Cookbooks
Dart
Chapter 10. Data Formats and Serialization
Working with CSV

Dart:
Working with CSV

How to:

To handle CSV files in Dart, you typically either manually process the text or use third-party libraries to simplify the task. Here, we’ll look at both approaches.

Manually Parsing CSV

If your needs are simple, you might opt to manually parse a CSV string. This can be achieved using Dart’s core string manipulation functions:

void main() {
  // Sample CSV data
  String csvData = "Name,Age,Email\nJohn Doe,30,[email protected]\nJane Smith,25,[email protected]";
  
  // Splitting the CSV data into lines
  List<String> lines = csvData.split('\n');
  
  // Parsing each line
  List<Map<String, String>> data = [];
  List<String> headers = lines.first.split(',');
  
  for (var i = 1; i < lines.length; i++) {
    List<String> row = lines[i].split(',');
    Map<String, String> record = {};
    for (var j = 0; j < headers.length; j++) {
      record[headers[j]] = row[j];
    }
    data.add(record);
  }
  
  // Output the parsed data
  print(data);
}

// Sample output:
// [{Name: John Doe, Age: 30, Email: john@example.com}, {Name: Jane Smith, Age: 25, Email: jane@example.com}]

Using a Third-Party Library: csv

For more complex scenarios or to simplify your code, you can use a popular third-party library like csv. First, add it to your project by including csv: ^5.0.0 (or the latest version) in your pubspec.yaml file under dependencies. Then use it as follows:

import 'package:csv/csv.dart';

void main() {
  String csvData = "Name,Age,Email\nJohn Doe,30,[email protected]\nJane Smith,25,[email protected]";
  
  // Use the CsvToListConverter to parse the CSV data
  List<List<dynamic>> listData = const CsvToListConverter().convert(csvData);
  
  // The first list item contains headers
  List<String> headers = listData.first.map((item) => item.toString()).toList();
  
  // Removing the header row before processing further
  listData.removeAt(0);
  
  // Convert to List<Map<String, dynamic>> for a more structured format
  List<Map<String, dynamic>> mappedData = listData.map((list) {
    Map<String, dynamic> map = {};
    for (int i = 0; i < headers.length; i++) {
      map[headers[i]] = list[i];
    }
    return map;
  }).toList();
  
  // Output the mapped data
  print(mappedData);
}

// Sample output:
// [{Name: John Doe, Age: 30, Email: john@example.com}, {Name: Jane Smith, Age: 25, Email: jane@example.com}]

Both methods demonstrate how to work with CSV data: the first manually, for learning purposes or when dealing with very simple CSV structures; the second, by leveraging a powerful library that simplifies parsing and can handle various complexities of CSV formatting.

Working with JSON