When I receive a response from the server, I create a new fragment. If the application is minimized I get an error

io.reactivex.exceptions.OnErrorNotImplementedException: Can not perform this action after onSaveInstanceState

    public void render(LogoViewState logoViewState) {
        if (logoViewState instanceof LogoViewState.LoadingState) {
            statusView.setText("Connecting...");
        } else if (logoViewState instanceof LogoViewState.DataState) {
            statusView.setText(logoViewState.toString());
            if (getActivity() != null) {
                ((MainActivity)getActivity()).showHomeFragment();
            }
        }
    }

Hi! Great library, but I think it is not radical enough and doesn't solve main problem: Activities and Fragments. Fragments are crap and so are Activities. So if you want to make good MVP/MVC/MVVP library for android, you have to discard any Fragment and Activity usage. More on that can be read here, for example: https://corner.squareup.com/2014/10/advocating-against-android-fragments.html

For last week I'm building something very similar in concept to your library — basically the liberal port of iOS's ViewControllers to Android: http://www.youtube.com/watch?v=4S4vr23qB7k It have ViewController, NavigationController and TabController with backstack and up button support.

Example of my library: https://github.com/virl/vcdroid

Today I cloned your repo and now I'm trying to run samples. I don't know why, but gradle can't build them. I'm receiving following errors:

e.g. sample project

/mosby/mvp/src/main/java/com/hannesdorfmann/mosby/mvp/MvpActivity.java Error:(20, 32) error: cannot find symbol class MosbyActivity Error:(29, 67) error: cannot find symbol class MosbyActivity /mosby/mvp/src/main/java/com/hannesdorfmann/mosby/mvp/layout/MvpFrameLayout.java Error:(7, 19) error: package butterknife does not exist /mosby/mvp/src/main/java/com/hannesdorfmann/mosby/mvp/layout/MvpLinearLayout.java Error:(7, 19) error: package butterknife does not exist /mosby/mvp/src/main/java/com/hannesdorfmann/mosby/mvp/layout/MvpRelativeLayout.java Error:(7, 19) error: package butterknife does not exist /mosby/mvp/src/main/java/com/hannesdorfmann/mosby/mvp/lce/LceAnimator.java ...

I'm using Android Studio 1.2 Build 3. Why can't I build them? Can you help me?

After updating the support library of my project to the new AndroidX scheme, the app started crashing after calling this method: BackstackAccessor.isFragmentOnBackStack(Fragment()) Crash: java.lang.IllegalAccessError: Method 'boolean androidx.fragment.app.Fragment.isInBackStack()' is inaccessible to class 'androidx.core.app.BackstackAccessor'

After some investigation, I found that the issue is this file: https://github.com/sockeqwe/mosby/blob/master/utils-fragment/src/main/java/android/support/v4/app/BackstackAccessor.java which is accessing a non-public field by "faking" the package.

As well as being a bad practice, this stops working after migrating to AndroidX due to the change of package names.

Ideally this should be reverted to the commented-out version of the code still existing in the linked file.

I can not reproduce it, As it was one some random users device, I just caught it in Crashlytics. Here is the crashlytics report ( with whole exception and other device/android details ) http://crashes.to/s/de64b446301/details

Does it have anything to do with ParclablePlease ( or it's pro-guard configuration )? Or Any other Mosby components ?

This is the first time such error has occurred and it doesn't see on a new device. it is a kind of old device. App works fine in many devices as I can see in the analytcis and crashlytics.

Some discussion in similar Stack Overflow with similar question
http://stackoverflow.com/questions/13997550/unmarshalling-errors-in-android-app-with-custom-parcelable-classes

Pasting the stack trace here as well

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.timesbuzz.news/com.timesbuzz.news.MainActivity}: java.lang.RuntimeException: Parcel android.os.Parcel@40da0ad0: Unmarshalling unknown type code 47068 at offset 304 at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2205) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2240) at android.app.ActivityThread.access$600(ActivityThread.java:139) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1262) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:156) at android.app.ActivityThread.main(ActivityThread.java:4987) at java.lang.reflect.Method.invokeNative(Method.java) at java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) at dalvik.system.NativeStart.main(NativeStart.java) Caused by: java.lang.RuntimeException: Parcel android.os.Parcel@40da0ad0: Unmarshalling unknown type code 47068 at offset 304 at android.os.Parcel.readValue(Parcel.java:1926) at android.os.Parcel.readMapInternal(Parcel.java:2098) at android.os.Bundle.unparcel(Bundle.java:223) at android.os.Bundle.getParcelable(Bundle.java:1158) at android.app.Activity.onCreate(Activity.java:900) at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:255) at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:122) at com.hannesdorfmann.mosby.MosbyActivity.onCreate(MosbyActivity.java:38) at com.hannesdorfmann.mosby.mvp.MvpActivity.onCreate(MvpActivity.java:34) at com.timesbuzz.news.MainActivity.onCreate(MainActivity.java:58) at android.app.Activity.performCreate(Activity.java:4538) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1071) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2161) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2240) at android.app.ActivityThread.access$600(ActivityThread.java:139) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1262) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:156) at android.app.ActivityThread.main(ActivityThread.java:4987) at java.lang.reflect.Method.invokeNative(Method.java) at java.lang.reflect.Method.invoke(Method.java:511) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) at dalvik.system.NativeStart.main(NativeStart.java)

Seems like an internal bug with eager Observables when establishing the MVI chain.

http://stackoverflow.com/questions/43680876/losing-events-during-rxjava-subscribeon

Hi, I was wondering if you plan to demo unit testing (on the jvm) your presenters. This would be good to test the RXJava Observables. So far I just see instrumentation tests in Mosby samples.

Thanks, Igor

It's almost exactly the same as regular Fragment, I'm not sure if there is an easy way to share the boilerplate code between them.

If anyone does try to add support for DialogFragments, this will keep the dialog on the screen for orientation changes.

    @Override
    public void onDestroyView() {
        if (getDialog() != null && getRetainInstance()) {
            getDialog().setDismissMessage(null);
        }
        ButterKnife.reset(this);
        super.onDestroyView();
    }```

Mosby Version: 3.0.2

Expected behavior Should build with proguard

Actual behavior (include a stacktrace if crash) Not building with proguard:

Warning:com.hannesdorfmann.mosby3.mvp.delegate.FragmentMvpDelegateImpl: can't find referenced class edu.umd.cs.findbugs.annotations.SuppressFBWarnings
Warning:com.hannesdorfmann.mosby3.PresenterManager: can't find referenced class edu.umd.cs.findbugs.annotations.SuppressFBWarnings
Warning:com.hannesdorfmann.mosby3.mvp.delegate.ViewGroupMvpDelegateImpl: can't find referenced class edu.umd.cs.findbugs.annotations.SuppressFBWarnings
Warning:com.hannesdorfmann.mosby3.mvp.delegate.ActivityMvpDelegateImpl: can't find referenced class edu.umd.cs.findbugs.annotations.SuppressFBWarnings
Warning:there were 4 unresolved references to classes or interfaces.

Steps to reproduce the behavior or link to a sample repository Build with enabled proguard

There is how I put fragment in backstack

    private fun <T : Fragment> putContentFragment(fragment: T): T {
        val fragmentTag = fragment.javaClass.name
        logger.debug("putContentFragment: tag: {}", fragmentTag)

        fragmentMng.beginTransaction()
                .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
                .replace(R.id.content_frame_layout, fragment, fragmentTag)
                .addToBackStack(fragmentTag)
                .commit()

        return fragment
    }

And there is how I navigateBack to the previous Fragment:

    override fun navigateBack() {
        if (fragmentMng.backStackEntryCount > 1) {
            callback.forceBackPressed() // it calls super.onBackPressed() for MainActivity
        } else {
            callback.finish() // it calls finish() for MainActivity
        }
    }

I also call setRetainInstance(true) on my Fragment. Class variables are restored as they must. I test it via incrementing int var every onViewCreated():

    private var someValue = 0

    override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        someValue++
        logger.debug("someValue: {}", someValue)
        ...
    }

    override fun createViewState() = NotesViewState()

UPD

Sometimes onNewViewStateInstance() called, sometimes not.

For example, I navigate to new fragment and then return back to the previous: onNewViewStateInstance called only for new NoteFragment and NotesFragment was restored.

Okay. Lets restart my app and do the same:

There it is: onNewViewStateInstance called every time when returning Fragment from backstack

This stacktrace is shown when attempting to detach an Activity that uses MvpNullObjectBasePresenter but does not implement any Interface

java.lang.RuntimeException: Unable to destroy activity {com.mypackage/com.mypackage.ui.account.AccountActivity}: java.lang.IllegalArgumentException: class java.lang.Object is not an interface
at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3831)
at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3849)
        at android.app.ActivityThread.-wrap5(ActivityThread.java)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1398)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:148)
        at android.app.ActivityThread.main(ActivityThread.java:5422)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
        Caused by: java.lang.IllegalArgumentException: class java.lang.Object is not an interface
at java.lang.reflect.Proxy.getProxyClass(Proxy.java:147)
        at java.lang.reflect.Proxy.newProxyInstance(Proxy.java:228)
        at com.hannesdorfmann.mosby.mvp.NoOp.of(NoOp.java:41)
        at com.hannesdorfmann.mosby.mvp.MvpNullObjectBasePresenter.detachView(MvpNullObjectBasePresenter.java:42)
        at com.hannesdorfmann.mosby.mvp.delegate.MvpInternalDelegate.detachView(MvpInternalDelegate.java:70)
        at com.hannesdorfmann.mosby.mvp.delegate.ActivityMvpDelegateImpl.onDestroy(ActivityMvpDelegateImpl.java:71)
        at com.hannesdorfmann.mosby.mvp.MvpActivity.onDestroy(MvpActivity.java:47)
        at android.app.Activity.performDestroy(Activity.java:6422)
        at android.app.Instrumentation.callActivityOnDestroy(Instrumentation.java:1142)
        at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3818)
        at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3849) 
        at android.app.ActivityThread.-wrap5(ActivityThread.java) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1398) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:148) 
        at android.app.ActivityThread.main(ActivityThread.java:5422) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 

I feel that the error message could be improved by checking in MvpNullObjectBasePresenter if the class to be detached implements MvpView, but I'm not sure if that's the best way, I haven't dig too much into Mosby code

Class<V> viewClass = (Class<V>) types[0];
//add check here? Throw an Exception if it doesn't implement MvpView?
view = NoOp.of(viewClass);

Also, this error is only happening in release version with ProGuard. It's been in development like that for months and it hasn't crashed.

Configuration on demand. Configuration on demand tells Gradle to configure modules that only are relevant to the requested tasks instead of configuring all of them. We can enable this feature by setting org.gradle.configureondemand=true.

===================== If there are any inappropriate modifications in this PR, please give me a reply and I will change them.

Mosby Version: 3.1.1

Expected behavior Not to crash.

Actual behavior (include a stacktrace if crash)

Fatal Exception: java.lang.IllegalArgumentException: The generic type <V extends MvpView> must be the first generic type argument of class PostRegisterPresenter (per convention). Otherwise we can't determine which type of View this Presenter coordinates.
       at com.hannesdorfmann.mosby3.mvp.MvpNullObjectBasePresenter.<init>(MvpNullObjectBasePresenter.java:73)
       at mypackage.com.sdk.ui.base.BasePresenter.<init>(BasePresenter.java:15)
       at mypackage.com.sdk.ui.flow.register.PostRegisterPresenter.<init>(PostRegisterPresenter.java:16)
       at mypackage.com.sdk.core.di.module.PresenterModule.providePostRegisterPresenter(PresenterModule.java:227)
       at mypackage.com.sdk.core.di.module.PresenterModule_ProvidePostRegisterPresenterFactory.providePostRegisterPresenter(PresenterModule_ProvidePostRegisterPresenterFactory.java:29)
       at mypackage.com.sdk.core.di.component.DaggerLiveDIComponent.injectPostRegisterFragment(DaggerLiveDIComponent.java:786)
       at mypackage.com.sdk.core.di.component.DaggerLiveDIComponent.inject(DaggerLiveDIComponent.java:516)
       at mypackage.com.sdk.ui.flow.register.PostRegisterFragment.injectFragment(PostRegisterFragment.java:76)
       at mypackage.com.sdk.ui.base.BaseFragment.onAttach(BaseFragment.java:115)
       at androidx.fragment.app.Fragment.onAttach(Fragment.java:1603)
       at androidx.fragment.app.Fragment.performAttach(Fragment.java:2673)
       at androidx.fragment.app.FragmentStateManager.attach(FragmentStateManager.java:263)
       at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1182)
       at androidx.fragment.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1255)
       at androidx.fragment.app.FragmentTransition.calculateFragments(FragmentTransition.java:1138)
       at androidx.fragment.app.FragmentTransition.startTransitions(FragmentTransition.java:136)
       at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2001)
       at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1959)
       at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1861)
       at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413)
       at android.os.Handler.handleCallback(Handler.java:873)
       at android.os.Handler.dispatchMessage(Handler.java:99)
       at android.os.Looper.loop(Looper.java:214)
       at android.app.ActivityThread.main(ActivityThread.java:7094)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)

Caused by java.lang.ClassCastException: libcore.reflect.TypeVariableImpl cannot be cast to java.lang.Class
       at com.hannesdorfmann.mosby3.mvp.MvpNullObjectBasePresenter.<init>(MvpNullObjectBasePresenter.java:58)
       at mypackage.com.ui.base.BasePresenter.<init>(BasePresenter.java:15)
       at mypackage.com.ui.flow.register.PostRegisterPresenter.<init>(PostRegisterPresenter.java:16)
       at mypackage.com.core.di.module.PresenterModule.providePostRegisterPresenter(PresenterModule.java:227)
       at mypackage.com.core.di.module.PresenterModule_ProvidePostRegisterPresenterFactory.providePostRegisterPresenter(PresenterModule_ProvidePostRegisterPresenterFactory.java:29)
       at mypackage.com.core.di.component.DaggerLiveDIComponent.injectPostRegisterFragment(DaggerLiveDIComponent.java:786)
       at mypackage.com.core.di.component.DaggerLiveDIComponent.inject(DaggerLiveDIComponent.java:516)
       at mypackage.com.ui.flow.register.PostRegisterFragment.injectFragment(PostRegisterFragment.java:76)
       at mypackage.com.ui.base.BaseFragment.onAttach(BaseFragment.java:115)
       at androidx.fragment.app.Fragment.onAttach(Fragment.java:1603)
       at androidx.fragment.app.Fragment.performAttach(Fragment.java:2673)
       at androidx.fragment.app.FragmentStateManager.attach(FragmentStateManager.java:263)
       at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1182)
       at androidx.fragment.app.FragmentTransition.addToFirstInLastOut(FragmentTransition.java:1255)
       at androidx.fragment.app.FragmentTransition.calculateFragments(FragmentTransition.java:1138)
       at androidx.fragment.app.FragmentTransition.startTransitions(FragmentTransition.java:136)
       at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2001)
       at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1959)
       at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1861)
       at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413)
       at android.os.Handler.handleCallback(Handler.java:873)
       at android.os.Handler.dispatchMessage(Handler.java:99)
       at android.os.Looper.loop(Looper.java:214)
       at android.app.ActivityThread.main(ActivityThread.java:7094)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:975)

Our classes:

@EFragment
public class PostRegisterFragment extends BaseFragment<PostRegisterView, PostRegisterPresenter> implements PostRegisterView

public abstract class BaseFragment<V extends BaseView, P extends BasePresenter<V>> extends MvpFragment<V, P> implements BaseView

public interface PostRegisterView extends BaseView

public interface BaseView extends MvpView

public class PostRegisterPresenter extends BasePresenter<PostRegisterView>

public abstract class BasePresenter<V extends BaseView> extends MvpNullObjectBasePresenter<V>

Steps to reproduce the behavior or link to a sample repository

• We received the logs from Google Play Store crashlytics. Until now we do not have any replication steps.
• It seems that it doesn't affect all of our users.
• Also we have proguard enabled.
• The issue appeared out of the blue, we did not made any changes at those classes in our latest release.
• We used to have mosby 2.0.1 when we first got the issue yesterday, we updated to 3.1.1 in order to fix the problem.
• The problem seems to be contained a little but it still persists.

Mosby Version: 3.1.1

Expected behavior

MviPresenter$classes instances should be garbage collected after leaving fragment and its activity host and not bound to any INSTANCE object

Actual behavior (include a stacktrace if crash) No crash associated.

The problem is that the generated synthetic classes instances in presenter are somehow bounded to an INSTANCE that is not garbage collected after leaving the screen despite several attempts to force GC on Android profiler.

Most certain the synthetic classes can probably be the anonymous functions in the flatMap calls

See

Snippet of source code of presenter

This presenter lifecycle is being handled by mosby and not reference nor it is being passed to any other component outside the Fragment it belongs to.

The TakePhotoInteractor instance is created on demand also

Steps to reproduce the behavior or link to a sample repository

Just implement this library and follow http://hannesdorfmann.com/android/mosby3-mvi-2

Doesnt mosby disposes that observables created from the view intents?

Any thoughts about this?

App process killed -> conductor setRoot() called (back stack is not empty) -> postDestroy() called on controllers in the backstack -> destroy() called on a null presenter -> crash happened.

Unfortunately Mosby V3 is not compatable with AndroidX as accessing the backstack to see if a fragment is still in use (or presenter can be released) is not possible anymore in androidx as the method to get this information is "blacklisted" and no accessible from the outside anymore (it was in support.v4 days) see #338 #336

Any workaround suggested in #338 seems to me fragile. Therefore I considering the following: What we actually need is a lifecycle callback that tells us when the Fragment is actually destroyed. We could get this information by using AndroidX ViewModel,onCleared().

This will not be breaking change, rather it's a minor implementation detail under the hood.

What do you think?

Need help to solve this error

java.lang.IllegalAccessError: Method 'boolean androidx.fragment.app.Fragment.isInBackStack()' is inaccessible to class 'androidx.core.app.BackstackAccessor'

I read on release to use BackstackAccessor.isFragmentOnBackStack(Fragment()).

where should I use this line of code?