Property values delegated to a map (idea by tieskedh)

Closes #2

27 files changed, 202 insertions, 805 deletions

diff --git a/src/main/kotlin/pl/treksoft/kvision/core/StyledComponent.kt b/src/main/kotlin/pl/treksoft/kvision/core/StyledComponent.kt
index f0ceb587..d130ec0b 100644
--- a/src/main/kotlin/pl/treksoft/kvision/core/StyledComponent.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/core/StyledComponent.kt
@@ -22,187 +22,102 @@
 package pl.treksoft.kvision.core
 
 import pl.treksoft.kvision.utils.asString
+import kotlin.reflect.KProperty
 
 /**
  * Base class for components supporting CSS styling.
  */
 abstract class StyledComponent : Component {
+    private val propertyValues: MutableMap<String, Any?> = mutableMapOf()
+
     /**
      * Width of the current component.
      */
-    open var width: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    open var width: CssSize? by refreshOnUpdate()
     /**
      * Minimal width of the current component.
      */
-    var minWidth: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var minWidth: CssSize? by refreshOnUpdate()
     /**
      * Maximal width of the current component.
      */
-    var maxWidth: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var maxWidth: CssSize? by refreshOnUpdate()
     /**
      * Height of the current component.
      */
-    var height: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var height: CssSize? by refreshOnUpdate()
     /**
      * Minimal height of the current component.
      */
-    var minHeight: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var minHeight: CssSize? by refreshOnUpdate()
     /**
      * Maximal height of the current component.
      */
-    var maxHeight: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var maxHeight: CssSize? by refreshOnUpdate()
     /**
      * Border of the current component.
      */
-    var border: Border? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var border: Border? by refreshOnUpdate()
     /**
      * Top border of the current component.
      */
-    var borderTop: Border? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var borderTop: Border? by refreshOnUpdate()
     /**
      * Right border of the current component.
      */
-    var borderRight: Border? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var borderRight: Border? by refreshOnUpdate()
     /**
      * Bottom border of the current component.
      */
-    var borderBottom: Border? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var borderBottom: Border? by refreshOnUpdate()
     /**
      * Left border of the current component.
      */
-    var borderLeft: Border? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var borderLeft: Border? by refreshOnUpdate()
     /**
      * Margin of the current component.
      */
-    var margin: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var margin: CssSize? by refreshOnUpdate()
     /**
      * Top margin of the current component.
      */
-    var marginTop: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var marginTop: CssSize? by refreshOnUpdate()
     /**
      * Right margin of the current component.
      */
-    var marginRight: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var marginRight: CssSize? by refreshOnUpdate()
     /**
      * Bottom margin of the current component.
      */
-    var marginBottom: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var marginBottom: CssSize? by refreshOnUpdate()
     /**
      * Left margin of the current component.
      */
-    var marginLeft: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var marginLeft: CssSize? by refreshOnUpdate()
     /**
      * Padding of the current component.
      */
-    var padding: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var padding: CssSize? by refreshOnUpdate()
     /**
      * Top padding of the current component.
      */
-    var paddingTop: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var paddingTop: CssSize? by refreshOnUpdate()
     /**
      * Right padding of the current component.
      */
-    var paddingRight: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var paddingRight: CssSize? by refreshOnUpdate()
     /**
      * Bottom padding of the current component.
      */
-    var paddingBottom: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var paddingBottom: CssSize? by refreshOnUpdate()
     /**
      * Left padding of the current component.
      */
-    var paddingLeft: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var paddingLeft: CssSize? by refreshOnUpdate()
     /**
      * Text color for the current component.
      */
-    var color: Color? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var color: Color? by refreshOnUpdate()
     /**
      * Text color for the current component given in hex format (write only).
      *
@@ -234,19 +149,11 @@ abstract class StyledComponent : Component {
     /**
      * Opacity of the current component.
      */
-    var opacity: Double? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var opacity: Double? by refreshOnUpdate()
     /**
      * Background of the current component.
      */
-    var background: Background? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var background: Background? by refreshOnUpdate()
 
 
     private var snStyleCache: List<StringPair>? = null
@@ -351,4 +258,36 @@ abstract class StyledComponent : Component {
         }
         return snstyle
     }
+
+    internal fun <T> refreshOnUpdate(refreshFunction: ((T) -> Unit) = { this.refresh() }) =
+        RefreshDelegateProvider<T>(null, refreshFunction)
+
+    internal fun <T> refreshOnUpdate(initialValue: T, refreshFunction: ((T) -> Unit) = { this.refresh() }) =
+        RefreshDelegateProvider(initialValue, refreshFunction)
+
+    internal inner class RefreshDelegateProvider<T>(
+        private val initialValue: T?, private val refreshFunction: (T) -> Unit
+    ) {
+        operator fun provideDelegate(thisRef: Any?, prop: KProperty<*>): RefreshDelegate<T> {
+            if (initialValue != null) propertyValues[prop.name] = initialValue
+            return RefreshDelegate(refreshFunction)
+        }
+    }
+
+    internal inner class RefreshDelegate<T>(private val refreshFunction: ((T) -> Unit)) {
+        @Suppress("UNCHECKED_CAST")
+        operator fun getValue(thisRef: StyledComponent, property: KProperty<*>): T {
+            val value = propertyValues[property.name]
+            return if (value != null) {
+                value as T
+            } else {
+                null as T
+            }
+        }
+
+        operator fun setValue(thisRef: StyledComponent, property: KProperty<*>, value: T) {
+            propertyValues[property.name] = value
+            refreshFunction(value)
+        }
+    }
 }
diff --git a/src/main/kotlin/pl/treksoft/kvision/core/Widget.kt b/src/main/kotlin/pl/treksoft/kvision/core/Widget.kt
index f50b1679..a746ffa4 100644
--- a/src/main/kotlin/pl/treksoft/kvision/core/Widget.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/core/Widget.kt
@@ -65,32 +65,18 @@ open class Widget(classes: Set<String> = setOf()) : StyledComponent() {
     /**
      * A title attribute of generated HTML element.
      */
-    var title: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var title: String? by refreshOnUpdate()
     /**
      * An ID attribute of generated HTML element.
      */
-    var id: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var id: String? by refreshOnUpdate()
     /**
      * A role attribute of generated HTML element.
      */
-    var role: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
-    internal var surroundingSpan: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var role: String? by refreshOnUpdate()
+
+    internal var surroundingSpan by refreshOnUpdate(false)
+
     internal var eventTarget: Widget? = null
 
     private var vnode: VNode? = null
diff --git a/src/main/kotlin/pl/treksoft/kvision/dropdown/DropDown.kt b/src/main/kotlin/pl/treksoft/kvision/dropdown/DropDown.kt
index 0f653d30..1370f25a 100644
--- a/src/main/kotlin/pl/treksoft/kvision/dropdown/DropDown.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/dropdown/DropDown.kt
@@ -70,11 +70,7 @@ open class DropDown(
         set(value) {
             button.text = value
         }
-    private var elements = elements
-        set(value) {
-            field = value
-            setChildrenFromElements()
-        }
+    private var elements by refreshOnUpdate(elements, { setChildrenFromElements() })
     /**
      * The icon of the dropdown button.
      */
@@ -126,11 +122,7 @@ open class DropDown(
     /**
      * Determines if the dropdown is showing upwards.
      */
-    var dropup = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var dropup by refreshOnUpdate(false)
     /**
      * Width of the dropdown button.
      */
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/check/CheckBox.kt b/src/main/kotlin/pl/treksoft/kvision/form/check/CheckBox.kt
index 7a8b5905..e76a1c7a 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/check/CheckBox.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/check/CheckBox.kt
@@ -107,27 +107,15 @@ open class CheckBox(
     /**
      * The style (one of Bootstrap standard colors) of the input.
      */
-    var style: CHECKBOXSTYLE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var style: CHECKBOXSTYLE? by refreshOnUpdate()
     /**
      * Determines if the checkbox is rendered as a circle.
      */
-    var circled: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var circled by refreshOnUpdate(false)
     /**
      * Determines if the checkbox is rendered inline.
      */
-    var inline: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var inline by refreshOnUpdate(false)
     /**
      * The size of the input.
      */
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/check/CheckInput.kt b/src/main/kotlin/pl/treksoft/kvision/form/check/CheckInput.kt
index 46e5395c..7c67c957 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/check/CheckInput.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/check/CheckInput.kt
@@ -66,63 +66,34 @@ open class CheckInput(
     /**
      * The selection state of the input.
      */
-    var value: Boolean = value
-        set(value) {
-            field = value
-            refreshState()
-        }
+    var value by refreshOnUpdate(value, { refreshState() })
     /**
      * The value attribute of the generated HTML input element.
      *
      * This value is placed directly in generated HTML code, while the [value] property is dynamically
      * bound to the input selection state.
      */
-    var startValue: Boolean = value
-        set(value) {
-            field = value
-            this.value = value
-            refresh()
-        }
+    var startValue by refreshOnUpdate(value, { this.value = it; refresh() })
     /**
      * The type of the generated HTML input element.
      */
-    var type: CHECKINPUTTYPE = type
-        set(value) {
-            field = value
-            refresh()
-        }
+    var type by refreshOnUpdate(type)
     /**
      * The name attribute of the generated HTML input element.
      */
-    var name: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var name: String? by refreshOnUpdate()
     /**
      * Determines if the field is disabled.
      */
-    var disabled: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var disabled by refreshOnUpdate(false)
     /**
      * The additional String value used for the radio button group.
      */
-    var extraValue: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var extraValue: String? by refreshOnUpdate()
     /**
      * The size of the input.
      */
-    var size: INPUTSIZE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var size: INPUTSIZE? by refreshOnUpdate()
 
     override fun render(): VNode {
         return render("input")
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/check/Radio.kt b/src/main/kotlin/pl/treksoft/kvision/form/check/Radio.kt
index ef5d6eb9..0cf85fc5 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/check/Radio.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/check/Radio.kt
@@ -117,27 +117,15 @@ open class Radio(
     /**
      * The style (one of Bootstrap standard colors) of the input.
      */
-    var style: RADIOSTYLE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var style: RADIOSTYLE? by refreshOnUpdate()
     /**
      * Determines if the radio button is rendered as a square.
      */
-    var squared: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var squared by refreshOnUpdate(false)
     /**
      * Determines if the radio button is rendered inline.
      */
-    var inline: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var inline by refreshOnUpdate(false)
     /**
      * The size of the input.
      */
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/check/RadioGroup.kt b/src/main/kotlin/pl/treksoft/kvision/form/check/RadioGroup.kt
index aa29de34..e5b04a47 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/check/RadioGroup.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/check/RadioGroup.kt
@@ -54,29 +54,17 @@ open class RadioGroup(
     /**
      * A list of options (label to value pairs) for the group.
      */
-    var options = options
-        set(value) {
-            field = value
-            setChildrenFromOptions()
-        }
+    var options by refreshOnUpdate(options, { setChildrenFromOptions() })
 
     /**
      * A value of the selected option.
      */
-    override var value = value
-        set(value) {
-            field = value
-            setValueToChildren(value)
-        }
+    override var value by refreshOnUpdate(value, { setValueToChildren(it) })
 
     /**
      * Determines if the options are rendered inline.
      */
-    var inline: Boolean = inline
-        set(value) {
-            field = value
-            refresh()
-        }
+    var inline by refreshOnUpdate(inline)
 
     override var disabled
         get() = getDisabledFromChildren()
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/select/SelectInput.kt b/src/main/kotlin/pl/treksoft/kvision/form/select/SelectInput.kt
index f90401ce..b0b7f4b3 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/select/SelectInput.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/select/SelectInput.kt
@@ -65,124 +65,68 @@ open class SelectInput(
     /**
      * A list of options (label to value pairs) for the select control.
      */
-    internal var options = options
-        set(value) {
-            field = value
-            setChildrenFromOptions()
-        }
+    internal var options by refreshOnUpdate(options, { setChildrenFromOptions() })
     /**
      * A value of the selected option.
      */
-    var value: String? = value
-        set(value) {
-            field = value
-            refreshState()
-        }
+    var value by refreshOnUpdate(value, { refreshState() })
     /**
      * The name attribute of the generated HTML select element.
      */
-    var name: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var name: String? by refreshOnUpdate()
     /**
      * Determines if multiple value selection is allowed.
      */
-    var multiple: Boolean = multiple
-        set(value) {
-            field = value
-            refresh()
-        }
+    var multiple by refreshOnUpdate(multiple)
     /**
      * Additional options for remote (AJAX) data source.
      */
-    var ajaxOptions: AjaxOptions? = ajaxOptions
-        set(value) {
-            field = value
-            if (value != null) liveSearch = true
-            refresh()
+    var ajaxOptions by refreshOnUpdate(ajaxOptions, {
+        if (it != null) {
+            liveSearch = true
         }
+        refresh()
+    })
     /**
      * Maximal number of selected options.
      */
-    var maxOptions: Int? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var maxOptions: Int? by refreshOnUpdate()
     /**
      * Determines if live search is available.
      */
-    var liveSearch: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var liveSearch by refreshOnUpdate(false)
     /**
      * The placeholder for the select control.
      */
-    var placeholder: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var placeholder: String? by refreshOnUpdate()
     /**
      * The style of the select control.
      */
-    var style: BUTTONSTYLE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var style: BUTTONSTYLE? by refreshOnUpdate()
     /**
      * The width of the select control.
      */
-    var selectWidth: CssSize? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var selectWidth: CssSize? by refreshOnUpdate()
     /**
      * The width type of the select control.
      */
-    var selectWidthType: SELECTWIDTHTYPE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var selectWidthType: SELECTWIDTHTYPE? by refreshOnUpdate()
     /**
      * Determines if an empty option is automatically generated.
      */
-    var emptyOption: Boolean = false
-        set(value) {
-            field = value
-            setChildrenFromOptions()
-        }
+    var emptyOption by refreshOnUpdate(false, { setChildrenFromOptions() })
     /**
      * Determines if the field is disabled.
      */
-    var disabled: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var disabled by refreshOnUpdate(false)
     /**
      * Determines if the select is automatically focused.
      */
-    var autofocus: Boolean? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var autofocus: Boolean? by refreshOnUpdate()
     /**
      * The size of the input.
      */
-    var size: INPUTSIZE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var size: INPUTSIZE? by refreshOnUpdate()
 
     init {
         setChildrenFromOptions()
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/select/SelectOptGroup.kt b/src/main/kotlin/pl/treksoft/kvision/form/select/SelectOptGroup.kt
index 6819961f..95d8f178 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/select/SelectOptGroup.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/select/SelectOptGroup.kt
@@ -45,35 +45,19 @@ open class SelectOptGroup(
     /**
      * A label for the group.
      */
-    var label: String = label
-        set(value) {
-            field = value
-            refresh()
-        }
+    var label by refreshOnUpdate(label)
     /**
      * A list of options (label to value pairs) for the group.
      */
-    var options = options
-        set(value) {
-            field = value
-            setChildrenFromOptions()
-        }
+    var options by refreshOnUpdate(options, { setChildrenFromOptions() })
     /**
      * Maximal number of selected options in the group.
      */
-    var maxOptions: Int? = maxOptions
-        set(value) {
-            field = value
-            refresh()
-        }
+    var maxOptions by refreshOnUpdate(maxOptions)
     /**
      * Determines if the group is disabled.
      */
-    var disabled: Boolean = disabled
-        set(value) {
-            field = value
-            refresh()
-        }
+    var disabled by refreshOnUpdate(disabled)
 
     init {
         setChildrenFromOptions()
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/select/SelectOption.kt b/src/main/kotlin/pl/treksoft/kvision/form/select/SelectOption.kt
index e7a49120..141eff28 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/select/SelectOption.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/select/SelectOption.kt
@@ -46,51 +46,27 @@ open class SelectOption(
     /**
      * The value of the option.
      */
-    var value: String? = value
-        set(value) {
-            field = value
-            refresh()
-        }
+    var value by refreshOnUpdate(value)
     /**
      * The label of the option.
      */
-    var label: String? = label
-        set(value) {
-            field = value
-            refresh()
-        }
+    var label by refreshOnUpdate(label)
     /**
      * The subtext after the label of the option.
      */
-    var subtext: String? = subtext
-        set(value) {
-            field = value
-            refresh()
-        }
+    var subtext by refreshOnUpdate(subtext)
     /**
      * The icon before the label of the option.
      */
-    var icon: String? = icon
-        set(value) {
-            field = value
-            refresh()
-        }
+    var icon by refreshOnUpdate(icon)
     /**
      * Determines if the option should be rendered as divider.
      */
-    var divider: Boolean = divider
-        set(value) {
-            field = value
-            refresh()
-        }
+    var divider by refreshOnUpdate(divider)
     /**
      * Determines if the option should be disabled.
      */
-    var disabled: Boolean = disabled
-        set(value) {
-            field = value
-            refresh()
-        }
+    var disabled by refreshOnUpdate(disabled)
 
     override fun render(): VNode {
         return if (!divider) {
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/spinner/SpinnerInput.kt b/src/main/kotlin/pl/treksoft/kvision/form/spinner/SpinnerInput.kt
index a3f72b75..a5565d2a 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/spinner/SpinnerInput.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/spinner/SpinnerInput.kt
@@ -97,119 +97,62 @@ open class SpinnerInput(
     /**
      * Spinner value.
      */
-    var value: Number? = value
-        set(value) {
-            field = value
-            refreshState()
-        }
+    var value by refreshOnUpdate(value, { refreshState() })
     /**
      * The value attribute of the generated HTML input element.
      *
      * This value is placed directly in generated HTML code, while the [value] property is dynamically
      * bound to the spinner input value.
      */
-    var startValue: Number? = value
-        set(value) {
-            field = value
-            this.value = value
-            refresh()
-        }
+    var startValue by refreshOnUpdate(value, { this.value = it; refresh() })
     /**
      * Minimal value.
      */
-    var min: Int = min
-        set(value) {
-            field = value
-            refreshSpinner()
-        }
+    var min by refreshOnUpdate(min, { refreshSpinner() })
     /**
      * Maximal value.
      */
-    var max: Int = max
-        set(value) {
-            field = value
-            refreshSpinner()
-        }
+    var max by refreshOnUpdate(max, { refreshSpinner() })
     /**
      * Step value.
      */
-    var step: Double = step
-        set(value) {
-            field = value
-            refreshSpinner()
-        }
+    var step by refreshOnUpdate(step, { refreshSpinner() })
     /**
      * Number of decimal digits value.
      */
-    var decimals: Int = decimals
-        set(value) {
-            field = value
-            refreshSpinner()
-        }
+    var decimals by refreshOnUpdate(decimals, { refreshSpinner() })
     /**
      * Spinner buttons type.
      */
-    var buttonsType: BUTTONSTYPE = buttonsType
-        set(value) {
-            field = value
-            refreshSpinner()
-        }
+    var buttonsType by refreshOnUpdate(buttonsType, { refreshSpinner() })
     /**
      * Spinner force rounding type.
      */
-    var forceType: FORCETYPE = forceType
-        set(value) {
-            field = value
-            refreshSpinner()
-        }
+    var forceType by refreshOnUpdate(forceType, { refreshSpinner() })
     /**
      * The placeholder for the spinner input.
      */
-    var placeholder: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var placeholder: String? by refreshOnUpdate()
     /**
      * The name attribute of the generated HTML input element.
      */
-    var name: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var name: String? by refreshOnUpdate()
     /**
      * Determines if the field is disabled.
      */
-    var disabled: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var disabled by refreshOnUpdate(false)
     /**
      * Determines if the spinner is automatically focused.
      */
-    var autofocus: Boolean? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var autofocus: Boolean? by refreshOnUpdate()
     /**
      * Determines if the spinner is read-only.
      */
-    var readonly: Boolean? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var readonly: Boolean? by refreshOnUpdate()
     /**
      * The size of the input.
      */
-    var size: INPUTSIZE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var size: INPUTSIZE? by refreshOnUpdate()
 
     private var siblings: JQuery? = null
 
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/text/AbstractTextInput.kt b/src/main/kotlin/pl/treksoft/kvision/form/text/AbstractTextInput.kt
index 17a6689b..8467dab8 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/text/AbstractTextInput.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/text/AbstractTextInput.kt
@@ -50,79 +50,42 @@ abstract class AbstractTextInput(
     /**
      * Text input value.
      */
-    var value: String? = value
-        set(value) {
-            field = value
-            refreshState()
-        }
+    var value by refreshOnUpdate(value, { refreshState() })
     /**
      * The value attribute of the generated HTML input element.
      *
      * This value is placed directly in generated HTML code, while the [value] property is dynamically
      * bound to the text input value.
      */
-    var startValue: String? = value
-        set(value) {
-            field = value
-            this.value = value
-            refresh()
-        }
+    var startValue by refreshOnUpdate(value, { this.value = it; refresh() })
     /**
      * The placeholder for the text input.
      */
-    var placeholder: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var placeholder: String? by refreshOnUpdate()
     /**
      * The name attribute of the generated HTML input element.
      */
-    var name: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var name: String? by refreshOnUpdate()
     /**
      * Maximal length of the text input value.
      */
-    var maxlength: Int? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var maxlength: Int? by refreshOnUpdate()
     /**
      * Determines if the field is disabled.
      */
-    var disabled: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var disabled by refreshOnUpdate(false)
     /**
      * Determines if the text input is automatically focused.
      */
-    var autofocus: Boolean? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var autofocus: Boolean? by refreshOnUpdate()
     /**
      * Determines if the text input is read-only.
      */
-    var readonly: Boolean? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var readonly: Boolean? by refreshOnUpdate()
     /**
      * The size of the input.
      */
-    var size: INPUTSIZE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var size: INPUTSIZE? by refreshOnUpdate()
 
     override fun getSnClass(): List<StringBoolPair> {
         val cl = super.getSnClass().toMutableList()
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/text/TextAreaInput.kt b/src/main/kotlin/pl/treksoft/kvision/form/text/TextAreaInput.kt
index 8ee150e1..9fc89544 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/text/TextAreaInput.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/text/TextAreaInput.kt
@@ -40,27 +40,15 @@ open class TextAreaInput(cols: Int? = null, rows: Int? = null, value: String? =
     /**
      * Number of columns.
      */
-    var cols: Int? = cols
-        set(value) {
-            field = value
-            refresh()
-        }
+    var cols by refreshOnUpdate(cols)
     /**
      * Number of rows.
      */
-    var rows: Int? = rows
-        set(value) {
-            field = value
-            refresh()
-        }
+    var rows by refreshOnUpdate(rows)
     /**
      * Determines if hard wrapping is enabled for the textarea element.
      */
-    var wrapHard: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var wrapHard by refreshOnUpdate(false)
 
     override fun render(): VNode {
         return startValue?.let {
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/text/TextInput.kt b/src/main/kotlin/pl/treksoft/kvision/form/text/TextInput.kt
index a2bfcd0b..998bfb2c 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/text/TextInput.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/text/TextInput.kt
@@ -52,19 +52,11 @@ open class TextInput(type: TEXTINPUTTYPE = TEXTINPUTTYPE.TEXT, value: String? =
     /**
      * Text input type.
      */
-    var type: TEXTINPUTTYPE = type
-        set(value) {
-            field = value
-            refresh()
-        }
+    var type by refreshOnUpdate(type)
     /**
      * Determines if autocomplete is enabled for the input element.
      */
-    var autocomplete: Boolean? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var autocomplete: Boolean? by refreshOnUpdate()
 
     override fun render(): VNode {
         return render("input")
diff --git a/src/main/kotlin/pl/treksoft/kvision/form/time/DateTimeInput.kt b/src/main/kotlin/pl/treksoft/kvision/form/time/DateTimeInput.kt
index c198ec77..3eeec789 100644
--- a/src/main/kotlin/pl/treksoft/kvision/form/time/DateTimeInput.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/form/time/DateTimeInput.kt
@@ -60,123 +60,63 @@ open class DateTimeInput(
     /**
      * Date/time input value.
      */
-    var value: Date? = value
-        set(value) {
-            field = value
-            refreshState()
-        }
+    var value by refreshOnUpdate(value, { refreshState() })
     /**
      * Date/time format.
      */
-    var format: String = format
-        set(value) {
-            field = value
-            refreshDatePicker()
-        }
+    var format by refreshOnUpdate(format, { refreshDatePicker() })
     /**
      * The placeholder for the date/time input.
      */
-    var placeholder: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var placeholder: String? by refreshOnUpdate()
     /**
      * The name attribute of the generated HTML input element.
      */
-    var name: String? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var name: String? by refreshOnUpdate()
     /**
      * Determines if the field is disabled.
      */
-    var disabled: Boolean = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var disabled by refreshOnUpdate(false)
     /**
      * Determines if the text input is automatically focused.
      */
-    var autofocus: Boolean? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var autofocus: Boolean? by refreshOnUpdate()
     /**
      * Determines if the date/time input is read-only.
      */
-    var readonly: Boolean? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var readonly: Boolean? by refreshOnUpdate()
     /**
      * The size of the input.
      */
-    var size: INPUTSIZE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var size: INPUTSIZE? by refreshOnUpdate()
     /**
      * Day of the week start. 0 (Sunday) to 6 (Saturday).
      */
-    var weekStart: Int = 0
-        set(value) {
-            field = value
-            refreshDatePicker()
-        }
+    var weekStart by refreshOnUpdate(0, { refreshDatePicker() })
     /**
      * Days of the week that should be disabled. Multiple values should be comma separated.
      */
-    var daysOfWeekDisabled: Array<Int> = arrayOf()
-        set(value) {
-            field = value
-            refreshDatePicker()
-        }
+    var daysOfWeekDisabled by refreshOnUpdate(arrayOf<Int>(), { refreshDatePicker() })
     /**
      * Determines if *Clear* button should be visible.
      */
-    var clearBtn: Boolean = true
-        set(value) {
-            field = value
-            refreshDatePicker()
-        }
+    var clearBtn by refreshOnUpdate(true, { refreshDatePicker() })
     /**
      * Determines if *Today* button should be visible.
      */
-    var todayBtn: Boolean = false
-        set(value) {
-            field = value
-            refreshDatePicker()
-        }
+    var todayBtn by refreshOnUpdate(false, { refreshDatePicker() })
     /**
      * Determines if the current day should be highlighted.
      */
-    var todayHighlight: Boolean = false
-        set(value) {
-            field = value
-            refreshDatePicker()
-        }
+    var todayHighlight by refreshOnUpdate(false, { refreshDatePicker() })
     /**
      * The increment used to build the hour view.
      */
-    var minuteStep: Int = DEFAULT_MINUTE_STEP
-        set(value) {
-            field = value
-            refreshDatePicker()
-        }
+    var minuteStep by refreshOnUpdate(DEFAULT_MINUTE_STEP, { refreshDatePicker() })
     /**
      * Determines if meridian views are visible in day and hour views.
      */
-    var showMeridian: Boolean = false
-        set(value) {
-            field = value
-            refreshDatePicker()
-        }
+    var showMeridian by refreshOnUpdate(false, { refreshDatePicker() })
 
     override fun render(): VNode {
         return render("input")
diff --git a/src/main/kotlin/pl/treksoft/kvision/html/Button.kt b/src/main/kotlin/pl/treksoft/kvision/html/Button.kt
index 79155395..e6f53737 100644
--- a/src/main/kotlin/pl/treksoft/kvision/html/Button.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/html/Button.kt
@@ -69,59 +69,31 @@ open class Button(
     /**
      * Button label.
      */
-    var text = text
-        set(value) {
-            field = value
-            refresh()
-        }
+    var text by refreshOnUpdate(text)
     /**
      * Button icon.
      */
-    var icon = icon
-        set(value) {
-            field = value
-            refresh()
-        }
+    var icon by refreshOnUpdate(icon)
     /**
      * Button style.
      */
-    var style = style
-        set(value) {
-            field = value
-            refresh()
-        }
+    var style by refreshOnUpdate(style)
     /**
      * Determines if button is disabled.
      */
-    var disabled = disabled
-        set(value) {
-            field = value
-            refresh()
-        }
+    var disabled by refreshOnUpdate(disabled)
     /**
      * Button image.
      */
-    var image: ResString? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var image: ResString? by refreshOnUpdate()
     /**
      * Button size.
      */
-    var size: BUTTONSIZE? = null
-        set(value) {
-            field = value
-            refresh()
-        }
+    var size: BUTTONSIZE? by refreshOnUpdate()
     /**
      * Determines if the button takes all the space horizontally.
      */
-    var block = false
-        set(value) {
-            field = value
-            refresh()
-        }
+    var block by refreshOnUpdate(false)
 
     override fun render(): VNode {
         val t = createLabelWithIcon(text, icon, image)
diff --git a/src/main/kotlin/pl/treksoft/kvision/html/Image.kt b/src/main/kotlin/pl/treksoft/kvision/html/Image.kt
index bd469afe..ac7829e8 100644
--- a/src/main/kotlin/pl/treksoft/kvision/html/Image.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/html/Image.kt
@@ -55,43 +55,23 @@ open class Image(
     /**
      * URL of the image.
      */
-    var src = src
-        set(value) {
-            field = value
-            refresh()
-        }
+    var src by refreshOnUpdate(src)
     /**
      * The alternative text of the image.
      */
-    var alt = alt
-        set(value) {
-            field = value
-            refresh()
-        }
+    var alt by refreshOnUpdate(alt)
     /**
      * Determines if the image is rendered as responsive.
      */
-    var responsive = responsive
-        set(value) {
-            field = value
-            refresh()
-        }
+    var responsive by refreshOnUpdate(responsive)
     /**
      * The shape of the image.
      */
-    var shape = shape
-        set(value) {
-            field = value
-            refresh()
-        }
+    var shape by refreshOnUpdate(shape)
     /**
      * Determines if the image is rendered as centered.
      */
-    var centered = centered
-        set(value) {
-            field = value
-            refresh()
-        }
+    var centered by refreshOnUpdate(centered)
 
     override fun render(): VNode {
         return render("img")
diff --git a/src/main/kotlin/pl/treksoft/kvision/html/Link.kt b/src/main/kotlin/pl/treksoft/kvision/html/Link.kt
index e075d685..94c7c594 100644
--- a/src/main/kotlin/pl/treksoft/kvision/html/Link.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/html/Link.kt
@@ -44,35 +44,19 @@ open class Link(
     /**
      * Link label.
      */
-    var label = label
-        set(value) {
-            field = value
-            refresh()
-        }
+    var label by refreshOnUpdate(label)
     /**
      * Link URL address.
      */
-    var url = url
-        set(value) {
-            field = value
-            refresh()
-        }
+    var url by refreshOnUpdate(url)
     /**
      * Link icon.
      */
-    var icon = icon
-        set(value) {
-            field = value
-            refresh()
-        }
+    var icon by refreshOnUpdate(icon)
     /**
      * Link image.
      */
-    var image = image
-        set(value) {
-            field = value
-            refresh()
-        }
+    var image by refreshOnUpdate(image)
 
     override fun render(): VNode {
         val t = createLabelWithIcon(label, icon, image)
diff --git a/src/main/kotlin/pl/treksoft/kvision/html/List.kt b/src/main/kotlin/pl/treksoft/kvision/html/List.kt
index 2dadd546..185d2eea 100644
--- a/src/main/kotlin/pl/treksoft/kvision/html/List.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/html/List.kt
@@ -61,27 +61,15 @@ open class ListTag(
     /**
      * List type.
      */
-    var type = type
-        set(value) {
-            field = value
-            refresh()
-        }
+    var type by refreshOnUpdate(type)
     /**
      * List of elements.
      */
-    var elements = elements
-        set(value) {
-            field = value
-            refresh()
-        }
+    var elements by refreshOnUpdate(elements)
     /**
      * Determines if [elements] can contain HTML code.
      */
-    var rich = rich
-        set(value) {
-            field = value
-            refresh()
-        }
+    var rich by refreshOnUpdate(rich)
 
     init {
         @Suppress("LeakingThis")
diff --git a/src/main/kotlin/pl/treksoft/kvision/html/Tag.kt b/src/main/kotlin/pl/treksoft/kvision/html/Tag.kt
index 62a647bc..a3b7f231 100644
--- a/src/main/kotlin/pl/treksoft/kvision/html/Tag.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/html/Tag.kt
@@ -98,35 +98,19 @@ open class Tag(
     /**
      * Tag type.
      */
-    var type = type
-        set(value) {
-            field = value
-            refresh()
-        }
+    var type by refreshOnUpdate(type)
     /**
      * Text content of the tag.
      */
-    var text = text
-        set(value) {
-            field = value
-            refresh()
-        }
+    var text by refreshOnUpdate(text)
     /**
      * Determines if [text] can contain HTML code.
      */
-    var rich = rich
-        set(value) {
-            field = value
-            refresh()
-        }
+    var rich by refreshOnUpdate(rich)
     /**
      * Text align.
      */
-    var align = align
-        set(value) {
-            field = value
-            refresh()
-        }
+    var align by refreshOnUpdate(align)
 
     init {
         @Suppress("LeakingThis")
diff --git a/src/main/kotlin/pl/treksoft/kvision/modal/Confirm.kt b/src/main/kotlin/pl/treksoft/kvision/modal/Confirm.kt
index 33512a7e..a3bb8d77 100644
--- a/src/main/kotlin/pl/treksoft/kvision/modal/Confirm.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/modal/Confirm.kt
@@ -75,11 +75,7 @@ open class Confirm(
     /**
      * Determines if Cancel button is visible.
      */
-    var cancelVisible = cancelVisible
-        set(value) {
-            field = value
-            refreshCancelButton()
-        }
+    var cancelVisible by refreshOnUpdate(cancelVisible, { refreshCancelButton() })
 
     private val content = Tag(TAG.DIV, text, rich, align)
     private val cancelButton = Button("Cancel", "remove")
diff --git a/src/main/kotlin/pl/treksoft/kvision/modal/Modal.kt b/src/main/kotlin/pl/treksoft/kvision/modal/Modal.kt
index f913fac1..d9cd0e8e 100644
--- a/src/main/kotlin/pl/treksoft/kvision/modal/Modal.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/modal/Modal.kt
@@ -89,11 +89,7 @@ open class Modal(
     /**
      * Determines if animations are used.
      */
-    var animation = animation
-        set(value) {
-            field = value
-            refresh()
-        }
+    var animation by refreshOnUpdate(animation)
 
     private val dialog = ModalDialog(size)
     private val header = SimplePanel(setOf("modal-header"))
@@ -260,11 +256,7 @@ internal class ModalDialog(size: MODALSIZE?) : SimplePanel(setOf("modal-dialog")
     /**
      * Modal window size.
      */
-    var size = size
-        set(value) {
-            field = value
-            refresh()
-        }
+    var size by refreshOnUpdate(size)
 
     override fun getSnClass(): List<StringBoolPair> {
         val cl = super.getSnClass().toMutableList()
diff --git a/src/main/kotlin/pl/treksoft/kvision/panel/FlexPanel.kt b/src/main/kotlin/pl/treksoft/kvision/panel/FlexPanel.kt
index e4e5dd47..3bb42d53 100644
--- a/src/main/kotlin/pl/treksoft/kvision/panel/FlexPanel.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/panel/FlexPanel.kt
@@ -104,53 +104,27 @@ open class FlexPanel(
     /**
      * CSS flexbox direction.
      */
-    var direction = direction
-        set(value) {
-            field = value
-            refreshSpacing()
-            refresh()
-        }
+    var direction by refreshOnUpdate(direction, { refreshSpacing(); refresh() })
     /**
      * CSS flexbox wrap mode.
      */
-    var wrap = wrap
-        set(value) {
-            field = value
-            refresh()
-        }
+    var wrap by refreshOnUpdate(wrap)
     /**
      * CSS flexbox content justification.
      */
-    var justify = justify
-        set(value) {
-            field = value
-            refresh()
-        }
+    var justify by refreshOnUpdate(justify)
     /**
      * CSS flexbox items alignment.
      */
-    var alignItems = alignItems
-        set(value) {
-            field = value
-            refresh()
-        }
+    var alignItems by refreshOnUpdate(alignItems)
     /**
      * CSS flexbox content alignment.
      */
-    var alignContent = alignContent
-        set(value) {
-            field = value
-            refresh()
-        }
+    var alignContent by refreshOnUpdate(alignContent)
     /**
      * The spacing between columns/rows.
      */
-    var spacing = spacing
-        set(value) {
-            field = value
-            refreshSpacing()
-            refresh()
-        }
+    var spacing by refreshOnUpdate(spacing, { refreshSpacing(); refresh() })
 
     init {
         @Suppress("LeakingThis")
diff --git a/src/main/kotlin/pl/treksoft/kvision/panel/GridPanel.kt b/src/main/kotlin/pl/treksoft/kvision/panel/GridPanel.kt
index 178c1e7f..10e956be 100644
--- a/src/main/kotlin/pl/treksoft/kvision/panel/GridPanel.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/panel/GridPanel.kt
@@ -112,99 +112,51 @@ open class GridPanel(
     /**
      * CSS grid auto columns.
      */
-    var autoColumns = autoColumns
-        set(value) {
-            field = value
-            refresh()
-        }
+    var autoColumns by refreshOnUpdate(autoColumns)
     /**
      * CSS grid auto rows.
      */
-    var autoRows = autoRows
-        set(value) {
-            field = value
-            refresh()
-        }
+    var autoRows by refreshOnUpdate(autoRows)
     /**
      * CSS grid auto flow.
      */
-    var autoFlow = autoFlow
-        set(value) {
-            field = value
-            refresh()
-        }
+    var autoFlow by refreshOnUpdate(autoFlow)
     /**
      * CSS grid columns template.
      */
-    var templateColumns = templateColumns
-        set(value) {
-            field = value
-            refresh()
-        }
+    var templateColumns by refreshOnUpdate(templateColumns)
     /**
      * CSS grid rows template.
      */
-    var templateRows = templateRows
-        set(value) {
-            field = value
-            refresh()
-        }
+    var templateRows by refreshOnUpdate(templateRows)
     /**
      * CSS grid areas template.
      */
-    var templateAreas = templateAreas
-        set(value) {
-            field = value
-            refresh()
-        }
+    var templateAreas by refreshOnUpdate(templateAreas)
     /**
      * CSS grid column gap.
      */
-    var columnGap = columnGap
-        set(value) {
-            field = value
-            refresh()
-        }
+    var columnGap by refreshOnUpdate(columnGap)
     /**
      * CSS grid row gap.
      */
-    var rowGap = rowGap
-        set(value) {
-            field = value
-            refresh()
-        }
+    var rowGap by refreshOnUpdate(rowGap)
     /**
      * CSS grid items justification.
      */
-    var justifyItems = justifyItems
-        set(value) {
-            field = value
-            refresh()
-        }
+    var justifyItems by refreshOnUpdate(justifyItems)
     /**
      * CSS grid items alignment.
      */
-    var alignItems = alignItems
-        set(value) {
-            field = value
-            refresh()
-        }
+    var alignItems by refreshOnUpdate(alignItems)
     /**
      * CSS grid content justification.
      */
-    var justifyContent = justifyContent
-        set(value) {
-            field = value
-            refresh()
-        }
+    var justifyContent by refreshOnUpdate(justifyContent)
     /**
      * CSS grid content alignment.
      */
-    var alignContent = alignContent
-        set(value) {
-            field = value
-            refresh()
-        }
+    var alignContent by refreshOnUpdate(alignContent)
 
     init {
         @Suppress("LeakingThis")
diff --git a/src/main/kotlin/pl/treksoft/kvision/panel/ResponsiveGridPanel.kt b/src/main/kotlin/pl/treksoft/kvision/panel/ResponsiveGridPanel.kt
index 4a82ed5b..a5b3d577 100644
--- a/src/main/kotlin/pl/treksoft/kvision/panel/ResponsiveGridPanel.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/panel/ResponsiveGridPanel.kt
@@ -62,11 +62,7 @@ open class ResponsiveGridPanel(
     /**
      * Text align of grid cells.
      */
-    var align = align
-        set(value) {
-            field = value
-            refreshRowContainers()
-        }
+    var align by refreshOnUpdate(align, { refreshRowContainers() })
 
     internal val map = mutableMapOf<Int, MutableMap<Int, WidgetParam>>()
     private var auto: Boolean = true
diff --git a/src/main/kotlin/pl/treksoft/kvision/panel/StackPanel.kt b/src/main/kotlin/pl/treksoft/kvision/panel/StackPanel.kt
index bac027fe..da41db9f 100644
--- a/src/main/kotlin/pl/treksoft/kvision/panel/StackPanel.kt
+++ b/src/main/kotlin/pl/treksoft/kvision/panel/StackPanel.kt
@@ -44,11 +44,7 @@ open class StackPanel(
     /**
      * The index of active (visible) child.
      */
-    var activeIndex = -1
-        set(value) {
-            field = value
-            refresh()
-        }
+    var activeIndex by refreshOnUpdate(-1)
 
     init {
         @Suppress("LeakingThis")
diff --git a/src/test/kotlin/test/pl/treksoft/kvision/html/ImageSpec.kt b/src/test/kotlin/test/pl/treksoft/kvision/html/ImageSpec.kt
index e44d4b44..45ea9eb0 100644
--- a/src/test/kotlin/test/pl/treksoft/kvision/html/ImageSpec.kt
+++ b/src/test/kotlin/test/pl/treksoft/kvision/html/ImageSpec.kt
@@ -37,6 +37,7 @@ class ImageSpec : DomSpec {
         run {
             val root = Root("test")
             val res = require("./img/placeholder.png")
+            @Suppress("UnsafeCastFromDynamic")
             val image = Image(res, "Image", true, IMAGESHAPE.ROUNDED, true)
             root.add(image)
             val element = document.getElementById("test")