Injection Holder

Injection Holder is a lightweight library that helps DI components (such as Dagger2 components) to stay alive during Activity/Fragment lifecycle.

Also you don't have to worry about storing your DI components and operations with them such as adding/getting/removing etc.

Finally, you can use it in any objects, that can be recreate

Capabilities

Injection Holder has next features:

• Automated adding and clearing of DI component in Activity/Fragment without boilerplate code
• DI Component stay alive after Activity/Fragment recreation
• Available for using in custom views
• Support of AppCompat & AndroidX
• Can be used in Java modules

Getting started

AndroidX

implementation 'com.github.chernovdmitriy.injectionholder:androidx:LATEST_VERSION'

Let's look at the sample

First of all, you will register Activity/Fragment lifecycle callbacks at launch of your application

class MyApplication : Application() {
    override fun onCreate() {
        super.onCreate()
        InjectionHolderX.init(this)
    }
}

Then you just implements ComponentOwner<DiComponentType> interface in your Fragment/Activity

class MyFragment : Fragment(), ComponentOwner<SubComponent> {
    override fun inject(subComponent: SubComponent) = subComponent.inject(this)
 
    override fun provideComponent(): SubComponent {
        return InjectionHolderX
            .findComponent(ParentComponent::class.java)
            .subComponentBuilder()
            .build()
    }
}

Additionally, since 1.1.0 version interface BundleComponentOwner has been added, which give access to Bundle of your savedInstanceState (if Activity/Fragment have been restored) at component providing. In that case your code will looks similarly simple

class MyFragment : Fragment(), BundleComponentOwner<MyComponent> {
    override fun inject(myComponent: MyComponent) = myComponent.inject(this)
 
    override fun provideComponent(savedState: Bundle?): MyComponent {
        val savedStateString: String? = savedState?.getString(ARGUMENT_SAMPLE_KEY)
        return MyComponentProvider.getInstance(savedStateString).myComponent
    }
}

If you use Java and/or Activity/Fragment instances of one class in one time, you should override method getComponentKey() of ComponentOwner

class SomeFeatureBaseFragment : Fragment(), ComponentOwner<SubOfSubComponent> {
    override fun inject(subOfSubComponent: SubOfSubComponent) = subOfSubComponent.inject(this)
 
    override fun provideComponent(): SubOfSubComponent {
        return InjectionHolderX
            .findComponent(SubComponent::class.java)
            .subOfSubComponentBuilder()
            .build()
    }
    
    override fun getComponentKey() = arguments?.getString(SomeFeatureData.EXTRA) ?: javaClass.toString()
}

And that's all what you need!

You're welcome ;)

AppCompat

implementation 'com.github.chernovdmitriy.injectionholder:appcompat:LATEST_VERSION'

Using of AppCompat is identical to AndroidX except InjectionHolder object. You just call InjectionHolderAppCompat instead of InjectionHolderX

Java/Kotlin

implementation 'com.github.chernovdmitriy.injectionholder:core:LATEST_VERSION'

You should provide subclass of InjectionHolder and use it in your application instance. DI components will be stayed alive automatically (This logic must be implements by LifecycleCallbacksRegistry)

License

The MIT License (MIT)

Copyright (c) 2019 Chernov Dmitriy

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.