pagination_controller 0.1.1+1

The `pagination_controller` package provides an abstract and reusable pagination logic for Flutter applications. It supports different pagination methods such as offset-based and page-based pagination [...]

Pagination Controller

The pagination_controller package provides an abstract and reusable pagination logic for Flutter applications. It supports different pagination methods such as offset-based and page-based pagination. It also integrates with ScrollController for automatic loading of new data as users scroll.

Features

• Supports different pagination methods: OffsetPagination, PagePagination.
• Mixin-based Pagination Handling: Allows easy integration with both Cubit and Flutter state management approaches.
• Error and Empty States Handling: Easily manage different states like errors, empty lists, and data retrieval success.
• Customizable: Allows usage of different item types, pagination strategies, and error types.

Installation

Add the following line to your pubspec.yaml file:

dependencies:
  pagination_controller: ^0.0.1

Then, run flutter pub get to install the package.

Usage

Example: Using Cubit for Pagination

import 'package:flutter/material.dart';
import 'package:pagination_controller/pagination_controller.dart';

class TemplateData {
  final int index;

  const TemplateData(this.index);
}

List<TemplateData> _testDataList =
    List<TemplateData>.generate(30, (index) => TemplateData(index));

void main() {
  runApp(const MainApp());
}

class MainApp extends StatefulWidget {
  const MainApp({super.key});

  @override
  State<MainApp> createState() => _MainAppState();
}

class _MainAppState extends State<MainApp> {
  final controller =
      CubitPaginationController<TemplateData, OffsetPagination, String>(
    firstPagePointer: const OffsetPagination(offset: 0),
    getPageFunc: (pagination) {
      return Future.delayed(
          const Duration(seconds: 2),
          () => SuccessPaginationResult(
                itemList: _testDataList
                    .skip(pagination.offset)
                    .take(pagination.limit)
                    .toList(),
                pagination: pagination,
              ));
    },
  );

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: const Text('Pagination Example')),
        body: SafeArea(
          child: RefreshIndicator(
            onRefresh: () async => controller.getFirst(),
            child: SingleChildScrollView(
              controller: controller.scrollController,
              child: CubitPaginatedListBuilder<TemplateData, OffsetPagination, String>(
                controller: controller,
                dataBuilder: (context, state, isProcessing) => Column(
                  crossAxisAlignment: CrossAxisAlignment.center,
                  children: [
                    ...state.itemList.map(
                      (e) => Container(
                        alignment: Alignment.center,
                        padding: const EdgeInsets.symmetric(vertical: 40),
                        child: Text(e.index.toString()),
                      ),
                    ),
                    if (isProcessing) const CircularProgressIndicator(),
                  ],
                ),
                emptyBuilder: (context, emptyState, isProcessing) => Container(
                  alignment: Alignment.center,
                  padding: const EdgeInsets.symmetric(vertical: 40),
                  child: const Text('No items available'),
                ),
                errorBuilder: (context, errorState, isProcessing) => Container(
                  alignment: Alignment.center,
                  padding: const EdgeInsets.symmetric(vertical: 40),
                  child: const Text('An error occurred'),
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}

Example: Using ScrollController for Pagination

final flutterController = FlutterPaginationController<ItemType, PagePagination, ErrorType>(
  firstPagePointer: PagePagination(page: 1),
  getPageFunc: (pagination) async {
    // Fetch data from an API or database
  },
);

// Use flutterController with any scrollable widget, like ListView

Pagination Methods

OffsetPagination

Offset-based pagination using a limit and offset strategy.

PagePagination

Page-based pagination using page numbers and limit per page.

State Management

The package supports three primary states:

1. DataListPCState: Holds the list of items and the current pagination state.
2. EmptyListPCState: Represents an empty list.
3. ErrorListPCState: Represents an error during pagination.

License

This package is licensed under the MIT License.