The getter 'size' isn't defined for the type 'TaskData'

Question

This is one of the cases that makes it is difficult to learn flutter. Here is an example directly from (code source):

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'package:task_management/model/task_data.dart';

class TaskList extends StatelessWidget {
@override
Widget build(BuildContext context) {
    return Consumer<TaskData>(builder: (context, data, child) {
    return ListView.builder(
        scrollDirection: Axis.vertical,
        shrinkWrap: true,
        itemCount: data.size,
        itemBuilder: (context, index) {
        final task = data.tasks[index];
            
        // gesture detection
        return GestureDetector(
            onLongPress: () => data.removeTask(task),
            child: Container(
            margin: EdgeInsets.only(bottom: 10),
            padding: EdgeInsets.fromLTRB(12, 5, 8, 5),
            width: double.infinity,
            decoration: BoxDecoration(
                color: Colors.black12,
                borderRadius: BorderRadius.circular(8)),
            child: Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                    
                // text field
                Text(
                    task.task,
                    style: TextStyle(
                        decoration:
                            task.completed ? TextDecoration.lineThrough : null,
                        fontSize: 16,
                        fontWeight: FontWeight.bold),
                ),
                    
                // switch case
                Switch(
                    value: task.completed,
                    onChanged: (c) => data.toggleTask(task),
                ),
                ],
            ),
            ),
        );
        },
    );
    });
}
}

But it brings up the inevitable error message: "The getter 'length' isn't defined for the type 'TaskData.'" Any easy way to fix this?

Answer 1

From the looks of it, it actually needs to be

    itemCount: data.tasks.length,