多级排序

multi_sort

A fast and powerful Flutter package helps you sort a list of objects by one or more properties at the same time.

Why?

Suppose you have a list of Phones and you want to sort it according to there specification like RAM, Storage, Price, Camera, etc. at the same time similar to Microsoft Excel sorting.

Suppose I have a list of phones as following.

List<Phone> items = [
    Phone("real me 6", 6, 18999, 128),
    Phone("real me 6", 8, 19999, 128),
    Phone("real Note 8", 7, 16999, 128),
    Phone("oppo a9", 4, 13999, 128),
    Phone("real me 6 pro", 6, 17999, 64),
    Phone("Oppo 5as", 2, 8999, 32),
    Phone("Real me 5i", 4, 10999, 64),
    Phone("Poco x2", 6, 18500, 128),
  ]

After sorting in the preference order of first by RAM and then by Storage you will get

[
    Phone("real me 6", 8, 19999, 128),
    Phone("real Note 8", 7, 16999, 128),
    Phone("real me 6", 6, 18999, 128),
    Phone("Poco x2", 6, 18500, 128),
    Phone("real me 6 pro", 6, 17999, 64),
    Phone("oppo a9", 4, 13999, 128),
    Phone("Oppo 5as", 2, 8999, 32),
    Phone("Real me 5i", 4, 10999, 64),
 ]

Using this Flutter Package, you can do this Preference Sort/Multiple Sorts/ Multiple level Sorts at the same time very easily.

Installing

1. Depend on it

Add this to your package's pubspec.yaml file:

dependencies:
  multi_sort: ^3.0.0

2. Install it

You can install packages from the command line:

with Flutter:

$ flutter pub get

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:

import 'package:multi_sort/multi_sort.dart';

Documentation

• dynamic preferrence List of properties in which you want to sort the list i.e. List<property> preferrence = ['property1','property2'] first sort the list by property1 then by property2.
• List<bool> criteria List of booleans that specifies the criteria of sort i.e., For ascending order true and for descending order false.

Usage

Initialization

List<property> list; // List of Items
List<bool> criteria ; //Criteria List
List<String> preferrence ; //prefrrence List

Now sort the list using multisort

list.multisort(criteria, preferrence);

Example

import 'package:flutter/material.dart';
import "package:multi_sort/multi_sort.dart";

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: ExampleApp(),
    );
  }
}

class ExampleApp extends StatefulWidget {
  ExampleApp({Key key}) : super(key: key);

  @override
  _ExampleAppState createState() => _ExampleAppState();
}

/// Class of Items
class Items {
  String name;
  int ram;
  int price;
  int storage;
  Items(this.name, this.ram, this.price, this.storage);

  ///Mapping the properties
  Map<String, dynamic> _toMap() {
    return {'name': name, 'price': price, 'ram': ram, 'storage': storage};
  }

  ///get function to get the properties of Item
  dynamic get(String propertyName) {
    var _mapRep = _toMap();
    if (_mapRep.containsKey(propertyName)) {
      return _mapRep[propertyName];
    }
    throw ArgumentError('propery not found');
  }
}

class _ExampleAppState extends State<ExampleApp> {
  //List of Items
  List<Items> items = [
    Items("real me 6", 6, 18999, 128),
    Items("real me 6", 8, 19999, 128),
    Items("real Note 8", 7, 16999, 128),
    Items("oppo a9", 4, 13999, 128),
    Items("real me 6 pro", 6, 17999, 64),
    Items("Oppo 5as", 2, 8999, 32),
    Items("Real me 5i", 4, 10999, 64),
    Items("Poco x2", 6, 18500, 128),
  ];
  // Temp List for sorting
  List<Items> sortingList = [];
  //Criteria List
  List<bool> criteria = [false, false];
  //prefrrence List
  List<String> preferrence = ['ram', 'storage'];

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    setState(() {
      sortingList = items;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Sort List Example"),
      ),
      body: Column(
        children: [
          _buttons(),
          ListView.builder(
              shrinkWrap: true,
              itemCount: sortingList.length,
              itemBuilder: (BuildContext context, int i) {
                return Card(
                  child: Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      Text(sortingList[i].name),
                      Text(sortingList[i].price.toString()),
                      Text(sortingList[i].ram.toString()),
                      Text(sortingList[i].storage.toString()),
                    ],
                  ),
                );
              }),
        ],
      ),
    );
  }

  Widget _buttons() {
    return RaisedButton(
      onPressed: () {
        setState(() {
          ///Sorting using MultiSort
          sortingList.multisort(criteria, preferrence);
        });
      },
      child: Text('Sort by preferrence'),
    );
  }
}

License

multi_sort is licensed under MIT license.

MIT License

Copyright (c) 2020 Deependra Chansoliya

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.