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Eduardo Medina

​

@eduardomedina | emedinaa@gmail.com | github/emedinaa

Android SME Belatrix / Globant

Mapsalud�Instructor en Academia Móviles

Android Dev Perú

Kotlin User Group Perú

IOS Dev Perú�GDG Lima

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MVVM Pattern

Model View ViewModel

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​

MVC Model View Controller

​

MVP Model View Presenter

​

Clean Architecture

​

MVVM Model View ViewModel

Architecture Patterns & Architectures

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https://github.com/emedinaa/kotlin-mvvm

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  • mvvm + tests �https://github.com/emedinaa/kotlin-mvvm/tree/master
  • mvvm + koin + tests

https://github.com/emedinaa/kotlin-mvvm/tree/koin

  • mvvm + coroutines + sealed class + tests

https://github.com/emedinaa/kotlin-mvvm/tree/coroutines

  • mvvm + view binding�https://github.com/emedinaa/kotlin-mvvm/tree/viewbinding
  • mvvm + coroutines + room �https://github.com/emedinaa/kotlin-mvvm/tree/room

Kotlin mvvm samples

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  • mvvm + flow + tests �https://github.com/emedinaa/kotlin-mvvm/tree/flow
  • mvvm + hilt + tests

https://github.com/emedinaa/kotlin-mvvm/tree/hilt

  • mvvm + clean

https://github.com/emedinaa/kotlin-mvvm/tree/clean

  • mvvm + rx (in progress)
  • mvvm + navigation component (in progress)

Kotlin mvvm samples

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https://github.com/emedinaa/kotlin-mvvm

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UI

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Retrofit

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VIEW - DATA

channel

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DataSource

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DataSource

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View - DataSource

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UI

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View - Repository - DataSource

Callback

Callback

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Repository

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UI

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View - ?? - Repository - DataSource

Callback

Callback

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MVVM - Model View ViewModel

Callbacks

Property changed events

UI events

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MVVM - Model View ViewModel

Callbacks

Property changed events

UI events

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View

Observers

UI events

LiveData

Property changed events

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LiveData & Lifecycle

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LiveData & Lifecycle

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UI

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ViewModel

ViewModel provides data for UI components and survive configuration changes.

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View actions

ViewModel

showLoading()

isViewLoading�<Boolean>

hideLoading()

isViewLoading

<Boolean>

errorMessage()

onErrorMessage�<Any>

emptyData()

isEmptyList

<Boolean>

renderMuseums()

museums List<Museum>>

​

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View - ViewModel - Model (Repository | DataSource)

Callback

Callback

Callbacks

Callbacks

LiveData

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ViewModel

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ViewModel

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UI

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Architecture

https://developer.android.com/jetpack/docs/guide

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Unit Tests

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  • Local tests
  • Instrumentation tests

Unit tests

JUnit + Mockito

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Test

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Test

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Test

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Test

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Test

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Test

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Layer

communication

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MVVM - Model View ViewModel

Callbacks

Property changed events

UI events

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Sealed

classes

Operation Result

Success

Error

https://kotlinlang.org/docs/reference/sealed-classes.html

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Sealed classes

OperationResult

Success

Error

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Coroutines

https://kotlinlang.org/docs/reference/coroutines-overview.html

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Coroutines

​

fun fetchCoupons() {

​

viewModelScope.launch {

val result = withContext(Dispatchers.IO) {

repository.retrieveCoupons()

}

}

​

...

}

​

​

fetchCoupons()

onDraw()

onDraw()

renderCoupons()

onDraw()

Other

thread

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DataSource

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ViewModel

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UI

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Unit Tests

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Test

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Test

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Test

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Test

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Test

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Test

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Checklist

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  • Delegate responsibilities to other components. (BL, Data layer, View layer)
  • Consider the lifecycle of android components.
  • Convert your views to Passive Views.
  • Define a rule of dependencies.
  • Refactor and support changes.
  • Easy to create Unit tests.

You should use some architecture pattern...

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MVVM - Model View ViewModel

Property changed events

UI events

Sealed class

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Model

LiveData

request data

Sealed class

Repository

Data source

Entity

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Use Case

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ViewModel

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Property changed events

UI events

Request data

Sealed class

Observers

LiveData

MVVM

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LiveData

MVVM - Clean

Sealed class

Sealed class

DTO

Entity

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Clean Architecture

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DI

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DI

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https://github.com/emedinaa/kotlin-mvvm

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Eduardo Medina

Thank you

@eduardomedina | emedinaa@gmail.com | github/emedinaa

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Android

Dev�Perú

https://www.meetup.com/es-ES/Android-Dev-Peru/