Flutter Pagination Wrapper

A widget that wraps a ListView or any type of ScrollView, and provides pagination functionality.

Instalation

Add to your pubspec:

dependencies:
  flutter_paginator: ^0.1.2

Import:

import 'package:flutter_pagination_wrapper/flutter_pagination_wrapper.dart';

Usage

Now, you can use a Paginator widget.

The Paginator takes many different methods used to supply it with data and to provide builders to build the list items.

It also takes a PaginatorChildBuilder, which should use the given itemBuilder method and temCount integer to create and return a ScrollView. The itemBuilder method and itemCount integer can be directly passed into a ListView.builder or GridView.builder's respective arguments.

The various method arguments are documented in the constructor documentation (and in this README), and allow a lot of flexibility.

Here, the listBuilder returns a ListView.builder as an example - but it can be anything, as long as it uses the passed arguments properly. The one rule is that the itemBuilder should not be called unless the item is going to be displayed on-screen.

Paginator<ItemType, ItemType>(
  key: _paginationKey,
  pageLoadFuture: pageLoadFuture,
  pageErrorChecker: pageErrorChecker,
  totalItemsGetter: totalItemsGetter,
  pageItemsGetter: pageItemsGetter,
  itemListTileBuilder: itemListTileBuilder,
  loadingListTileBuilder: loadingListTileBuilder,
  errorListTileBuilder: errorListTileBuilder,
  emptyListWidgetBuilder: emptyListWidgetBuilder,
  listBuilder: (context, itemBuilder, itemCount) {
    return ListView.builder(
      itemBuilder: itemBuilder,
      itemCount: itemCount,
    );
  },
 );

Method types for the constructor

This section describes the types of methods that this widget's constructor takes.

PageLoadFuture

Returns a new page (of type PageType). This should contain the data to display in that page, as well as any other info to be used by other callbacks.

PageErrorChecker

Checks the passed page for errors.
Returns true if there are any errors.

TotalItemsGetter

Returns an int with the value of the total number of items that will ever be displayed.
The widget will not attempt to load any more data once this count has been reached.
This number can be updated after each new page is loaded.

PageItemsGetter

This method should receive the page object from the PageLoadFuture (of type PageType), and return a list of type ItemType.

ItemListTileBuilder

This method should take an item from the list returned from the PageItemsGetter, and return a Widget to be rendered in the list.

LoadingListTileBuilder

This method should return a Widget to be displayed at the bottom of the list, as the next page loads.

ErrorListTileBuilder

This method should return a Widget to be displayed at the bottom of the list if there's an error fetching the new page (that is, if the PageErrorChecker returns true).

EmptyListWidgetBuilder

This method should return a Widget that displays when there are no items.

Attribution

This package takes heavy inspiration from UdaraWanasinghe's flutter_paginator package, and the widget constructor is quite similar - migration should be fairly straightforward.

The difference between that package and mine is that while that package builds the ListView or equivalent for you, mine uses a passed-in builder, allowing for more flexibility.

License

Copyright 2020 hacker1024

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

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