cleanup and implementation of OnChange

Documentation~/ui.lithium.md

@@ -87,6 +87,7 @@ To make it easier to use, `ComponentStateExtensions` provides a couple of method
 * `MutableList<T> RememberList<T>(Func<IEnumerable<T>> factory)` - same as `RememberList(IEnumerable<T>)`, but uses `factory` to create initial value on first render.
 * `MutableDictionary<TKey, TValue> RememberDictionary(IDictionary<TKey, TValue> dictionary = null)` - same as `Remember`, but stores dictionary instead of single value.
 * `MutableDictionary<TKey, TValue> RememberDictionary(Func<IDictionary<TKey, TValue>> factory)` - same as `RememberDictionary(IDictionary<TKey, TValue>)`, but uses `factory` to create initial value of first render.
+* `T Cache<T>(Func<T> factory, params object[] vars)` - uses `factory` to create value, only recalculates when content of vars changes between renders.
 
 ### Callbacks
 
@@ -95,6 +96,7 @@ Available callback:
 * `void OnInit(Action onInit)` - calls `onInit` on first render.
 * `void OnDestroy(Action onDestroy)` - calls `onDestroy` before component is destroyed.
 * `void OnInit(Func<Action> onInit)` - calls `onInit` on first render and then calls value returned by it before component is destroyed.
+* `void OnChange(Action onChanged, params object[] vars)` - calls `onChanged` during render when any item of the `vars` array is not equal to corresponding item of `vars` from previous render. Can be used to call action when any of the dependencies changes.
 
 ### Contexts
 

Editor/Debugging/Debugger.cs

@@ -178,7 +178,7 @@ private static IComponent ValueInspector(object value) => WithState(() =>
         {
             //TODO: https://docs.unity3d.com/6000.0/Documentation/Manual/UIE-runtime-binding-define-data-source.html
             //TODO: use above guide to show editor for custom types without creating ScriptableObject instance
-            var property = UseMemo(() =>
+            var property = Cache(() =>
             {
                 var instance = CreateInstance<GenericProperty>();
 
@@ -216,7 +216,7 @@ private static IComponent RenderNode(CompositionContext.InspectedNode node, int
 
             var children = node.Children;
 
-            // NOTE: for some reason ui toolkit has a bug where height calculations are incorrect without wrapping element
+            //NOTE: for some reason ui toolkit has a bug where height calculations are incorrect without wrapping element
             return Box(Switch(children.Count == 0, () =>
                 Text(name, manipulators: new Clickable(OnSelected))
                     .WithStyle(new(flexGrow: 1, padding: new(left: offset)))

README.md

@@ -91,10 +91,11 @@ V1 roadmap:
 
 V2 roadmap:
 
-- [ ] implement `useMemo` / `useEffect` equivalent from ReactJS
+- [x] implement `useMemo` equivalent from ReactJS(`Cache`)
+- [x] implement `useEffect` equivalent from ReactJS(`OnUpdate`)
 - [x] rework methods for inspecting composition context
-- [ ] fully featured layout debugger with support for modifying variables and handling contexts
-- [ ] async handling to make working with network resources and files easier
+- [x] fully featured layout debugger with support for modifying variables and handling contexts
+- [x] basic async handling to make working with network resources and files easier
 - [x] remove/hide OnRender event from `IComponent`
 - [x] ensure support for unity tailwind
 - [x] component for stylesheet loading
@@ -103,11 +104,12 @@ Future releases:
 
 - [ ] optimization of styling system
 - [ ] support for named variables
-- [ ] pooling of `VisualElement`
+- [ ] global pooling of `VisualElement`s
 - [ ] pooling of components
 - [ ] further caching optimizations
 - [ ] visual ui builder
 - [ ] static style extraction
+- [ ] better async handling with tasks that can report status
 
 ## UI Elements interoperability
 

Runtime/Async/Async.cs

@@ -16,7 +16,7 @@ public class AsyncMutable<T> : IMutableValue
             public bool HasError => task.IsFaulted;
             public bool HasResult => task.IsCompletedSuccessfully;
 
-            public T Result => HasResult ? task.Result : throw new Exception("Value not ready!");
+            public T Result => HasResult ? task.Result : throw new("Value not ready!");
             public Exception Error => HasError ? task.Exception : null;
 
             [NotNull] private readonly Task<T> task;

Runtime/ComponentState.cs

@@ -104,20 +104,34 @@ public static void OnDestroy([NotNull] Action onDestroy) =>
 
         public static T UseContext<T>() => Ctx.UseContext<T>();
 
-        public static T UseMemo<T>(CompositionContext.FactoryDelegate<T> factory, params object[] vars)
+        public static T Cache<T>([NotNull] CompositionContext.FactoryDelegate<T> factory, params object[] vars)
         {
             var c = Ctx;
             var oldVars = c.RememberRef(vars);
             var oldResult = RememberRefF(factory);
 
-            if (oldVars.Value.Length != vars.Length || !oldVars.Value.Zip(vars, Equals).All(v => v))
-            {
-                oldResult.Value = factory();
-                oldVars.Value = vars;
-            }
+            if (oldVars.Value.Length == vars.Length && oldVars.Value.Zip(vars, Equals).All(v => v))
+                return oldResult.Value;
 
+            oldResult.Value = factory();
+            oldVars.Value = vars;
+
             return oldResult.Value;
         }
+
+        public static void OnChange([NotNull] Action onChanged, params object[] vars)
+        {
+            var c = Ctx;
+            var oldVars = c.RememberRef(vars);
+            // during first render, oldVars == vars is always true, so we compensate for that with OnInit
+            c.OnInit(onChanged);
+
+            if (oldVars.Value.Length == vars.Length && oldVars.Value.Zip(vars, Equals).All(v => v))
+                return;
+
+            oldVars.Value = vars;
+            onChanged.Invoke();
+        }
     }
 
     [PublicAPI]

package.json

@@ -1,9 +1,9 @@
 {
   "name": "com.niikelion.ui.lithium",
-  "version": "1.2.0",
+  "version": "2.0.0",
   "displayName": "Lithium UI",
   "description": "Reactive UI library designed for editor tools creation.",
-  "unity": "2023.1",
+  "unity": "6000.0",
   "keywords": [
     "ui", "lithium", "reactive", "ui-toolkit"
   ],