Below you can find a very simple solution for loading contacts using MVVM:
https://github.com/NaarGes/Android-Contact-List
Here comes a bit of code in case the link is no longer working.
First, let's create a simple POJO for contacts UserObject.java
public class UserObject {
private String email, name, phone;
public UserObject() {
// EMPTY CONSTRUCTOR FOR FIREBASE REALTIME DATABASE
}
public UserObject(String email, String name, String phone) {
this.email = email;
this.name = name;
this.phone = phone;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
}
Now, let's create our repository ContactRepository.java
public class ContactRepository {
private Context context;
private static final String TAG = "debinf ContRepo";
public ContactRepository(Context context) {
this.context = context;
}
public List<UserObject> fetchContacts() {
List<UserObject> contacts = new ArrayList<>();
Cursor cursor = context.getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null);
Log.i(TAG, "fetchContacts: cursor.getCount() is "+cursor.getCount());
if ((cursor != null ? cursor.getCount() : 0) > 0) {
while (cursor.moveToNext()) {
String name = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
String phone = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
UserObject contact = new UserObject("",name, phone);
Log.i(TAG, "fetchContacts: phone is "+phone);
contacts.add(contact);
}
}
if (cursor != null) {
cursor.close();
}
return contacts;
}
}
Next, we create our ContactViewModel.java
public class ContactViewModel extends ViewModel {
private ContactRepository repository;
private MutableLiveData<List<UserObject>> contacts;
public ContactViewModel(Context context) {
repository = new ContactRepository(context);
contacts = new MutableLiveData<>();
}
public MutableLiveData<List<UserObject>> getContacts() {
contacts.setValue(repository.fetchContacts());
return contacts;
}
}
Next, we create a factory for our ViewModel ContactViewModelFactory.java
public class ContactViewModelFactory implements ViewModelProvider.Factory {
private Context context;
public ContactViewModelFactory(Context context) {
this.context = context;
}
@NonNull
@Override
public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
if (modelClass.isAssignableFrom(ContactViewModel.class)) {
return (T) new ContactViewModel(context);
}
throw new IllegalArgumentException("Unknown ViewModel class");
}
}
Let's not forget to add permission in our AndroidManifest
<uses-permission android:name="android.permission.READ_CONTACTS" />
And finally, we ask for permission in our MainActivity.java
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(new String[]{Manifest.permission.WRITE_CONTACTS,Manifest.permission.READ_CONTACTS,
Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE}, PERMISSION_REQUEST);
}
and bring our contacts to surface
ContactViewModelFactory factory = new ContactViewModelFactory(this);
viewModel = ViewModelProviders.of(this, factory).get(ContactViewModel.class);
viewModel.getContacts().observe(this, new Observer<List<UserObject>>() {
@Override
public void onChanged(@Nullable List<UserObject> userObjects) {
Log.i(TAG, "ViewModel: userObjects size is "+userObjects.size());
Log.i(TAG, "ViewModel: userObjects size is "+userObjects.get(1).getPhone());
}
});
