# Flutter Paginator [![pub package](https://img.shields.io/badge/pub-v0.0.6-orange)](https://pub.dev/packages/flutter_paginator) A customizable pagination package for Flutter. This package can be used to fetch and display data from an API page by page. ## Screenshots

## Installing ``` dependencies: flutter_paginator: ^0.0.6 ``` ## Description `Paginator` extends `StatefulWidget` has 3 constructors namely `Paginator.listView`, `Paginator.gridView` and `Paginator.pageView`. `Paginator.listView`, `Paginator.gridView` and `Paginator.pageView` are descendants of `ListView`, `GridView` and `PageView`. `Paginator.listView`, `Paginator.gridView` and `Paginator.pageView` got all the features of their ancestors and they are need to provide additional functions that are essential in doing their task. ### `PageLoadFuture` * Loads the page asynchronously when the page number is given. * This should return an instance of a `Future`. * Called when the next page is needed to be loaded. ### `PageItemsGetter` * This function should return list of page item data when page data is given. * This is called after successful completion of `PageLoadFuture`. * The page items returned by this method is added to the list of all the page items. ### `ListItemBuilder` * Builds list item when item data and item index are given. * This should return an instance of a `Widget`. ### `LoadingWidgetBuilder` * Builds loading widget. * This should return an instance of a `Widget`. ### `ErrorWidgetBuilder` * Builds error widget when page data and error callback are given. * This should return an instance of a `Widget`. ### `EmptyListWidgetBuilder` * Builds empty list widget. * This is displayed when the total number of list items is zero. * This should return an instance of a `Widget`. ### `TotalItemsGetter` * This should return total number of list items when page data is given. ### `PageErrorChecker` * This should return true if page has error else false, when page data is given. ## Using ```dart import 'dart:async'; import 'dart:convert'; import 'dart:io'; import 'package:flutter/material.dart'; import 'package:http/http.dart' as http; import 'package:flutter_paginator/flutter_paginator.dart'; import 'package:flutter_paginator/enums.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return MaterialApp( title: 'Flutter Paginator', home: HomePage(), ); } } class HomePage extends StatefulWidget { @override State createState() { return HomeState(); } } class HomeState extends State { GlobalKey paginatorGlobalKey = GlobalKey(); @override Widget build(BuildContext context) { return Scaffold( appBar: AppBar( title: Text('Flutter Paginator'), actions: [ IconButton( icon: Icon(Icons.format_list_bulleted), onPressed: () { paginatorGlobalKey.currentState .changeState(listType: ListType.LIST_VIEW); }, ), IconButton( icon: Icon(Icons.grid_on), onPressed: () { paginatorGlobalKey.currentState.changeState( listType: ListType.GRID_VIEW, gridDelegate: SliverGridDelegateWithFixedCrossAxisCount( crossAxisCount: 2), ); }, ), IconButton( icon: Icon(Icons.library_books), onPressed: () { paginatorGlobalKey.currentState .changeState(listType: ListType.PAGE_VIEW); }, ), ], ), body: Paginator.listView( key: paginatorGlobalKey, pageLoadFuture: sendCountriesDataRequest, pageItemsGetter: listItemsGetter, listItemBuilder: listItemBuilder, loadingWidgetBuilder: loadingWidgetMaker, errorWidgetBuilder: errorWidgetMaker, emptyListWidgetBuilder: emptyListWidgetMaker, totalItemsGetter: totalPagesGetter, pageErrorChecker: pageErrorChecker, scrollPhysics: BouncingScrollPhysics(), ), floatingActionButton: FloatingActionButton( onPressed: () { paginatorGlobalKey.currentState.changeState( pageLoadFuture: sendCountriesDataRequest, resetState: true); }, child: Icon(Icons.refresh), ), ); } Future sendCountriesDataRequest(int page) async { try { String url = Uri.encodeFull( 'http://api.worldbank.org/v2/country?page=$page&format=json'); http.Response response = await http.get(url); return CountriesData.fromResponse(response); } catch (e) { if (e is IOException) { return CountriesData.withError( 'Please check your internet connection.'); } else { print(e.toString()); return CountriesData.withError('Something went wrong.'); } } } List listItemsGetter(CountriesData countriesData) { List list = []; countriesData.countries.forEach((value) { list.add(value['name']); }); return list; } Widget listItemBuilder(value, int index) { return ListTile( leading: Text(index.toString()), title: Text(value), ); } Widget loadingWidgetMaker() { return Container( alignment: Alignment.center, height: 160.0, child: CircularProgressIndicator(), ); } Widget errorWidgetMaker(CountriesData countriesData, retryListener) { return Column( mainAxisAlignment: MainAxisAlignment.center, children: [ Padding( padding: const EdgeInsets.all(16.0), child: Text(countriesData.errorMessage), ), FlatButton( onPressed: retryListener, child: Text('Retry'), ) ], ); } Widget emptyListWidgetMaker(CountriesData countriesData) { return Center( child: Text('No countries in the list'), ); } int totalPagesGetter(CountriesData countriesData) { return countriesData.total; } bool pageErrorChecker(CountriesData countriesData) { return countriesData.statusCode != 200; } } class CountriesData { List countries; int statusCode; String errorMessage; int total; int nItems; CountriesData.fromResponse(http.Response response) { this.statusCode = response.statusCode; List jsonData = json.decode(response.body); countries = jsonData[1]; total = jsonData[0]['total']; nItems = countries.length; } CountriesData.withError(String errorMessage) { this.errorMessage = errorMessage; } } ```

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