using valuekeys for keeping track of mounts in query & mutations

QueryBuilder & MutaionBuilder are now null proof

README.md

@@ -0,0 +1,3 @@
+# FL-Query
+
+Asynchronous data caching, refetching & invalidation library for Flutter. FL-Query lets you manage & distribute your data async data without touching any global state

packages/example/pubspec.lock

@@ -43,6 +43,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.16.0"
+  crypto:
+    dependency: transitive
+    description:
+      name: crypto
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "3.0.2"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -184,6 +191,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "1.3.1"
+  uuid:
+    dependency: transitive
+    description:
+      name: uuid
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "3.0.6"
   vector_math:
     dependency: transitive
     description:

packages/fl_query/lib/mutation.dart

@@ -34,7 +34,7 @@ class Mutation<T extends Object, V> extends ChangeNotifier {
   /// used for keeping track of mutation activity. If the are no mounts &
   /// the passed cached time is over than the mutation is removed from
   /// storage/cache
-  Set<Widget> _mounts = {};
+  Set<ValueKey<String>> _mounts = {};
 
   @protected
   final Set<MutationListener<T>> onDataListeners = {};
@@ -87,20 +87,20 @@ class Mutation<T extends Object, V> extends ChangeNotifier {
   bool get isInactive => _mounts.isEmpty;
   // all methods
 
-  void mount(Widget widget) {
+  void mount(ValueKey<String> uKey) {
-    _mounts.add(widget);
+    _mounts.add(uKey);
   }
 
-  void unmount(Widget widget) {
+  void unmount(ValueKey<String> uKey) {
     if (_mounts.length == 1) {
       Future.delayed(_cacheTime, () {
-        _mounts.remove(widget);
+        _mounts.remove(uKey);
         // for letting know QueryBowl that this one's time has come for
         // getting crushed
         notifyListeners();
       });
     } else {
-      _mounts.remove(widget);
+      _mounts.remove(uKey);
     }
   }
 

packages/fl_query/lib/mutation_builder.dart

@@ -1,6 +1,7 @@
 import 'package:fl_query/models/mutation_job.dart';
 import 'package:fl_query/mutation.dart';
 import 'package:fl_query/query_bowl.dart';
+import 'package:fl_query/utils.dart';
 import 'package:flutter/widgets.dart';
 
 class MutationBuilder<T extends Object, V> extends StatefulWidget {
@@ -36,38 +37,62 @@ class _MutationBuilderState<T extends Object, V>
     extends State<MutationBuilder<T, V>> {
   late QueryBowl queryBowl;
 
+  late ValueKey<String> uKey;
+
+  late Mutation<T, V> mutation;
+
   @override
   void initState() {
     super.initState();
+    uKey = ValueKey<String>(uuid.v4());
+    mutation = Mutation<T, V>.fromOptions(widget.job);
     WidgetsBinding.instance.addPostFrameCallback((_) {
       queryBowl = QueryBowl.of(context);
-      queryBowl.addMutation<T, V>(
+      mutation = queryBowl.addMutation<T, V>(
-        widget.job,
+        mutation,
         onData: widget.onData,
         onError: widget.onError,
         onMutate: widget.onMutate,
-        mount: widget,
+        key: uKey,
       );
     });
   }
 
+  @override
+  void didUpdateWidget(covariant MutationBuilder<T, V> oldWidget) {
+    if (oldWidget.onData != widget.onData && oldWidget.onData != null) {
+      mutation.onDataListeners.remove(oldWidget.onData);
+      if (widget.onData != null) mutation.onDataListeners.add(widget.onData!);
+    }
+    if (oldWidget.onError != widget.onError && oldWidget.onError != null) {
+      mutation.onErrorListeners.remove(oldWidget.onError);
+      if (widget.onError != null)
+        mutation.onErrorListeners.add(widget.onError!);
+    }
+    if (oldWidget.onMutate != widget.onMutate && oldWidget.onMutate != null) {
+      mutation.onMutateListeners.remove(oldWidget.onMutate);
+      if (widget.onMutate != null)
+        mutation.onMutateListeners.add(widget.onMutate!);
+    }
+    super.didUpdateWidget(oldWidget);
+  }
+
   @override
   void dispose() {
-    final mutation = queryBowl.getMutation(widget.job.mutationKey);
+    mutation.unmount(uKey);
-    mutation?.unmount(widget);
+    if (widget.onData != null) mutation.onDataListeners.remove(widget.onData);
-    if (widget.onData != null) mutation?.onDataListeners.remove(widget.onData);
     if (widget.onError != null)
-      mutation?.onErrorListeners.remove(widget.onError);
+      mutation.onErrorListeners.remove(widget.onError);
     if (widget.onMutate != null)
-      mutation?.onMutateListeners.remove(widget.onMutate);
+      mutation.onMutateListeners.remove(widget.onMutate);
     super.dispose();
   }
 
   @override
   Widget build(BuildContext context) {
     queryBowl = QueryBowl.of(context);
-    final mutation = queryBowl.getMutation<T, V>(widget.job.mutationKey);
+    final latestMutation =
-    if (mutation == null) return Container();
+        queryBowl.getMutation<T, V>(mutation.mutationKey) ?? mutation;
-    return widget.builder(context, mutation);
+    return widget.builder(context, latestMutation);
   }
 }

packages/fl_query/lib/query.dart

@@ -61,7 +61,7 @@ class Query<T extends Object, Outside> extends ChangeNotifier {
   /// used for keeping track of query activity. If the are no mounts &
   /// the passed cached time is over than the query is removed from
   /// storage/cache
-  Set<Widget> _mounts = {};
+  Set<ValueKey<String>> _mounts = {};
 
   Query({
     required this.queryKey,
@@ -123,20 +123,20 @@ class Query<T extends Object, Outside> extends ChangeNotifier {
 
   // all methods
 
-  void mount(Widget widget) {
+  void mount(ValueKey<String> uKey) {
-    _mounts.add(widget);
+    _mounts.add(uKey);
   }
 
-  void unmount(Widget widget) {
+  void unmount(ValueKey<String> uKey) {
     if (_mounts.length == 1) {
       Future.delayed(_cacheTime, () {
-        _mounts.remove(widget);
+        _mounts.remove(uKey);
         // for letting know QueryBowl that this one's time has come for
         // getting crushed
         notifyListeners();
       });
     } else {
-      _mounts.remove(widget);
+      _mounts.remove(uKey);
     }
   }
 

packages/fl_query/lib/query_bowl.dart

@@ -165,7 +165,7 @@ class QueryBowl extends InheritedWidget {
     required Outside externalData,
     final QueryListener<T>? onData,
     final QueryListener<dynamic>? onError,
-    Widget? mount,
+    required ValueKey<String> key,
   }) async {
     final prevQuery =
         _queries.firstWhereOrNull((q) => q.queryKey == options.queryKey);
@@ -174,7 +174,7 @@ class QueryBowl extends InheritedWidget {
       // changed
       final hasExternalDataChanged =
           prevQuery.prevUsedExternalData != externalData;
-      if (mount != null) prevQuery.mount(mount);
+      prevQuery.mount(key);
       if (onData != null) prevQuery.onDataListeners.add(onData);
       if (onError != null) prevQuery.onErrorListeners.add(onError);
       if (!prevQuery.hasData || hasExternalDataChanged) {
@@ -192,34 +192,56 @@ class QueryBowl extends InheritedWidget {
       onData: onData,
       onError: onError,
     );
-    if (mount != null) query.mount(mount);
+    query.mount(key);
     _addQuery<T, Outside>(query);
     return await query.fetch();
   }
 
-  void addMutation<T extends Object, V>(
+  Query<T, Outside> addQuery<T extends Object, Outside>(
-    MutationJob<T, V> options, {
+    Query<T, Outside> query, {
+    required ValueKey<String> key,
+    final QueryListener<T>? onData,
+    final QueryListener<dynamic>? onError,
+  }) {
+    final prevQuery =
+        _queries.firstWhereOrNull((q) => q.queryKey == query.queryKey);
+    if (prevQuery is Query<T, Outside>) {
+      // run the query if its still not called or if externalData has
+      // changed
+      if (prevQuery.prevUsedExternalData != query.externalData)
+        prevQuery.setExternalData(query.externalData);
+      prevQuery.mount(key);
+      if (onData != null) prevQuery.onDataListeners.add(onData);
+      if (onError != null) prevQuery.onErrorListeners.add(onError);
+      // mounting the widget that is using the query in the prevQuery
+      return prevQuery;
+    }
+    if (onData != null) query.onDataListeners.add(onData);
+    if (onError != null) query.onErrorListeners.add(onError);
+    query.mount(key);
+    _addQuery<T, Outside>(query);
+    return query;
+  }
+
+  Mutation<T, V> addMutation<T extends Object, V>(
+    Mutation<T, V> mutation, {
     final MutationListener<T>? onData,
     final MutationListener<dynamic>? onError,
     final MutationListener<V>? onMutate,
-    Widget? mount,
+    required ValueKey<String> key,
   }) {
     final prevMutation = _mutations.firstWhereOrNull(
-        (mutation) => mutation.mutationKey == options.mutationKey);
+        (prevMutation) => prevMutation.mutationKey == mutation.mutationKey);
     if (prevMutation != null && prevMutation is Mutation<T, V>) {
       if (onData != null) prevMutation.onDataListeners.add(onData);
       if (onError != null) prevMutation.onErrorListeners.add(onError);
       if (onMutate != null) prevMutation.onMutateListeners.add(onMutate);
-      if (mount != null) prevMutation.mount(mount);
+      prevMutation.mount(key);
+      return prevMutation;
     } else {
-      final mutation = Mutation.fromOptions(
+      mutation.mount(key);
-        options,
-        onData: onData,
-        onError: onError,
-        onMutate: onMutate,
-      );
-      if (mount != null) mutation.mount(mount);
       _addMutation(mutation);
+      return mutation;
     }
   }
 

packages/fl_query/lib/query_builder.dart

@@ -1,6 +1,7 @@
 import 'package:fl_query/models/query_job.dart';
 import 'package:fl_query/query.dart';
 import 'package:fl_query/query_bowl.dart';
+import 'package:fl_query/utils.dart';
 import 'package:flutter/widgets.dart';
 
 class QueryBuilder<T extends Object, Outside> extends StatefulWidget {
@@ -32,54 +33,63 @@ class QueryBuilder<T extends Object, Outside> extends StatefulWidget {
 class _QueryBuilderState<T extends Object, Outside>
     extends State<QueryBuilder<T, Outside>> {
   late QueryBowl queryBowl;
+  late final ValueKey<String> uKey;
+  late Query<T, Outside> query;
 
   @override
   void initState() {
     super.initState();
+    uKey = ValueKey<String>(uuid.v4());
+    query = Query<T, Outside>.fromOptions(
+      widget.job,
+      externalData: widget.externalData,
+    );
     WidgetsBinding.instance.addPostFrameCallback((_) async {
-      queryBowl = QueryBowl.of(context);
+      query = QueryBowl.of(context).addQuery<T, Outside>(
-      await queryBowl.fetchQuery<T, Outside>(
+        query,
-        widget.job,
+        key: uKey,
-        externalData: widget.externalData,
         onData: widget.onData,
         onError: widget.onError,
-        mount: widget,
       );
+      await query.fetch();
     });
   }
 
   @override
   void didUpdateWidget(covariant oldWidget) {
     if (oldWidget.externalData != widget.externalData) {
-      queryBowl = QueryBowl.of(context);
+      QueryBowl.of(context).fetchQuery(
-      // clearing up the old widget before adding the new updated one
-      // so unmounted zombie widgets don't get piled up
-      queryBowl.getQuery(widget.job.queryKey)?.unmount(oldWidget);
-      queryBowl.fetchQuery(
         widget.job,
         externalData: widget.externalData,
         onData: widget.onData,
         onError: widget.onError,
-        mount: widget,
+        key: uKey,
       );
+    } else {
+      if (oldWidget.onData != widget.onData && oldWidget.onData != null) {
+        query.onDataListeners.remove(oldWidget.onData);
+        if (widget.onData != null) query.onDataListeners.add(widget.onData!);
+      }
+      if (oldWidget.onError != widget.onError && oldWidget.onError != null) {
+        query.onErrorListeners.remove(oldWidget.onError);
+        if (widget.onError != null) query.onErrorListeners.add(widget.onError!);
+      }
     }
     super.didUpdateWidget(oldWidget);
   }
 
   @override
   void dispose() {
-    final query = queryBowl.getQuery(widget.job.queryKey);
+    query.unmount(uKey);
-    query?.unmount(widget);
+    if (widget.onData != null) query.onDataListeners.remove(widget.onData);
-    if (widget.onData != null) query?.onDataListeners.remove(widget.onData);
+    if (widget.onError != null) query.onErrorListeners.remove(widget.onError);
-    if (widget.onError != null) query?.onErrorListeners.remove(widget.onError);
     super.dispose();
   }
 
   @override
   Widget build(BuildContext context) {
     queryBowl = QueryBowl.of(context);
-    final query = queryBowl.getQuery<T, Outside>(widget.job.queryKey);
+    final latestQuery = queryBowl.getQuery<T, Outside>(query.queryKey) ?? query;
-    if (query == null) return Container();
+    return widget.builder(context, latestQuery);
-    return widget.builder(context, query);
   }
 }

packages/fl_query/lib/utils.dart

@@ -1,4 +1,5 @@
 import 'package:fl_query/query.dart';
+import 'package:uuid/uuid.dart';
 
 Future<void> callQueryListeners<T>(Set<QueryListener<T>> listeners, T data) {
   return Future.wait(listeners.map(
@@ -8,3 +9,5 @@ Future<void> callQueryListeners<T>(Set<QueryListener<T>> listeners, T data) {
   //   await listener(data);
   // }
 }
+
+const uuid = Uuid();

packages/fl_query/pubspec.yaml

@@ -12,6 +12,7 @@ dependencies:
   collection: ^1.16.0
   flutter:
     sdk: flutter
+  uuid: ^3.0.6
 
 dev_dependencies:
   flutter_test: