add RefreshBuilder

lib/models/entities/PagedResult.dart

@@ -0,0 +1,23 @@
+
+class PagedResult {
+  num total;
+  num size;
+  num pages;
+  num current;
+  List<dynamic>? records;
+
+  PagedResult({
+    required this.total,
+    required this.size,
+    required this.pages,
+    required this.current,
+    this.records,
+  });
+
+  PagedResult.fromJson(Map<String, dynamic> json)
+    : total = json['total'],
+        size = json['size'],
+        pages = json['pages'],
+        current = json['current'],
+        records = json['records'];
+}

lib/widgets/Refresher.dart

@@ -0,0 +1,69 @@
+
+import 'package:farmer_client/models/entities/PagedResult.dart';
+import 'package:flutter/material.dart';
+
+class RefreshBuilder extends StatefulWidget {
+  RefreshBuilder({
+    Key? key,
+    required this.builder,
+    required this.fetch,
+    required this.useState,
+    this.onError,
+  }): super(key: key);
+
+  Future Function(Map param) fetch;
+  Function({PagedResult state, void Function(VoidCallback) setState}) useState;
+  Function? onError;
+
+  Widget Function({
+    BuildContext context,
+    Widget Function(Widget) reactor,
+    Function toggle,
+    PagedResult Function() result,
+    List<dynamic> listData,
+  }) builder;
+
+  @override
+  State<StatefulWidget> createState() => _RefresherState();
+}
+
+class _RefresherState extends State<RefreshBuilder> {
+
+  PagedResult result = PagedResult(total: 0, size: 0, pages: 0, current: 0);
+  List<dynamic> listData = [];
+  void Function(void Function())? _subSetState;
+
+  @override
+  initState() {
+    super.initState();
+    fetchData();
+  }
+
+  Future fetchData() {
+    return Future.value(widget.fetch({ "pageNum": 1 }).then((res) {
+      final pagedResult = PagedResult.fromJson(res);
+      widget.useState(state: pagedResult, setState: setState);
+    }).catchError((err) {
+      print(err);
+      if (null != widget.onError) {
+        widget.onError!(err);
+      }
+    }));
+  }
+
+  toggle() {
+    fetchData();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return RefreshIndicator(
+      triggerMode: RefreshIndicatorTriggerMode.onEdge,
+      onRefresh: fetchData,
+      child: widget.builder(
+          context: context,
+          toggle: toggle
+      ),
+    );
+  }
+}