KBinding

Android MVVM framework write in kotlin, base on anko, simple but powerful.

Contents

BindingMode

  • OneWay: Binding from model to view
  • TwoWay: Binding from model to view and view to model
  • OneWayToSource: Binding from view to model
  • OneTime: Binding from model to view, and auto release after first emit

Simple Binding

verticalLayout {
    editText {
        bind { text("name", mode = TwoWay) }
    }
    button {
        bind { click("hello") }
    }
}
class SimpleViewModel() : ViewModel() {
    @delegate:Property
    var name: String by Delegates.property("Jason")
    
    // all the parameter for Command is optional, first parameter pass by event Observable, second parameter is lambda (Boolean) -> Unit
    @Command
    val hello(canExecute: (Boolean) -> Unit) {
        toast("Hello, ${name}!")
    }
}

Multiple Binding

//login button enabled only when name and password not empty
class ArrayToBooleanConverter : MultipleConverter<Boolean> {
    override fun convert(params: Array<Any>): Boolean {
        params.forEach {
            if(it.toString().isEmpty()) return false
        }
        return true
    }
}
verticalLayout {
    editText {
        bind { text("name", mode = TwoWay) }
    }
    editText {
            bind { text("password", mode = TwoWay) }
        }
    button {
        bind { enabled("name", "password", mode = OneWay, converter = ArrayToBooleanConverter()) }
        bind { click("login") }
    }
}
class LoginViewModel() : ViewModel() {
    @delegate:Property
    var name: String by Delegates.property("xxx@xxxx.co")
    
    @delegate:Property
    var password: String by Delegates.property("xxxxxx")
    
    @Command
    val login() {
        //login processing
    }
}

DependencyProperty and ExtractProperty

// @DependencyProperty will generate binding for nameAndSymbol depends on stock, stock changes then nameAndSymbol changes
// @ExtractProperty will generate binding for stock properties, for example code below, Property name and price will generated. If hasPrefix = true, then Property stock.name stock.price will generated.
class StockViewModel() : ViewModel() {
    @delegate:ExtractProperty(
        "name", "price",
        hasPrefix = false
    )
    var stock: Stock? by Delegates.property()
    
    @delegate:DependencyProperty("stock")
    var nameAndSymbol: String by Delegates.property { stock?.name + stock?.symbol }
}

Wait/Until

//wait/until just like OneTime binding, but it need apply action, for example below, it wait for market from model, then decide how to display
relativeLayout {
    wait { until("market", converter = viewOfMarket) { inflate(it, this@verticalLayout) }  }
}

Extend Binding Property(Depend on RxBinding heavily)

Event

    fun View.click(path: String) : PropertyBinding = commandBinding(path, clicks(), enabled())

Property

    fun View.enabled(vararg paths: String, mode: OneWay = BindingMode.OneWay, converter: OneWayConverter<Boolean> = EmptyOneWayConverter()) : PropertyBinding = oneWayPropertyBinding(paths, enabled(), false, converter) 
    
    //this implements four binding mode for TextView, if just need OneWay mode, remove last three lines, some for other mode
    fun TextView.text(vararg paths: String, mode: OneWay = BindingMode.OneWay, converter: OneWayConverter<out CharSequence> = EmptyOneWayConverter()) : PropertyBinding = oneWayPropertyBinding(paths, text(), false, converter)
    fun TextView.text(vararg paths: String, mode: OneTime, converter: OneWayConverter<out CharSequence> = EmptyOneWayConverter()) : PropertyBinding = oneWayPropertyBinding(paths, text(), true, converter)
    fun TextView.text(path: String, mode: OneWayToSource, converter: OneWayConverter<*> = EmptyOneWayConverter<String>()) : PropertyBinding = oneWayPropertyBinding(path, textChanges2(), converter)
    fun TextView.text(path: String, mode: TwoWay, converter: TwoWayConverter<String, *> = EmptyTwoWayConverter<String, String>()) : PropertyBinding = twoWayPropertyBinding(path, textChanges2(), text(), converter) 

Using with Gradle

// library with Annotation process dose not upload to bintray yet, coming soon!
dependencies {
    compile 'com.benny.library:kbinding:0.2.0'
    kapt 'com.benny.library:kbinding-compiler:0.2.0'
    
    // for common bindings, View, TextView, and ...
    compile 'com.benny.library:kbinding-common:0.2.0'
    // for recyclerview bindings
    compile 'com.benny.library:kbinding-recyclerview-v7:0.2.0'
    // for support v4 bindings
    compile 'com.benny.library:kbinding-support-v4:0.2.0'
}

Contribute

Now is just the beginning of KBinding, so everyone interested in this library, just fork it and pull requests to me. Let’s make it a little better.

Discussion

QQ Group: 516157585

compile "com.benny.library:kbinding:0.2.4"

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