Android app for Droidcon Madrid 2019

DI

The project uses dagger/dagger-android as DI framework. In the next sections you'll see some guides to work with our dagger set up.

Activity

To create a new activity and make DI work on it you have to only add a new binding on ActivityBindingModule for the correspondent activity indicating the modules it needs in order to work

@ActivityScope
@ContributesAndroidInjector(
    modules = [
        InfoModule::class
    ]
)
abstract fun homeActivity(): HomeActivity

Also, your activity must extend `DaggerAppCompatActivity

Fragment

To create a new fragment and make DI work on it you have to follow the next steps:

• Add the next method to the dagger module of the feature using the current sample fragment:

@FragmentScope
@ContributesAndroidInjector
abstract fun contributeInfoFragment(): InfoFragment

• Add the mentioned dagger module to the module array the activity containing the fragment has in its binding (e.g. InfoModule is the dagger module correspondent to the fragment)

@ActivityScope
@ContributesAndroidInjector(
    modules = [
        InfoModule::class
    ]
)
abstract fun homeActivity(): HomeActivity

• Also, your fragment must extend `DaggerFragment

View Model

To build a view model you have to create the view model class by extending ViewModel and adding all its dependencies in the constructor without annotating it with @Inject annotation.

Then you have to create a ViewModelFactory for your view model. This factory will have all the dependencies of the ViewModel on its constructor, that will be annotated with @Inject. Finally, we have to create a method get in the factory that receives a Fragment or FragmentActivity as parameter. Inside that method you can use the extension function Fragment.buildViewModel to build the view model.

class InfoFragmentViewModelFactory @Inject constructor() {

    fun get(fragment: Fragment): InfoFragmentViewModel = fragment.buildViewModel {
        InfoFragmentViewModel()
    }
}

Then use the view model and the factory in the next way:

class InfoFragment private constructor() : DaggerFragment() {

    @Inject
    lateinit var infoFragmentViewModelFactory: InfoFragmentViewModelFactory
    private lateinit var infoFragmentViewModel: InfoFragmentViewModel

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View = inflater.inflate(R.layout.fragment_info, container, false)

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        infoFragmentViewModel = infoFragmentViewModelFactory.get(this)
    }

    companion object {
        fun build(): InfoFragment = InfoFragment()
        const val TAG = "fragment:InfoFragment"
    }
}

Run app as instant experience

In Android Studio, go to Run/Edit Configurations... menu.

For each build configuration (app, Instant app, etc), in Installation Settings section, check the Deploy as instant app box. And in the dropdown "Deploy" select Apk from app bundle

Then run the app with the correspondent build configuration. And that's all!

To get back to run/install the app in the standard way open again Run/Edit Configurations... menu. Uncheck Deploy as instant app. Select Default apk from the "Deploy" dropdown. Make a clean build through Build/Rebuild project.

If when running/installing your app in the regular way (non instant app way) you see the following error:

Installation did not succeed.
The application could not be installed.
Installation failed due to: '-27'
Retry

Just execute adb uninstall dev.androidcookers.droidcon and retry