RxJava + MVP Sign up Form Validation Take Two

SignUpActivity.java

port android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
import android.widget.EditText;
import club.smartsavers.presenters.SignUpPresenter;
import club.smartsavers.presenters.SignUpPresenterImpl;
import com.jakewharton.rxbinding.widget.RxTextView;
import rx.Observable;

public class SignUpActivity extends Activity implements SignUpView {

  EditText firstName;
  EditText lastName;
  EditText email;
  EditText zipCode;
  EditText password;
  Button submitButton;

  SignUpPresenter presenter;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    //must inflate views before presenter
    presenter = new SignUpPresenterImpl(this);
  }

  @Override
  public void showProgress() {

  }

  @Override
  public void hideProgress() {

  }

  @Override
  public void showFirstNameError(CharSequence error) {
    firstName.setError(error);
  }

  @Override
  public void showLastNameError(CharSequence error) {
    lastName.setError(error);
  }

  @Override
  public void showEmailError(CharSequence error) {
    email.setError(error);
  }

  @Override
  public void showZipCodeError(CharSequence error) {
    zipCode.setError(error);
  }

  @Override
  public void showPasswordError(CharSequence error) {
    password.setError(error);
  }

  @Override
  public void navigateToMainScreen() {

  }

  @Override
  public void updateSubmitButtonViewState(boolean enabled) {
    submitButton.setEnabled(enabled);
  }

  @Override
  public Observable<CharSequence> firstName() {
    return RxTextView.textChanges(firstName);
  }

  @Override
  public Observable<CharSequence> lastName() {
    return RxTextView.textChanges(lastName);
  }

  @Override
  public Observable<CharSequence> email() {
    return RxTextView.textChanges(email);
  }

  @Override
  public Observable<CharSequence> zipCode() {
    return RxTextView.textChanges(zipCode);
  }

  @Override
  public Observable<CharSequence> password() {
    return RxTextView.textChanges(password);
  }
}

SignUpPresenter.java

import android.content.Context;
import club.smartsavers.R;
import club.smartsavers.views.SignUpView;
import rx.Observable;
import rx.functions.Action1;
import rx.functions.Func1;
import rx.functions.Func5;

public class SignUpPresenter implements Presenter<SignUpView> {

  private SignUpView signUpView;
  private final Context context;

  public SignUpPresenter(Context context) {
    this.context = context;
  }

  public Func1<CharSequence, Boolean> isFirstNameValid() {
    return textViewAfterTextChangeEvent -> FIRST_NAME_VALIDITY_CHECK;
  }

  public Action1<Boolean> updateFirstNameViewState() {
    return isValid -> {
      if (!isValid) {
        signUpView.showFirstNameError(context.getString(R.string.first_name_field_validity_error));
      }
    };
  }

  public Func1<CharSequence, Boolean> isLastNameValid() {
    return textViewAfterTextChangeEvent -> LAST_NAME_VALIDITY_CHECK;
  }

  public Action1<Boolean> updateLastNameViewState() {
    return isValid -> {
      if (!isValid) {
        signUpView.showLastNameError(context.getString(R.string.last_name_field_validity_error));
      }
    };
  }

  public Func1<CharSequence, Boolean> isEmailValid() {
    return textViewAfterTextChangeEvent -> EMAIL_VALIDITY_CHECK;
  }

  public Action1<Boolean> updateEmailViewState() {
    return isValid -> {
      if (!isValid) {
        signUpView.showEmailError(context.getString(R.string.email_field_validity_error));
      }
    };
  }

  public Func1<CharSequence, Boolean> isZipCodeValid() {
    return textViewAfterTextChangeEvent -> ZIPCODE_VALIDITY_CHECK;
  }

  public Action1<Boolean> updateZipCodeViewState() {
    return isValid -> {
      if (!isValid) {
        signUpView.showZipCodeError(context.getString(R.string.zipcode_field_validity_error));
      }
    };
  }

  public Func1<CharSequence, Boolean> isPasswordValid() {
    return textViewAfterTextChangeEvent -> PASSWORD_VALIDITY_CHECK;
  }

  public Action1<Boolean> updatePasswordViewState() {
    return isValid -> {
      if (!isValid) {
        signUpView.showPasswordError(context.getString(R.string.password_field_validity_error));
      }
    };
  }

  public Func5<Boolean, Boolean, Boolean, Boolean, Boolean, Boolean> isFormValid() {
    return (isFirsNameValid, isLastNameValid, isEmailValid, isZipCodeValid, isPasswordValid) ->
        isFirsNameValid
            && isLastNameValid
            && isEmailValid
            && isZipCodeValid
            && isPasswordValid;
  }

  @Override
  public void attachView(SignUpView mvpView) {
    signUpView = mvpView;

    Observable<Boolean> firstNameObservable = signUpView.firstName().map(isFirstNameValid());
    Observable<Boolean> lastNameObservable = signUpView.lastName().map(isLastNameValid());
    Observable<Boolean> emailObservable = signUpView.email().map(isEmailValid());
    Observable<Boolean> zipCodeObservable = signUpView.zipCode().map(isZipCodeValid());
    Observable<Boolean> passwordObservable = signUpView.password().map(isPasswordValid());

    firstNameObservable.subscribe(updateFirstNameViewState());
    lastNameObservable.subscribe(updateLastNameViewState());
    emailObservable.subscribe(updateEmailViewState());
    zipCodeObservable.subscribe(updateZipCodeViewState());
    passwordObservable.subscribe(updatePasswordViewState());

    Observable.combineLatest(firstNameObservable, lastNameObservable, emailObservable,
        zipCodeObservable, passwordObservable, isFormValid()).subscribe(isValid -> {
      signUpView.updateSubmitButtonViewState(isValid);
    });
  }

  @Override
  public void detachView() {

  }
}

SignUpView.java

import rx.Observable;

public interface SignUpView extends BaseView {

  void showProgress();

  void hideProgress();

  Observable<CharSequence> firstName();

  Observable<CharSequence> lastName();

  Observable<CharSequence> email();

  Observable<CharSequence> zipCode();

  Observable<CharSequence> password();

  void showFirstNameError(CharSequence error);

  void showLastNameError(CharSequence error);

  void showEmailError(CharSequence error);

  void showZipCodeError(CharSequence error);

  void showPasswordError(CharSequence error);

  void updateSubmitButtonViewState(boolean enabled);

  void navigateToMainScreen();
}

Why don't you return the ResId of string in the presenter and u can leave the context where it belongs to.

I don't think that you can pass Context to presenter , since Context is from android.* and you can't use android.* in presenter you have to decouple the presenter class from android API completely

I don't think that you can pass Context to presenter , since Context is from android.* and you can't use android.* in presenter you have to decouple the presenter class from android API completely

I agree with you, as far as I know context should not pass to the presenter.