Flutter CSV: A Comprehensive Guide

by

In the realm of Flutter development, working with CSV (Comma-Separated Values) data is a common task. CSV files are a versatile format for storing and exchanging structured data, making them widely used in various applications. This guide will provide a comprehensive overview of CSV handling in Flutter using Flutter CSV, covering essential concepts, best practices, and practical examples.

We’ll delve into the process of reading, writing, and manipulating CSV data using popular Flutter packages. You’ll learn how to parse CSV files, extract specific data, and format output in desired formats. Additionally, we’ll discuss techniques for handling large CSV files efficiently and addressing potential challenges that may arise during CSV processing.

By the end of this guide, you’ll have a solid understanding of CSV operations in Flutter and be equipped to effectively work with CSV data in your projects.

What is Flutter CSV Field Matching?

Flutter CSV field matching enables you to seamlessly connect the data in your CSV files with the information displayed in your app. This is essential for tasks like displaying, downloading, or processing CSV data within your Flutter application.

To effectively work with CSV files in Flutter, the official Flutter CSV package is your go-to solution. This package provides a comprehensive set of tools for handling CSV data, allowing you to easily access and manipulate its contents.

Let’s explore some common scenarios where Flutter CSV field matching proves invaluable:

  • Data Import and Export: Easily import CSV data into your app for further processing or export app data to CSV format for analysis or sharing.
  • Reporting and Analytics: Generate detailed reports or perform data analysis by extracting relevant information from CSV files.
  • Integration with External Systems: Connect your Flutter app with other systems that use CSV data for data exchange.
  • Data Validation: Ensure data integrity by verifying the consistency and accuracy of CSV data against your app’s requirements.
  • Custom Data Processing: Tailor CSV data processing to your specific needs, such as filtering, sorting, or transforming data.

Flutter CSV Dart package

With the help of this plugin, you will be able to perform flutter CSV field matching. It has multiple functions that help you in CSV data processing in Flutter.

1.   Dart CSV to List Converter

Your values must be in a List<List<dynamic>> form to be converted to a CSV string by the algorithm.

String csv = const ListTocsvConverter().convert(yourListOfLists);

2.  The Decoder

Every CSV row is converted to a list of values by the use of a decoder. The strings looking like numbers (integers and doubles) and unquoted are, by default, converted to ints or doubles.

3.  The Encoder

In the encoder, the input must be a List of Lists. Each information of the inner list is converted to one output CSV row. After encoding, you get the string representation of values by calling toString.

Hence, this plugin is your acquaintance while using a CSV file for a Flutter app. It helps you in Flutter CSV field matching and processing the data.

Reading Data From CSV in Flutter

Following is a step-by-step process in Flutter CSV field matching that enables you to read data from CSV.

  •   First, create the Flutter application.
  •   Now include your required libraries into pubspec.yaml file.
  •   Import CSV File and read the data from the CSV file
  •   Display the CSV data flutter on Listview.
  •   Finally, run the application.

Displaying a CSV file in Flutter UI

CSV stands for Comma-Separated Values. It’s a file type widely used to store tabular data (numbers and text) in plain text. Each line will have the same number of fields in CSV.

To work with CSV in Flutter, you must install a CSV package in Flutter. To install this package, open a terminal inside your project folder, and run it. After that CSV package will install in your project. You can confirm this by looking at pubspec.

Opening a File in Flutter

Add the packages and run the below command in the terminal to add the file picker flutter.

Flutter pub adds file_picker. To add the open_file package, run this command: flutter pub add open_file. 

To import the CSV file into Flutter app, use file_picker and open_file packages to import them and then add the below line in your lib/main.

Importing CSV Files in Flutter

You can use the Flutter CSV library to import files of your choice. Flutter CSV field matching can be done in this case by using the following command and code. You will successfully import your CSV files into Flutter.

pickFile() async {
   FilePickerResult result = await FilePicker.platform.pickFiles();
   if (result != null) {
 	PlatformFile file = result.files.first;
 
 	final input = new File(file.path).openRead();
 	final fields = await input
         .transform(utf8.decoder)
         .transform(new csvToListConverter())
     	.toList();
 
 	print(fields);
   }
 }

Saving a CSV file in Flutter

First, you need to create a file on the specified path to store all the CSV data inside a file. Then write CSV data using writeAsString method. To view CSV data after saving a CSV file to your phone’s storage, go to LoadcsvDataScreen.

Reading an Excel file in Flutter

You will successfully read an excel file in Flutter using the below method.

  •   First, create an excel document.
  •   Now add text, date, and time, and add formulas.
  •   Then apply formatting, images, charts, and hyperlinks
  •   At last, protect the workbook or worksheet.

Convert List of String to CSV

data is a List of strings. We change this list to a CSV file using ListToCSVConverter () which uses the convert() method to convert data to CSV data. Get the directory path for the application and make a new custom path to put all of our CSV files in.

final String directory = (await getApplicationSupportDirectory()).path;
final path = "$directory/csv-${DateTime.now()}.csv";";

We must create a file in the designated directory to save all of the CSV data inside of it. Then use the writeAsString function to write CSV data.

generatecsv() async {
 List<List<String>> data = [
   ["No.", "Name", "Roll No."],
   ["1", randomAlpha(3), randomNumeric(3)],
   ["2", randomAlpha(3), randomNumeric(3)],
   ["3", randomAlpha(3), randomNumeric(3)]
 ];
 String csvData = ListTocsvConverter().convert(data);
 final String directory = (await getApplicationSupportDirectory()).path;
 final path = "$directory/csv-${DateTime.now()}.csv";
 print(path);
 final File file = File(path);
 await file.writeAsString(csvData);
 Navigator.of(context).push(
   MaterialPageRoute(
 	builder: (_) {
   	return LoadcsvDataScreen(path: path);
 	},
   ),
 );
}

To view CSV data after saving a CSV file to your phone’s storage, go to LoadcsvDataScreen

Fetching CSV files from the phone storage

In this Flutter CSV field matching type, you fetch all the CSV files needed to get the directory path. To act you can use this code. 

final String directory = (await getApplicationSupportDirectory()).path;
final path = "$directory/";
After getting into the directory we need to sync all the entities with a list of FileSystemEntity 
Future<List<FileSystemEntity>> _getAllcsvFiles() async {
 final String directory = (await getApplicationSupportDirectory()).path;
 final path = "$directory/";
 final myDir = Directory(path);
 List<FileSystemEntity> _csvFiles;
 _csvFiles = myDir.listSync(recursive: true, followLinks: false);
 _csvFiles.sort((a, b) {
   return b.path.compareTo(a.path);
 });
 return _csvFiles;
}

]

Conclusion

CSV files are a valuable format for storing and exchanging data in Flutter applications. By mastering the techniques outlined in this guide, you’ll be able to efficiently read, write, and manipulate CSV data, enhancing the capabilities of your Flutter projects.

Remember to choose the appropriate Flutter package based on your specific requirements and leverage best practices for handling large CSV files and addressing potential challenges. With a strong grasp of CSV operations in Flutter, you’ll be well-equipped to build robust and scalable applications that effectively work with structured data.

Leave a comment