Just switched from flutter_plugin_pdf_viewer to advance_pdf_viewer, and facing 3 issues

[Appvala]

Just switched from flutter_plugin_pdf_viewer to advance_pdf_viewer, and facing 3 issues while running the app. These are the 3 issues :

1. ../../Flutter/flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart:64:14: Error: The class 'File' is abstract and can't be instantiated.
   file = File("${dir.path}/file.pdf");

2. ../../Flutter/flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart:72:26: Error: Non-nullable variable 'file' must be assigned before it can be used.
   document._filePath = file.path;

3. ../../Flutter/flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart:75:58: Error: Non-nullable variable 'file' must be assigned before it can be used.
   .invokeMethod('getNumberOfPages', {'filePath': file.path});

I am using this code:

`
class _ChapterState extends State {
bool _isLoading = true;
PDFDocument document;

@OverRide
void initState() {
super.initState();
loadDocument();
}

loadDocument() async {
document = await PDFDocument.fromAsset(widget.category.chapter);
setState(() => _isLoading = false);
}

@OverRide
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Theme.of(context).scaffoldBackgroundColor,
appBar: AppBar(
centerTitle: false,
backgroundColor: Theme.of(context).accentColor,
title: Text(
widget.category.name,
),
),
body: Center(
child: _isLoading
? Center(
child: CircularProgressIndicator(),
)
: PDFViewer(document: document),
),
);
}
}
`
Kindly help.

[EugenEistrach]

Same for me, using latest flutter version 2.2.1

[gorkemg0]

I am having the same problem. I am using flutter version 2.2.1

[himalaya-08]

same for me

[quocviet1996]

same for me

[hkhars]

I am facing the same issue with flutter v2.2.1

[iamvikashh]

I think the problem is due to the import file in the plugin itself. I don't know for sure but the File class object we are passing is from 'dart:io' but in the plugin, the File which it is expecting is abstract class File.

[gorkemg0]

yes, I saw the problem with the file class too. I added 'as' while importing. My problem is not solved. there is still a problem.

[kushalmahapatro]

Came across this issue after upgrading to Flutter 2.2.1 and even the same persisted after downgrading it to 2.2.0.

Sol, that worked:

Edited the /flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart

import 'dart:io'; - > import 'dart:io' as io; : line 2

static Future fromAsset(String asset) async {
io.File file; // Edited
try {
var dir = await getApplicationDocumentsDirectory();
file = io.File("${dir.path}/file.pdf"); // Edited
var data = await rootBundle.load(asset);
var bytes = data.buffer.asUint8List();
await file.writeAsBytes(bytes, flush: true);
} catch (e) {
throw Exception('Error parsing asset file!');
}
PDFDocument document = PDFDocument();
document._filePath = file.path;
try {
var pageCount = await _channel
.invokeMethod('getNumberOfPages', {'filePath': file.path});
document.count = document.count = int.parse(pageCount);
} catch (e) {
throw Exception('Error reading PDF!');
}
return document;
}

[AdiD253]

Here's the working pubspec dep for a fork with the change above:

advance_pdf_viewer:
  git:
    url: https://github.com/AdiD253/pdf_viewer.git
    ref: pdf-viewer-file-fix

[himalaya-08]

Came across this issue after upgrading to Flutter 2.2.1 and even the same persisted after downgrading it to 2.2.0.

Sol, that worked:

Edited the /flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart

import 'dart:io'; - > import 'dart:io' as io; : line 2

static Future fromAsset(String asset) async {
io.File file; // Edited
try {
var dir = await getApplicationDocumentsDirectory();
file = io.File("${dir.path}/file.pdf"); // Edited
var data = await rootBundle.load(asset);
var bytes = data.buffer.asUint8List();
await file.writeAsBytes(bytes, flush: true);
} catch (e) {
throw Exception('Error parsing asset file!');
}
PDFDocument document = PDFDocument();
document._filePath = file.path;
try {
var pageCount = await _channel
.invokeMethod('getNumberOfPages', {'filePath': file.path});
document.count = document.count = int.parse(pageCount);
} catch (e) {
throw Exception('Error reading PDF!');
}
return document;
}

This has to be fixed asap.

[kushalmahapatro]

Came across this issue after upgrading to Flutter 2.2.1 and even the same persisted after downgrading it to 2.2.0.
Sol, that worked:
Edited the /flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart
import 'dart:io'; - > import 'dart:io' as io; : line 2
static Future fromAsset(String asset) async {
io.File file; // Edited
try {
var dir = await getApplicationDocumentsDirectory();
file = io.File("${dir.path}/file.pdf"); // Edited
var data = await rootBundle.load(asset);
var bytes = data.buffer.asUint8List();
await file.writeAsBytes(bytes, flush: true);
} catch (e) {
throw Exception('Error parsing asset file!');
}
PDFDocument document = PDFDocument();
document._filePath = file.path;
try {
var pageCount = await _channel
.invokeMethod('getNumberOfPages', {'filePath': file.path});
document.count = document.count = int.parse(pageCount);
} catch (e) {
throw Exception('Error reading PDF!');
}
return document;
}

This has to be fixed asap.

Submitted a PR containing the fix- #51.

[rsanjuan87]

Came across this issue after upgrading to Flutter 2.2.1 and even the same persisted after downgrading it to 2.2.0.

Sol, that worked:

Edited the /flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart

import 'dart:io'; - > import 'dart:io' as io; : line 2

static Future fromAsset(String asset) async {
io.File file; // Edited
try {
var dir = await getApplicationDocumentsDirectory();
file = io.File("${dir.path}/file.pdf"); // Edited
var data = await rootBundle.load(asset);
var bytes = data.buffer.asUint8List();
await file.writeAsBytes(bytes, flush: true);
} catch (e) {
throw Exception('Error parsing asset file!');
}
PDFDocument document = PDFDocument();
document._filePath = file.path;
try {
var pageCount = await _channel
.invokeMethod('getNumberOfPages', {'filePath': file.path});
document.count = document.count = int.parse(pageCount);
} catch (e) {
throw Exception('Error reading PDF!');
}
return document;
}

This solution doesn't work for me with Flutter 2.2.1

[ERROR:flutter/lib/ui/ui_dart_state.cc(199)] Unhandled Exception: Exception: Error reading PDF! #0 PDFDocument.fromAsset (package:advance_pdf_viewer/src/document.dart:78:7) <asynchronous suspension> #1 _PDFPageState._initPdf (package:catalogo/pdfview.dart:31:17) <asynchronous suspension>

Even with the sample project

[rsanjuan87]

not working on MacOS desktop app
Android and iOS working well

[juscghwe]

Came across this issue after upgrading to Flutter 2.2.1 and even the same persisted after downgrading it to 2.2.0.

Sol, that worked:

Edited the /flutter/.pub-cache/hosted/pub.dartlang.org/advance_pdf_viewer-2.0.0/lib/src/document.dart

import 'dart:io'; - > import 'dart:io' as io; : line 2

static Future fromAsset(String asset) async { io.File file; // Edited try { var dir = await getApplicationDocumentsDirectory(); file = io.File("${dir.path}/file.pdf"); // Edited var data = await rootBundle.load(asset); var bytes = data.buffer.asUint8List(); await file.writeAsBytes(bytes, flush: true); } catch (e) { throw Exception('Error parsing asset file!'); } PDFDocument document = PDFDocument(); document._filePath = file.path; try { var pageCount = await _channel .invokeMethod('getNumberOfPages', {'filePath': file.path}); document.count = document.count = int.parse(pageCount); } catch (e) { throw Exception('Error reading PDF!'); } return document; }

Requires another change to Line 22:
static Future<PDFDocument> fromFile(File file) aync
to
static Future<PDFDocument> fromFile(io.File file) aync

Sadly still not working with Exception Error parsing asset file! with example code provided by the package.