Add StateKey #461

lib/src/redux_adapter/adapter.dart

@@ -15,7 +15,7 @@ abstract class Adapter<T> extends Logic<T> implements AbstractAdapter<T> {
     ReducerFilter<T> filter,
     Effect<T> effect,
     Dependencies<T> dependencies,
-    Object Function(T) key,
+    @deprecated Object Function(T) key,
   })  : assert(adapter != null),
         assert(dependencies?.adapter == null,
             'Unexpected dependencies.list for Adapter.'),
@@ -25,6 +25,7 @@ abstract class Adapter<T> extends Logic<T> implements AbstractAdapter<T> {
           filter: filter,
           effect: effect,
           dependencies: dependencies,
+          // ignore:deprecated_member_use_from_same_package
           key: key,
         );
 

lib/src/redux_adapter/dynamic_flow_adapter.dart

@@ -6,12 +6,12 @@ import '../utils/utils.dart';
 import 'recycle_context.dart';
 
 class ItemBean {
-  String type;
-  Object data;
+  final String type;
+  final Object data;
 
-  ItemBean(this.type, this.data);
+  const ItemBean(this.type, this.data);
 
-  ItemBean clone() => ItemBean(type, data);
+  ItemBean clone({String type, Object data}) => ItemBean(type, data);
 }
 
 /// template is a map, driven by array
@@ -25,12 +25,19 @@ class DynamicFlowAdapter<T> extends Logic<T> with RecycleContextMixin<T> {
     ReducerFilter<T> filter,
     Reducer<T> reducer,
     Effect<T> effect,
-    Object Function(T) key,
+
+    /// implement [StateKey] in T instead of using key in Logic.
+    /// class T implements StateKey {
+    ///   Object _key = UniqueKey();
+    ///   Object key() => _key;
+    /// }
+    @deprecated Object Function(T) key,
   }) : super(
           reducer: _dynamicReducer(reducer, pool, connector),
           effect: effect,
           filter: filter,
           dependencies: null,
+          // ignore:deprecated_member_use_from_same_package
           key: key,
         );
 
@@ -100,7 +107,7 @@ Reducer<T> _dynamicReducer<T>(
         final Object newData = result.onReducer(itemBean.data, action);
         if (newData != itemBean.data) {
           copy ??= state.toList();
-          copy[i] = itemBean.clone()..data = newData;
+          copy[i] = itemBean.clone(data: newData);
         }
       }
     }
@@ -121,39 +128,35 @@ Reducer<T> _dynamicReducer<T>(
 /// frame. in this time the sub component will use cache state.
 Get<Object> _subGetter(Get<List<ItemBean>> getter, int index) {
   final List<ItemBean> curState = getter();
-  final Object subCache = curState[index].data;
+  ItemBean cacheItem = curState[index];
+
   return () {
     final List<ItemBean> newState = getter();
 
     /// Either all sub-components use cache or not.
-    if (_isSimilar(curState, newState)) {
-      return newState[index].data;
-    } else {
-      return subCache;
+    if (newState != null && newState.length > index) {
+      final ItemBean newItem = newState[index];
+      if (_couldReuse(cacheItem, newItem)) {
+        cacheItem = newItem;
+      }
     }
+
+    return cacheItem.data;
   };
 }
 
-/// Judge [oldList] and [newList] is similar
-///
-/// if true: means the list size and every itemBean type & data.runtimeType
-/// is equal.
-bool _isSimilar(
-  List<ItemBean> oldList,
-  List<ItemBean> newList,
-) {
-  if (oldList != newList &&
-      oldList?.length == newList.length &&
-      Collections.isNotEmpty(newList)) {
-    bool isEvery = true;
-    for (int i = 0; i < newList.length; i++) {
-      if (oldList[i].type != newList[i].type ||
-          oldList[i].data.runtimeType != newList[i].data.runtimeType) {
-        isEvery = false;
-        break;
-      }
-    }
-    return isEvery;
+bool _couldReuse(ItemBean beanA, ItemBean beanB) {
+  if (beanA.type != beanB.type) {
+    return false;
   }
-  return false;
+
+  final Object dataA = beanA.data;
+  final Object dataB = beanB.data;
+  if (dataA.runtimeType != dataB.runtimeType) {
+    return false;
+  }
+
+  final Object keyA = dataA is StateKey ? dataA.key() : null;
+  final Object keyB = dataB is StateKey ? dataB.key() : null;
+  return keyA == keyB;
 }

lib/src/redux_adapter/static_flow_adapter.dart

@@ -16,7 +16,13 @@ class StaticFlowAdapter<T> extends Logic<T>
     Reducer<T> reducer,
     Effect<T> effect,
     ReducerFilter<T> filter,
-    Object Function(T) key,
+
+    /// implement [StateKey] in T instead of using key in Logic.
+    /// class T implements StateKey {
+    ///   Object _key = UniqueKey();
+    ///   Object key() => _key;
+    /// }
+    @deprecated Object Function(T) key,
   })  : assert(slots != null),
         _slots = Collections.compact(slots),
         super(
@@ -31,6 +37,7 @@ class StaticFlowAdapter<T> extends Logic<T>
           effect: effect,
           filter: filter,
           dependencies: null,
+          // ignore:deprecated_member_use_from_same_package
           key: key,
         );
 

lib/src/redux_component/basic.dart

@@ -327,7 +327,17 @@ abstract class AbstractAdapter<T> implements AbstractLogic<T> {
 /// When a reducer is slow to handle an action, maybe we should use ReducerFilter to improve the performance.
 typedef ReducerFilter<T> = bool Function(T state, Action action);
 
-///
+/// implement [StateKey] in T .
+/// class T implements StateKey {
+///   Object _key = UniqueKey();
+///   Object key() => _key;
+/// }
+/// see [https://github.com/alibaba/fish-redux/issues/461]
+abstract class StateKey {
+  Object key();
+}
+
+/// Define a DispatchBus
 abstract class DispatchBus {
   void attach(DispatchBus parent);
 

lib/src/redux_component/component.dart

@@ -32,7 +32,13 @@ abstract class Component<T> extends Logic<T> implements AbstractComponent<T> {
     Dependencies<T> dependencies,
     ShouldUpdate<T> shouldUpdate,
     WidgetWrapper wrapper,
-    Key Function(T) key,
+
+    /// implement [StateKey] in T instead of using key in Logic.
+    /// class T implements StateKey {
+    ///   Object _key = UniqueKey();
+    ///   Object key() => _key;
+    /// }
+    @deprecated Key Function(T) key,
     bool clearOnDependenciesChanged = false,
   })  : assert(view != null),
         _view = view,
@@ -44,6 +50,7 @@ abstract class Component<T> extends Logic<T> implements AbstractComponent<T> {
           filter: filter,
           effect: effect,
           dependencies: dependencies,
+          // ignore:deprecated_member_use_from_same_package
           key: key,
         );
 

lib/src/redux_component/logic.dart

@@ -33,12 +33,25 @@ abstract class Logic<T> implements AbstractLogic<T> {
     Dependencies<T> dependencies,
     ReducerFilter<T> filter,
     Effect<T> effect,
-    Object Function(T state) key,
+
+    /// implement [StateKey] in T instead of using key in Logic.
+    /// class T implements StateKey {
+    ///   Object _key = UniqueKey();
+    ///   Object key() => _key;
+    /// }
+    @deprecated Object Function(T state) key,
   })  : _reducer = reducer,
         _filter = filter,
         _effect = effect,
         _dependencies = dependencies,
-        _key = key;
+        // ignore:deprecated_member_use_from_same_package
+        assert(isAssignFrom<T, StateKey>() == false || key == null,
+            'Implements [StateKey] in T instead of using key in Logic.'),
+        _key = isAssignFrom<T, StateKey>()
+            // ignore:avoid_as
+            ? ((T state) => (state as StateKey).key())
+            // ignore:deprecated_member_use_from_same_package
+            : key;
 
   @override
   Type get propertyType => T;
@@ -47,6 +60,8 @@ abstract class Logic<T> implements AbstractLogic<T> {
 
   bool isTypeof<K>() => Tuple0<T>() is Tuple0<K>;
 
+  static bool isAssignFrom<P, Q>() => Tuple0<P>() is Tuple0<Q>;
+
   /// if
   /// _resultCache['key'] = null;
   /// then

lib/src/redux_component/page.dart

@@ -34,7 +34,13 @@ abstract class Page<T, P> extends Component<T> {
     Dependencies<T> dependencies,
     ShouldUpdate<T> shouldUpdate,
     WidgetWrapper wrapper,
-    Key Function(T) key,
+
+    /// implement [StateKey] in T instead of using key in Logic.
+    /// class T implements StateKey {
+    ///   Object _key = UniqueKey();
+    ///   Object key() => _key;
+    /// }
+    @deprecated Key Function(T) key,
     List<Middleware<T>> middleware,
     List<ViewMiddleware<T>> viewMiddleware,
     List<EffectMiddleware<T>> effectMiddleware,
@@ -55,6 +61,7 @@ abstract class Page<T, P> extends Component<T> {
           effect: effect,
           shouldUpdate: shouldUpdate,
           wrapper: wrapper,
+          // ignore:deprecated_member_use_from_same_package
           key: key,
         );