mdfirebase

Tool for accessing firebase realtime database

How to use it

1. Add the JitPack repository to your build file

allprojects {
		repositories {
			...
			maven { url 'https://jitpack.io' }
		}
	}

2. Add the dependency:

dependencies {
		implementation 'com.github.dudziks:mdfirebase:v0.0.9'
}

3. Create Model and Entity classes

data class MyDTO(var text: String)

data class MyModel(var name: String)

4. Implement intereface IMapper

interface IMapper<DTO, Model>  {
    fun mapFromDTO(from: DTO?): Model?
    fun mapToDTO(from: Model?): DTO?
}

// MyDTO - Entity
// MyModel - Model

class MyMapper:  FirebaseMapper<MyDTO, MyModel>() {
	override fun mapFromDTO(from: MyDTO?): MyModel? =
    		from?.run { MyModel(contents = text, theKey = key) }

   	override fun mapToDTO(from: MyModel?): MyDTO? =
		from?.run { MyDTO(text = contents, key = theKey) }
}

6 Use instance of interface IFirebaseDAO<MyDTO, MyModel> for accessing the data.

Example of class using instance of IFirebaseDAO<MyDTO, MyModel>

class MyRepo {

	private val dao: IFirebaseDAO<MyDTO, MyModel> =  FirebaseDAO.Builder<MyDTO, MyModel>()
		.fbUser(Firebase.auth.currentUser)
		.rootNodePath { "path/to/my/data" }
		.mapper(MyMapper())
		.build()


	@ExperimentalCoroutinesApi
	fun getData(): Flow<MmyModel?> =callbackFlow {
		dao.addListener(DefaultFirebaseDBCallback(
		    onAddedCallback = { offer(it) }
		    //onChangedCallback = { /* manage changed data */}
		    //onAddedListCallback = { /* manage changed data */}
		    //onRemovedCallback = { /* manage removed data */}
		    //onDataChangedCallback = { /* manage changed data */}
		    //onErrorCallback = { /* manage error */}		  

		))
		awaitClose { dao.removeListener()
	}	
}

You can override all the callbacks commented out. There are empty default implementation of each callback, so if you wont implement it, it will do nothing.

7. Use the class MyRepo in your Viewmodel

class MyViewModel: ViewModel() {
	val myRepo = MyRepo()

	val liveData = liveData(Dispatchers.IO) {
		myRepo.getData().collect { value -> emit(value) }
	    }
}