Is it possible to keep the cache alive?

[luthianovolters]

First, thanks for this awesome package, it's helping me a lot!

I am using this package on flutter web to display an uploaded PDF file with Uint8List on a new screen, but it always clears the cache after the first build of PdfViewer.data().

Note 1: it only clears the Uint8List in the class and in my custom controller with Provider, but the string name is kept in both;
Note 2: it only occurs with PdfViewer; Image.memory() does not clear the data;

Context of use: I'm looking for a solution to navigate to a new screen to display the PDF file and then return to the previous page so the user can save the file.

import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:pdfrx/pdfrx.dart';

class ExampleViewer extends StatelessWidget {
  final String fileName;
  final Uint8List fileBytes;
  const ExampleViewer(
      {super.key, required this.fileName, required this.fileBytes});

  bool _isPDF() {
    return fileName.contains('pdf');
  }

  @override
  Widget build(BuildContext context) {
    return SafeArea(
        child: Scaffold(
            appBar: AppBar(title: const Text('Example Viewer')),
            body: _isPDF()
                ? PdfViewer.data(
                    fileBytes,
                    sourceName: fileName,
                  )
                : Center(child: Image.memory(fileBytes))));
  }
}

Need your help @espresso3389

[eduardogcorrea]

First, I'm learning (and I my language is portuguese, so, try not note my english faults).

I solve that using flutter_cache_manager.

I load the PDF into cache_manager and get the PDF stored into the PDFRX.
Bellow is my code (is under construction, this not have a proper loader / downloader indicator) but I think this maybe helpful.

import 'package:flutter_cache_manager/flutter_cache_manager.dart';

...

class _LeitorpdfState extends State<Leitorpdf> {
  final cacheManager = DefaultCacheManager();
  var pdfFileG = '';

  @override
  void initState() {
    super.initState();
    _loadPDF();
  }

...

 _loadPDF() async {
    var file = await cacheManager.getSingleFile(widget.url); //Get and load file from URL
    var fileKey = await cacheManager.getFileFromCache(widget.url); // Get filekey
    var fileFromCache = fileKey?.file.path; // Get file stored path

    setState(() {
      pdfFileG = fileFromCache!; // Set State from filepath
    });
  `}`

And then, use pdfFileG to show the file

PdfViewer.file(pdfFileG)

With this, the cache is stored in the flutter_cache_manager and can be retrieved in any screen. Its just needed open an cache instance.

As suggestion, the developers @espresso3389 maybe add a storage cache function / controllers. This will be perfect.