cache time & garbage collection support added

onData & onError callbacks WIP

packages/example/lib/another_component.dart

@@ -7,7 +7,11 @@ class AnotherComponent extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final lol = QueryBowl.of(context).getQuery<String, void>("greetings");
+    final deadQuery =
+        QueryBowl.of(context).getQuery<String, String>("external_data");
     if (lol?.data == null) return const CircularProgressIndicator();
-    return Text("${lol!.data!} from AnotherComponent");
+    return Text(
+      "${lol!.data!} from AnotherComponent\nDeadQuery (It should be null after 10 seconds): ${deadQuery?.data}",
+    );
   }
 }

packages/example/lib/main.dart

@@ -30,15 +30,18 @@ class MyApp extends StatelessWidget {
 }
 
 final successJob = QueryJob<String, void>(
-    queryKey: "greetings",
-    task: (queryKey, _) => Future.delayed(const Duration(seconds: 2),
-        () => "Welcome ($queryKey) ${Random.secure().nextInt(100)}"));
+  queryKey: "greetings",
+  task: (queryKey, _) => Future.delayed(const Duration(seconds: 2),
+      () => "Welcome ($queryKey) ${Random.secure().nextInt(100)}"),
+);
 
 final failedJob = QueryJob<String, void>(
   queryKey: "failure",
   task: (queryKey, _) => Random().nextBool()
       ? Future.error("[$queryKey] Failed for unknown reason")
-      : Future.value("Success, you'll get slowly ${Random().nextInt(100)}!"),
+      : Future.value(
+          "Success, you'll get slowly ${Random().nextInt(100)}!",
+        ),
 );
 
 class MyHomePage extends StatefulWidget {
@@ -97,7 +100,8 @@ class _MyHomePageState extends State<MyHomePage> {
                     children: [
                       if (query.hasError)
                         Text(
-                            "${query.error}. Retrying: ${query.retryAttempts}"),
+                          "${query.error}. Retrying: ${query.retryAttempts}",
+                        ),
                       if (query.hasData)
                         Text(
                             "Success after ${query.retryAttempts}. Data: ${query.data}"),

packages/example/lib/query_with_external_data.dart

@@ -5,6 +5,7 @@ import 'package:flutter/material.dart';
 
 final jobWithExternalData = QueryJob<String, String>(
     queryKey: "external_data",
+    cacheTime: const Duration(seconds: 10),
     task: (queryKey, data) {
       return Future.delayed(const Duration(milliseconds: 500),
           () => "Hello from $queryKey with $data");