https://github.com/glung/elm-architecture-android

An example of the ELM architecture on Android using Kotlin with Anko
https://github.com/glung/elm-architecture-android

Last synced: 2 months ago
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An example of the ELM architecture on Android using Kotlin with Anko

• Host: GitHub
• URL: https://github.com/glung/elm-architecture-android
• Owner: glung
• License: mit
• Created: 2015-10-18T13:55:15.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2016-10-05T19:04:50.000Z (over 7 years ago)
• Last Synced: 2024-01-08T21:58:53.421Z (6 months ago)
• Language: Kotlin
• Homepage:
• Size: 69.3 KB
• Stars: 59
• Watchers: 6
• Forks: 4
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Lists

• awesome-elm - Elm Architecture in Android - An example Android application implemented with the Elm Architecture using the Kotlin programming language and Anko library. (Examples / Other editors)
• Awesome-BigData - Elm Architecture in Android - An example Android application implemented with the Elm Architecture using the Kotlin programming language and Anko library. (Examples)

README

        
# elm-architecture-android

An example of the [ELM architecture](https://github.com/evancz/elm-architecture-tutorial/) applied to Android using [Kotlin](kotlinlang.org) with [Anko](https://github.com/JetBrains/anko).

# Activity

The [MainActivity](app/src/main/java/glung/elm_architecture/MainActivity.kt) defines a dispatch method (outside of its scope). 

The `dispatch` method : 

- `update` the model

- `render` a view for the updated model

- `setContentView` with the view representing the updated model.

`onCreate` the activity initialize the system with an `INIT` action and a new `Model`.  

```

public class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {

        super.onCreate(savedInstanceState)

        dispatch(this)

    }

}

fun dispatch(activity: Activity, action: Action = Action.INIT, model: Model = Model()) {

    val updatedModel = update(action, model)

    val dispatch = dispatch(activity, updatedModel)

    activity.setContentView(view(activity, updatedModel, dispatch))

}

fun dispatch(activity: Activity, model: Model) = { newAction: Action ->

    dispatch(activity, newAction, model)

}

```

# The Counter

All the application logic is in [Counter.kt](app/src/main/java/glung/elm_architecture/counter.kt). 

The file 

- declares the `Model`

- declares the `Action`

- implements the `update` function 

- implements the `view` function 

```

sealed class Action {

    object INIT : Action()

    object UP : Action()

    object DOWN : Action()

}

data class Model(val counter: Int = 0)

fun update(action: Action, model: Model): Model {

    return when (action) {

        is Action.INIT -> Model()

        is Action.UP -> Model(model.counter + 1)

        is Action.DOWN -> Model(model.counter - 1)

    }

}

fun view(context: Context, model: Model, dispatch : (Action) -> Unit): LinearLayout {

    with(context) {

        return verticalLayout {

            button("up") {

                onClick { dispatch(Action.UP) }

            }

            button("down") {

                onClick { dispatch(Action.DOWN) }

            }

            textView(model.counter.toString())

        }

    }

}

```

# Note 

This is experimental and made for a talk. Feedback welcomed.

[@lungos](https://twitter.com/Lungos)