CODEWITHSUNDEEP
javaandroidrealm
Spidey
Spidey

Reputation: 397

Adding methods in Realm objects through interface

I am trying to make a listview with headers as follow by using queries to retrieve the favourite school and its favourite students using Realm.

Point Grey Secondary
Kent
Jane

My question is whether I could implement methods in realm objects so I can use the method to find out if the realm result is header or items, if it couldn't be done, how I can get around and still print the header and the listview from realm result.

I also have an error when it compile the following code. It says "getters isHeader is not associated with any field"

My interface Class:

public interface Item {

 boolean isHeader();

}

My models class:

public class School extends RealmObject implements Item{

@Required
private String SchoolID;
private String SchoolName;
private RealmList<Student> Students;


@Ignore
private boolean answerSchool = true;

public boolean isHeader() {
    return answerSchool;
}

getters/ setters
}

public class Student extends RealmObject implements Item {

@Required
private String StudentID;
private String StudentName;
private Boolean StudentFavourite;


@Ignore
private boolean answerStudent = false;

public boolean isHeader() {
    return  answerStudent;
}
getters /setters

}

My Adapter Class

public class FavourAdapter extends ArrayAdapter<Item> {

private Context context;
private ArrayList<Item> items;
private LayoutInflater vi;



public FavourAdapter(Context context, ArrayList<Item> Items) {
    super(context, 0, Items);
    this.context = context;
    vi = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View v = convertView;

    final Item i = items.get(position);
    if (i != null) {
        if(i.isHeader()){

    // Is si School ok in realm?
    School si = (School)i;
            v = vi.inflate(R.layout.row_favour_school, parent, false);


            final TextView headerSection = (TextView) v.findViewById(R.id.rowFavSchoolName);
            headerSection.setText(si.getSchoolName());

        }else{
            // Can I declare studentRow as Student in realm?
            Student studentRow = (Student)i;
            v = vi.inflate(R.layout.row_favour_student, parent, false);
            final TextView title = (TextView)v.findViewById(R.id.rowFavStudentName);



            if (title != null)
                title.setText(studentRow.getStudentName());

        }
    }
    return v;
}

}

My main activity class:

public class FavourActivity extends AppCompatActivity  {

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

    Realm realm = Realm.getDefaultInstance();
    ArrayList<Item> items = new ArrayList<Item>();
    ListView listview=null;
    listview=(ListView)findViewById(R.id.favStudents_list);

    //Retrieve all the school object if they have any favourite students.
    RealmResults<School> schools = realm.where(School.class).equalTo("Students.StudentFavourite", true).findAll();
    //Get the first favourite school
    items.add(schools.get(0));

    //Retrieve all the favourite student from the first favourite school.
    RealmResults<Student> favStudents = schools.get(0).getStudents().where().equalTo("StudentFavourite", true).findAll();

    items.add(favStudents.get(0));
    items.add(favStudents.get(1));

    FavourAdapter fAdapter = new FavourAdapter(this, items);
    listview.setAdapter(fAdapter);


    //Log.d("fav", String.valueOf(favStudents));



 }

Upvotes: 1

Views: 402

Answers (1)

Adam S
Adam S

Reputation: 16394

Currently (Realm 0.87.x and below) a Realm object can only have default getters and setters - no other methods are allowed.

isHeader is default Java style for the getter for a boolean member, so Realm is expecting a private boolean header; declaration, which obviously doesn't exist.

A comment on this answer from one of the Realm developers indicates that this restriction may be lifted in Realm 0.88 - in fact, the pull request in question has been merged, so this feature will probably be available soon!

Upvotes: 2

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