 0) {
cursor.moveToFirst();
do {
Model model = new Model();
model.setId(cursor.getLong(cursor.getColumnIndex(Model.ID)));
model.setGroup(cursor.getString(cursor.getColumnIndex(Model.GROUP)));
model.setName(cursor.getString(cursor.getColumnIndex(Model.NAME)));
listModel.add(model);
} while (cursor.moveToNext());
}
cursor.close();
return listModel;
} }
MainActivity
public class MainActivity extends AppCompatActivity {
private List<Model> listModel;
private LinearLayoutManager layoutManager;
private RecyclerView recyclerView;
private RecyclerViewAdapter recyclerViewAdapter;
private FloatingActionButton fab;
private DataBase dataBase;
private SQLiteDatabase db;
private Repository repository;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
layoutManager = new LinearLayoutManager(this);
recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(layoutManager);
fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startActivityForResult(new Intent(MainActivity.this, AddGroup.class), 4);
}
});
try {
dataBase = new DataBase(this);
db = dataBase.getWritableDatabase();
repository = new Repository(db);
listModel = repository.consDataBase(context);
recyclerViewAdapter = new RecyclerViewAdapter(context, listModel);
recyclerView.setAdapter(recyclerViewAdapter);
recyclerView.setHasFixedSize(true);
} catch (SQLException e) {
}
}
#Override
protected void onDestroy() {
super.onDestroy();
if (db != null) {
db.close();
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 4) {
listModel = repository.consDataBase(context);
recyclerViewAdapter = new RecyclerViewAdapter(context, listModel);
recyclerView.setAdapter(recyclerViewAdapter);
}
} }
AddGroup
public class AddGroup extends AppCompatActivity {
private EditText editTextGroup;
private EditText editTextName;
private DataBase dataBase;
private SQLiteDatabase db;
private Repository repository;
private Model model;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_group);
editTextGroup = (EditText) findViewById(R.id.editTextGroup);
editTextName = (EditText) findViewById(R.id.editTextName);
try {
dataBase = new DataBase(this);
db = dataBase.getWritableDatabase();
repository = new Repository(db);
model = new Model();
} catch (SQLException e) {
}
}
private void saveModel() {
try {
model.setGroup(editTextGroup.getText().toString().trim());
model.setName(editTextName.getText().toString().trim());
if (model.getId() == 0) {
repository.insert(model);
}
} catch (Exception e) {
}
}
#Override
protected void onDestroy() {
super.onDestroy();
if (db != null) {
db.close();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu_add_group, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.action_save) {
saveModel();
}
return super.onOptionsItemSelected(item);
} }

Answer 1

it's working now
RecyclerViewAdapter
public class RecyclerViewAdapter extends RecyclerView.Adapter<ViewHolder> {
private List<Model> model;
private Context context;
public RecyclerViewAdapter(Context context, List<Model> model) {
this.context = context;
this.model = new ArrayList<>(model);
}
...
public void notify(List<Model> list) {
if (model != null) {
model.clear();
model.addAll(list);
} else {
model = list;
}
notifyDataSetChanged();
}
}
Then in onActivityResult
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 4) {
listModel = repository.consDataBase(this);
recyclerViewAdapter.notify(listModel);
}
}
thank you :)

Answer 2

In order to have your code working you need to change Adapter constructor implementation as follows:
public RecyclerViewAdapter(Context context, List<Model> model) {
this.context = context;
this.model = model;
}
Then in onActivityResult do like this:
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == 4) {
listModel.clear();
listModel.addAll(repository.consDataBase(context));
recyclerViewAdapter.notifyDataSetChanged();
}
}

Answer 3

Simply put:
RecyclerViewAdapter.notyfyDataSetChanged();