Convert List<List<dynamic>> to ArrayList in Flutter

Question

I'm new to flutter and i want to convert a List<List> to ArrayList. here's my current list output

data [[Qty, Desc, Unitprice, totalprice], [1, Jeans, 106.0, 106.0], [2, Shirt, 24.38, 24.38], [3, Demo Hoodie / XL, 106.0, 318.0], [4, Demo Hoodie / 2XL, 106.0, 106.0], [1, Jeans-short, 106.0, 106.0], [5, Shirt-Long, 24.38, 24.38], [6, Demo Hoodie-Lg / XL, 106.0, 318.0], [4, Demo Hoodie-Mg / 2XL, 106.0, 106.0], [3, Jeans-RG, 106.0, 106.0], [4, Shirt-MG, 24.38, 24.38], [7, Demo Hoodie-TY / XL, 106.0, 318.0], [9, Demo Hoodie-Levis / 2XL, 106.0, 106.0], [1, Demo Hoodie-J&J / XL, 106.0, 318.0], [2, Demo Hoodie-M&J / 2XL, 106.0, 106.0], [7, Temo Hoodie-TY / XL, 106.0, 318.0], [5, Zemo Hoodie-Levis / 2XL, 106.0, 106.0], [6, Aemo Hoodie-J&J / XL, 106.0, 318.0], [2, Bemo Hoodie-M&J / 2XL, 106.0, 106.0], [9, Temo Hoodie-TY / XL, 106.0, 318.0], [1, Zemo Hoodie-Levis / 2XL, 106.0, 106.0], [2, Aemo Hoodie-J&J / XL, 106.0, 318.0], [7, Bemo Hoodie-M&J / 2XL, 106.0, 106.0]]

I want to add that array list into recyclerView in flutter.

Thanks in advance.

Answer 1

You can either use dart:convert and use jsonDecode but that won't work unless you remove strings from this for add single/double quotes to each word.

Or you could convert it manually by splitting the string.

import 'dart:core';

main(){
  
 String data = "[[Qty, Desc, Unitprice, totalprice], [1, Jeans, 106.0, 106.0], [2, Shirt, 24.38, 24.38], [3, Demo Hoodie / XL, 106.0, 318.0], [4, Demo Hoodie / 2XL, 106.0, 106.0], [1, Jeans-short, 106.0, 106.0], [5, Shirt-Long, 24.38, 24.38], [6, Demo Hoodie-Lg / XL, 106.0, 318.0], [4, Demo Hoodie-Mg / 2XL, 106.0, 106.0], [3, Jeans-RG, 106.0, 106.0], [4, Shirt-MG, 24.38, 24.38], [7, Demo Hoodie-TY / XL, 106.0, 318.0], [9, Demo Hoodie-Levis / 2XL, 106.0, 106.0], [1, Demo Hoodie-J&J / XL, 106.0, 318.0], [2, Demo Hoodie-M&J / 2XL, 106.0, 106.0], [7, Temo Hoodie-TY / XL, 106.0, 318.0], [5, Zemo Hoodie-Levis / 2XL, 106.0, 106.0], [6, Aemo Hoodie-J&J / XL, 106.0, 318.0], [2, Bemo Hoodie-M&J / 2XL, 106.0, 106.0], [9, Temo Hoodie-TY / XL, 106.0, 318.0], [1, Zemo Hoodie-Levis / 2XL, 106.0, 106.0], [2, Aemo Hoodie-J&J / XL, 106.0, 318.0], [7, Bemo Hoodie-M&J / 2XL, 106.0, 106.0]]";
  
  
  List<String> splittedData = data.substring(2,data.length-1).split("], [");


  List<List<String>> formattedData = [];

  splittedData.forEach( (stringVal) => formattedData.add(stringVal.split(', ')));

  print(formattedData[0][0]);
  

}

You run this code dartpad.dev to check its output.

You improve this further by using regular expressions to parse the data instead of splitting it using a string. That would be the case where the data itself isn't consistent and has single quotes/double quotes and square brackets in it.

Answer 2

• You should use objects for this kind of usage like List<Product> stead of List<List>

• There is no RecyclerView in Flutter, it's ListView widget.

• Your strings should be between quotes ("")

Here is an example with ListView builder:

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  
  var list = [["data1", "data2"], ["data1","data2"],["data1","data2"]];

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: ListView.builder(
          itemCount: list.length,
          itemBuilder: (context, index) {
            return Container(
              color: Colors.grey[200],
              padding: EdgeInsets.symmetric(vertical: 10),
              child: Row(
                mainAxisAlignment: MainAxisAlignment.center,
                children: List.generate(
                  list[index].length,
                  (index2) {
                    return Text(list[index][index2]);
                  }
                )
              ),
            );
          }
        )
      ),
    );
  }
}