How to create PDF conformance document in Syncfusion Flutter PDF Library?

The Flutter PDF is a Flutter library used to create, read, and edit PDF documents. Using this library, you can create PDF conformance documents such as:

• PDF/A-1b conformance
• PDF/A-2b conformance
• PDF/A-3b conformance: The PDF/A-3b conformance supports the external files as an attachment to the PDF document, so you can attach any document formats such as Excel, Word, HTML, CAD, or XML files.

Steps to create a PDF conformance document programmatically

1. Create a new Flutter application project.

1.1.Open Visual Studio Code (After installing the Dart and Flutter extensions as stated in the setup editor page)

1.2.Click View -> Command Palette…

1.3.Type Flutter and choose Flutter: New Project.

1.4.Enter the project name and press the Enter button.

1.5.Now, choose the location of the project.

2. Add the following code in your pubspec.yaml file to install the syncfusion® flutter pdf package in your application. It will be automatically downloaded from the pub once you trigger the flutter pub to get a comment or the Get packages option from the Visual Studio Code.

   dependencies:
     syncfusion_flutter_pdf: ^20.3.49
   

3. Import the following package in your main.dart file.

   import 'package:syncfusion_flutter_pdf/pdf.dart';
   

4. Add the following code in the lib/main.dart file to create a simple button.

   @override
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
         title: Text(widget.title),
       ),
       body: Center(
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
           children: <Widget>[
             TextButton(
               child: Text(
                 'Generate PDF',
                 style: TextStyle(color: Colors.white),
               ),
               style: ButtonStyle(
                   backgroundColor: MaterialStateProperty.resolveWith(
                       (states) => Colors.blue)),
               onPressed: createConformancePdf,
             )
           ],
         ),
       ),
     );
   }
   

5. Add the following code to the createConformancePdf method to create a PDF conformance document programmatically.

   Future<void> createConformancePdf() async {
     //Create a new PDF document with conformance A1B.
     PdfDocument document =
         PdfDocument(conformanceLevel: PdfConformanceLevel.a1b)
           ..pages.add().graphics.drawString('Hello World!',
               PdfTrueTypeFont(await _readData('Roboto-Regular.ttf'), 12),
               brush: PdfBrushes.red, bounds: Rect.fromLTWH(0, 0, 200, 15));
     //Save and dispose the document.
     final List<int> bytes = await document.save();
     document.dispose();
     //Save the file and launch/download.
     SaveFile.saveAndLaunchFile(bytes, 'output.pdf');
   }
   

6. Include the following code to read the font file from the folder where it is saved. Here, we have named our folder as assets.

   Future<List<int>> _readData(String name) async {
     final ByteData data = await rootBundle.load('assets/$name');
     return data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
   }
   

7. Before that, mention the asset to pubspec.yaml file as follows.

# To add assets to your application, add an assets section, like this:
assets:
  - assets/Roboto-Regular.ttf

8. Use the following code to save and launch the generated PDF file.

       Web:

8.1.Add the web package as a dependency in your pubspec.yaml file. Then, create a new Dart file named save_file_web.dart. Finally, add the following code to implement the file download functionality using the web package.

import 'dart:convert';
import 'package:web/web.dart' as web;

8.2.To enable file saving and initiate downloads in a Flutter web environment, use the following code within the saveAndLaunchFile method

// Function to save and launch a file for download in a web environment
Future<void> saveAndLaunchFile(List<int> bytes, String fileName) async {
  final web.HTMLAnchorElement anchor =
      web.document.createElement('a') as web.HTMLAnchorElement
        ..href = "data:application/octet-stream;base64,${base64Encode(bytes)}"
        ..style.display = 'none'
        ..download = fileName;

// Insert the new element into the DOM
web.document.body!.appendChild(anchor);

// Initiate the download
anchor.click();
// Clean up the DOM by removing the anchor element
web.document.body!.removeChild(anchor);
}

       Desktop and Mobile:

8.3.Add the following dependencies in your pubspec.yaml file.

open_file: ^3.2.1   #Open source library to launch the PDF file in mobile devices
path_provider: ^2.0.11

8.4.Create a new dart file named save_file_mobile_and_desktop.dart under the lib folder and  import the following packages in save_file_mobile_and_desktop.dart file.

import 'dart:io';
import 'package:open_file/open_file.dart';
import 'package:path_provider/path_provider.dart';

8.5.Include the following code snippet in save_file_mobile_and_desktop.dart to open the PDF document in Desktop and Mobile.

class SaveFile {
   static Future<void> saveAndLaunchFile(
      List<int> bytes, String fileName) async {
    //Get external storage directory
    Directory directory = await getApplicationSupportDirectory();
    //Get directory path
    String path = directory.path;
    //Create an empty file to write PDF data
    File file = File('$path/$fileName');
    //Write PDF data
    await file.writeAsBytes(bytes, flush: true);
    //Open the PDF document in mobile
    OpenFile.open('$path/$fileName');
  }
}

9. Run the sample using the flutter run command. This will create a PDF conformance document. After the application launches, you will get the PDF document as follows.

A complete working sample can be downloaded from conformance.zip

Take a moment to peruse the documentation. You can find other options like PDF/A-1b conformance, PDF/A-2b conformance, PDF/A-3b conformance in the PDF document, and features like adding layers, interactive annotations, and insert a hyperlink to PDF with code examples.