Add mutableCollectionState and docs.

build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
 }
 
 group = "nl.astraeus"
-version = "1.0.0"
+version = "1.0.1-SNAPSHOT"
 
 repositories {
   mavenCentral()

docs/getting-started.md

@@ -0,0 +1,136 @@
+# Table of contents
+
+[home](home.md)
+[getting started](getting-started.md)
+
+# Getting started
+
+To get started create a new kotlin project in intellij of the type 'Browser application'
+
+![Create 'Browser Application' project](/docs/img/create-project.png "Create 'Browser Application' project")
+
+Add the 'sourceSets' block with the kotlin-komponent dependency so your build.gradle.kts looks like this:
+
+```gradle
+plugins {
+    kotlin("js") version "1.6.10"
+}
+
+group = "com.test"
+version = "1.0.0-SNAPSHOT"
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    api("nl.astraeus:kotlin-komponent-js:1.0.0")
+
+    testImplementation(kotlin("test"))
+}
+
+kotlin {
+    js(IR) {
+        binaries.executable()
+        browser {
+            commonWebpackConfig {
+                cssSupport.enabled = true
+            }
+        }
+    }
+}
+```
+
+Refresh the gradle project to import the dependency.
+
+There is now only one kt file in the project called Simple.kt, it should look like this:
+
+```kotin
+fun main() {
+  console.log("Hello, ${greet()}")
+}
+
+fun greet() = "world"
+```
+
+Replace the code in the file with the following for a simple click app:
+
+```koltin
+import kotlinx.browser.document
+import kotlinx.html.button
+import kotlinx.html.div
+import kotlinx.html.hr
+import kotlinx.html.js.onClickFunction
+import nl.astraeus.komp.HtmlBuilder
+import nl.astraeus.komp.Komponent
+import nl.astraeus.komp.mutableCollectionState
+import nl.astraeus.komp.state
+import kotlin.js.Date
+
+fun main() {
+  console.log("Hello, ${greet()}")
+
+  Komponent.create(document.body!!, TestKomponent())
+}
+
+fun greet() = "world"
+
+class TestKomponent : Komponent() {
+  var clicks: Int = 0
+  val lines: MutableCollection<String> = mutableListOf()
+
+  override fun HtmlBuilder.render() {
+    div {
+      div {
+        +"Hello Komponent!"
+      }
+
+      div {
+        +"Clicks $clicks"
+      }
+
+      div {
+        button {
+          +"Click"
+          onClickFunction = {
+            clicks++
+            lines.add("click $clicks at ${Date()}")
+            requestUpdate()
+          }
+        }
+      }
+
+      hr()
+
+      for (line in lines) {
+        div {
+          + line
+        }
+      }
+
+    }
+  }
+}
+```
+
+First in the main we add our TestKomponent to the document body with the following line:
+
+```kotlin
+  Komponent.create(document.body!!, TestKomponent())
+```
+
+The TestKomponent.render method will be called to render our Komponent. 
+As you can see events can be attached inline with the on<event>Function methods.
+The requestUpdate method will call the render method again and update the page accordingly.
+
+If you like you can use some helpers that will automatically call the requestUpdate method if
+the data changes, that would look like this:
+
+```kotlin
+  var clicks: Int by state(0)
+  val lines: MutableCollection<String> = mutableCollectionState(mutableListOf())
+```
+
+In that case you can remove the requestUpdate call from the onClickFunction.
+
+You can find a working repository of this example here: [example]()

docs/home.md

@@ -0,0 +1,4 @@
+# Table of contents
+
+[home](home.md)
+[getting started](getting-started.md)

src/jsMain/kotlin/nl/astraeus/komp/MutableCollectionStateDelegate.kt

@@ -0,0 +1,54 @@
+package nl.astraeus.komp
+
+inline fun <reified T> Komponent.mutableCollectionState(
+  initialValue: MutableCollection<T>
+): MutableCollection<T> = MutableCollectionStateDelegate(
+  this,
+  initialValue
+)
+
+class MutableCollectionStateDelegate<T>(
+  val komponent: Komponent,
+  val collection: MutableCollection<T>
+): MutableCollection<T> by collection {
+
+  override fun add(element: T): Boolean {
+    komponent.requestUpdate()
+
+    return collection.add(element)
+  }
+
+  override fun addAll(elements: Collection<T>): Boolean {
+    komponent.requestUpdate()
+
+    return collection.addAll(elements)
+  }
+
+  override fun clear() {
+    komponent.requestUpdate()
+
+    collection.clear()
+  }
+
+  // todo: return iterator wrapper to update at changes?
+  // override fun iterator(): MutableIterator<T> = collection.iterator()
+
+  override fun remove(element: T): Boolean {
+    komponent.requestUpdate()
+
+    return collection.remove(element)
+  }
+
+  override fun removeAll(elements: Collection<T>): Boolean {
+    komponent.requestUpdate()
+
+    return collection.removeAll(elements)
+  }
+
+  override fun retainAll(elements: Collection<T>): Boolean {
+    komponent.requestUpdate()
+
+    return collection.retainAll(elements)
+  }
+
+}

src/jsMain/kotlin/nl/astraeus/komp/State.kt

@@ -2,20 +2,41 @@ package nl.astraeus.komp
 
 import kotlin.reflect.KProperty
 
-class StateDelegate<T>(
-  val komponent: Komponent,
-  initialValue: T
-) {
-  var value: T = initialValue
+interface Delegate<T> {
 
   operator fun getValue(
     thisRef: Any?,
     property: KProperty<*>
+  ): T
+
+  operator fun setValue(
+    thisRef: Any?,
+    property: KProperty<*>,
+    value: T
+  )
+}
+
+
+open class StateDelegate<T>(
+  val komponent: Komponent,
+  initialValue: T
+) : Delegate<T> {
+  private var value: T = initialValue
+
+  init {
+    if (value is MutableCollection<*>) {
+      error("Use mutableList to create a collection!")
+    }
+  }
+
+  override operator fun getValue(
+    thisRef: Any?,
+    property: KProperty<*>
   ): T {
     return value
   }
 
-  operator fun setValue(
+  override operator fun setValue(
     thisRef: Any?,
     property: KProperty<*>,
     value: T
@@ -29,7 +50,7 @@ class StateDelegate<T>(
 
 inline fun <reified T> Komponent.state(
   initialValue: T
-): StateDelegate<T> = StateDelegate(
-  this,
-  initialValue
-)
+): Delegate<T> = StateDelegate(
+      this,
+      initialValue
+    )