query reusability by QueryJob

QueryJob.task External Data Support
Query task is now pure function
Query.data is non-nullable (even the type)

packages/example/lib/another_component.dart

@@ -6,7 +6,7 @@ class AnotherComponent extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final lol = QueryBowl.of(context).getQuery<String>("greetings");
+    final lol = QueryBowl.of(context).getQuery<String, void>("greetings");
     if (lol?.data == null) return const CircularProgressIndicator();
     return Text("${lol!.data!} from AnotherComponent");
   }

packages/example/lib/main.dart

@@ -1,8 +1,8 @@
 import 'dart:math';
 
 import 'package:example/another_component.dart';
-import 'package:fl_query/query_bowl.dart';
-import 'package:fl_query/query_builder.dart';
+import 'package:example/query_with_external_data.dart';
+import 'package:fl_query/fl_query.dart';
 import 'package:flutter/material.dart';
 import 'dart:async';
 
@@ -15,19 +15,29 @@ class MyApp extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
-      title: 'Flutter Demo',
-      theme: ThemeData(
-        primarySwatch: Colors.blue,
-      ),
-      home: const QueryBowlScope(
-        staleTime: Duration(seconds: 10),
-        child: MyHomePage(),
+    return QueryBowlScope(
+      child: MaterialApp(
+        title: 'Flutter Demo',
+        theme: ThemeData(
+          useMaterial3: true,
+          primarySwatch: Colors.blue,
+        ),
+        home: const MyHomePage(),
       ),
     );
   }
 }
 
+final successJob = QueryJob<String, void>(
+    queryKey: "greetings",
+    task: (queryKey, _) => Future.delayed(const Duration(seconds: 2),
+        () => "Welcome ($queryKey) ${Random.secure().nextInt(100)}"));
+
+final failedJob = QueryJob<String, void>(
+  queryKey: "failure",
+  task: (queryKey, _) => Future.value("[$queryKey] Failed for unknown reason"),
+);
+
 class MyHomePage extends StatefulWidget {
   const MyHomePage({Key? key}) : super(key: key);
 
@@ -46,12 +56,9 @@ class _MyHomePageState extends State<MyHomePage> {
         children: [
           Row(
             children: [
-              QueryBuilder<String>(
-                queryKey: "greetings",
-                task: (queryKey) => Future.delayed(
-                    const Duration(seconds: 2),
-                    () =>
-                        "Welcome ($queryKey) ${Random.secure().nextInt(100)}"),
+              QueryBuilder<String, void>(
+                job: successJob,
+                externalData: null,
                 builder: (context, query) {
                   if (query.isLoading || query.isRefetching) {
                     return const CircularProgressIndicator();
@@ -64,10 +71,24 @@ class _MyHomePageState extends State<MyHomePage> {
                   );
                 },
               ),
-              QueryBuilder(
-                queryKey: "failure",
-                task: (queryKey) =>
-                    Future.value("[$queryKey] Failed for unknown reason"),
+              QueryBuilder<String, void>(
+                job: successJob,
+                externalData: null,
+                builder: (context, query) {
+                  if (query.isLoading || query.isRefetching) {
+                    return const CircularProgressIndicator();
+                  }
+                  return ElevatedButton(
+                    child: Text(query.data!),
+                    onPressed: () async {
+                      await query.refetch();
+                    },
+                  );
+                },
+              ),
+              QueryBuilder<String, void>(
+                job: failedJob,
+                externalData: null,
                 builder: (context, query) {
                   if (query.hasError) return Text(query.error);
                   return Text("Failure. You're a failure ${query.data}");
@@ -75,6 +96,16 @@ class _MyHomePageState extends State<MyHomePage> {
               ),
             ],
           ),
+          ElevatedButton(
+            child: const Text("External Data Example"),
+            onPressed: () {
+              Navigator.of(context).push(
+                MaterialPageRoute(
+                  builder: (context) => const QueryWithExternalData(),
+                ),
+              );
+            },
+          ),
           const AnotherComponent(),
         ],
       ),

packages/example/lib/query_with_external_data.dart

@@ -0,0 +1,39 @@
+import 'dart:math';
+
+import 'package:fl_query/fl_query.dart';
+import 'package:flutter/material.dart';
+
+final jobWithExternalData = QueryJob<String, String>(
+    queryKey: "external_data",
+    task: (queryKey, data) {
+      return Future.delayed(const Duration(milliseconds: 500),
+          () => "Hello from $queryKey with $data");
+    });
+
+class QueryWithExternalData extends StatelessWidget {
+  const QueryWithExternalData({Key? key}) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(),
+      body: QueryBuilder<String, String>(
+        job: jobWithExternalData,
+        externalData: (Random().nextDouble() * 200).toString(),
+        builder: (context, query) {
+          if (query.isLoading || query.isLoading || query.data == null) {
+            return const CircularProgressIndicator();
+          }
+          return Container(
+            width: double.parse(query.externalData),
+            height: double.parse(query.externalData),
+            decoration: const BoxDecoration(
+              shape: BoxShape.circle,
+              color: Colors.blue,
+            ),
+          );
+        },
+      ),
+    );
+  }
+}