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();
}

Not sure you are using multiple subscriptions or not on TextView. But if so then it might cause concurrency issue whenever any subscriber faces error.

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.