page_state_builder 0.0.1

A Flutter package that helps manage loading, success, and error states in your UI with customizable builders.

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:example/responsive_page_wrapper.dart';
import 'package:get/get.dart';
import 'package:page_state_builder/page_state_builder.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'PageStateBuilder Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(
          seedColor: Colors.blue,
          brightness: Brightness.light,
        ),
        useMaterial3: true,
      ),
      darkTheme: ThemeData(
        colorScheme: ColorScheme.fromSeed(
          seedColor: Colors.blue,
          brightness: Brightness.dark,
        ),
        useMaterial3: true,
      ),
      themeMode: ThemeMode.system,
      home: DemoPage(),
    );
  }
}

/// Controller that handles the business logic of the demo page.
/// It uses GetX for reactive state management.
class DemoController extends GetxController {
  /// Observable state that determines the UI to show.
  var state = PageState.loading.obs;

  /// Observable error message used when the state is in [PageState.error].
  var errorMessage = ''.obs;

  /// Simulates data loading. Randomly succeeds or fails after a delay.
  void loadData() async {
    state.value = PageState.loading;

    // Simulate loading delay
    await Future.delayed(Duration(seconds: 2));

    // Randomly set state to success or error
    if (DateTime.now().second % 2 == 0) {
      state.value = PageState.success;
    } else {
      state.value = PageState.error;
      errorMessage.value = "Failed to load data";
    }
  }
}

/// A simple demo page that demonstrates how to use [PageStateBuilder]
/// with GetX reactive state management.
///
/// [PageStateBuilder] is a widget that conditionally builds UI based on a state.
/// - When `state` is [PageState.loading], it shows a loading widget.
/// - When `state` is [PageState.error], it shows an error widget (with retry).
/// - When `state` is [PageState.success], it shows the content provided by `successBuilder`.
///
/// The loading and error widgets are customizable by passing custom builders
/// like `loadingBuilder` and `errorBuilder`.
class DemoPage extends StatelessWidget {
  /// Register the controller using Get.put to enable dependency injection.
  final controller = Get.put(DemoController());

  DemoPage({super.key});

  @override
  Widget build(BuildContext context) {
    /// The responsive page wrapper is optional, to view the widgets in adaptative screen sizes
    return ResponsivePageWrapper(
      child: Scaffold(
        appBar: AppBar(title: Text('Simple GetX Example')),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              // Reactive observer that rebuilds when state or errorMessage changes
              Obx(
                () => PageStateBuilder(
                  state: controller.state.value,
                  errorMessage: controller.errorMessage.value,
                  onRetry: controller.loadData,
                  successBuilder: (_) => Text(
                    'Success!',
                    style: TextStyle(fontSize: 24),
                  ),
                  // You can also optionally provide:
                  // loadingBuilder: (_) => CustomLoadingWidget(),
                  // errorBuilder: (msg, onRetry) => CustomErrorWidget(msg: msg, onRetry: onRetry),
                ),
              ),
              SizedBox(height: 20),
              ElevatedButton(
                onPressed: controller.loadData,
                child: Text('Reload'),
              ),
            ],
          ),
        ),
      ),
    );
  }
}