How can i show pdf in base64 format in flutter - flutter

Question

I have a table in postgresql that has a field with a pdf file in base64 format. When I get it from flutter, how can I show it with pdf viewer ?, has anyone done it ??
I appreciate your help

Answer 1

In pubspec.yaml add the following dependency:
dependencies:
flutter_full_pdf_viewer: ^1.0.6 # for pdf
Then run flutter pub get in Android Studio terminal to update dependencies.
Create the file 'pdfBase64Viewer.dart:
import 'dart:async'; // asynchroneous function (await)
import 'dart:io'; // write the file on user's phone
import 'dart:convert'; // handle base64 decoding
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_full_pdf_viewer/full_pdf_viewer_scaffold.dart';
import 'package:path_provider/path_provider.dart';
class PdfBase64Viewer extends StatefulWidget {
final String url;
const PdfBase64Viewer(String this.url);
#override
_PdfBase64ViewerState createState() => new _PdfBase64ViewerState();
}
class _PdfBase64ViewerState extends State<PdfBase64Viewer> {
String pathPDF = "";
#override
void initState() {
super.initState();
createFileOfPdfUrl(widget.url).then((f) {
setState(() {
pathPDF = f.path;
print(pathPDF);
});
});
}
Future<File> createFileOfPdfUrl(is_base_64) async {
final filename = widget.url.substring(widget.url.lastIndexOf("/") + 1);
var request = await HttpClient().getUrl(Uri.parse(widget.url));
var response = await request.close();
var bytes = await consolidateHttpClientResponseBytes(response);
var base64String = utf8.decode(bytes);
var decodedBytes = base64Decode(base64String.replaceAll('\n', ''));
String dir = (await getApplicationDocumentsDirectory()).path;
File file = new File('$dir/$filename');
await file.writeAsBytes(decodedBytes.buffer.asUint8List());
return file;
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: const Text('Plugin example app')),
body: Center(
child: RaisedButton(
child: Text("Open PDF"),
onPressed: () => Navigator.push(
context,
MaterialPageRoute(builder: (context) => PDFScreen(pathPDF)),
),
),
),
);
}
}
class PDFScreen extends StatelessWidget {
String pathPDF = "";
PDFScreen(this.pathPDF);
#override
Widget build(BuildContext context) {
return PDFViewerScaffold(
appBar: AppBar(
title: Text("Document"),
actions: <Widget>[
IconButton(
icon: Icon(Icons.share),
onPressed: () {},
),
],
),
path: pathPDF);
}
}
You can adapt above class in order to assign to the variable base64String the String value that you get from your DB.
You can use it the following way:
import 'pdfBase64Viewer.dart';
(...)
child: PdfBase64Viewer("https://filebin.net/qmvmxbgn6pzgkbzb/sample.base64?t=7g5s9rwr") // url of your base64 file
(...)
You might want to check the following documentation:
Base64
Full Pdf Viewer