InAppWebView - How to enable download files in WebView

InAppWebViewOnDownloadStartExample.dart

import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter_inappwebview/flutter_inappwebview.dart';
import 'package:flutter_downloader/flutter_downloader.dart';
import 'package:path_provider/path_provider.dart';
import 'package:permission_handler/permission_handler.dart';

Future main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await FlutterDownloader.initialize(
      debug: true // optional: set false to disable printing logs to console
  );
  await Permission.storage.request();
  runApp(MyApp());
}

class MyApp extends StatefulWidget {
  @override
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> {
  InAppWebViewController _webViewController;

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('InAppWebView Example'),
        ),
        body: Container(
            child: Column(children: <Widget>[
              Expanded(
                  child: InAppWebView(
                    initialUrl: "http://ovh.net/files/1Mio.dat",
                    initialOptions: InAppWebViewGroupOptions(
                      crossPlatform: InAppWebViewOptions(
                          debuggingEnabled: true,
                          useOnDownloadStart: true
                      ),
                    ),
                    onWebViewCreated: (InAppWebViewController controller) {
                      _webViewController = controller;
                    },
                    onDownloadStart: (controller, url) async {
                      print("onDownloadStart $url");
                      final taskId = await FlutterDownloader.enqueue(
                        url: url,
                        savedDir: (await getExternalStorageDirectory()).path,
                        showNotification: true, // show download progress in status bar (for Android)
                        openFileFromNotification: true, // click on notification to open downloaded file (for Android)
                      );
                    },
                  ))
            ])),
      ),
    );
  }
}

I have followed the example above. And the code is like this:

/// on crossPlatform: InAppWebViewOptions
useOnDownloadStart: true,

onDownloadStart: (controller, url) async {
          Directory tempDir = await getExternalStorageDirectory();
          print("onDownload $url");
          await FlutterDownloader.enqueue(
            url: "$url",
            savedDir: tempDir.path,
            showNotification: true,
            openFileFromNotification: true,
            saveInPublicStorage: true,
          );
        },

But there is no reaction. In the console it just shows up like this:

I/flutter (16534): onDownload https://botmaster-files.s3.ap-southeast-1.amazonaws.com/Content/this-file-to-download.pdf
W/WM-WorkSpec(16534): Backoff delay duration less than minimum value

What is missing? or that I haven't implemented yet?

Hi
When I tried to download a pdf, app getting closed automatically.
Any solution found for this?

Hi When I tried to download a pdf, app getting closed automatically. Any solution found for this?

any solution?

Anyone solved this issue?
even with the new onDownloadStartRequest, the download does not start (with useOnDownloadStart: true, in the options).

this code is not working when there is no any direct url for download files. for example :- link doesn't have any extension like .jpg, .png, .mp3
example.com/file.jpg -- it will work
example.com/file/download -- it will not work

ettings plea

example.com/file/download -- it will not work
any solution?

I believe your server code executing the route /file/download need to specifically return the data as an attache file and specify the text-mime

An updated example can be found here for plugin version 6: https://github.com/pichillilorenzo/flutter_inappwebview_examples/tree/main/file_download

LATEST APPROACH: As at August 2023

//===========START=============
InAppWebViewGroupOptions options = InAppWebViewGroupOptions(
      crossPlatform: InAppWebViewOptions('
        useShouldOverrideUrlLoading: true,
        useOnDownloadStart: true, //======================Very Important
        mediaPlaybackRequiresUserGesture: false,
      ),
      android: AndroidInAppWebViewOptions(
        useHybridComposition: true,
        supportMultipleWindows: true,
      ),
      ios: IOSInAppWebViewOptions(
        allowsInlineMediaPlayback: true,
      ));
//===========END=============



//===========START=============
   InAppWebView(
      .........
      .........
	      onDownloadStartRequest: (controller, url) async {
                    Directory? tempDir =
                              await getExternalStorageDirectory();
                    setState(() {});
                    print(
                        "onDownload ${url.url.toString()}\n ${tempDir!.path}");
                    await FlutterDownloader.enqueue(
                      url: url.url.toString(),
                      fileName: url.suggestedFilename, //================File Name
                      savedDir: tempDir.path,
                      showNotification: true,
                      requiresStorageNotLow: false,
                      openFileFromNotification: true,
                      saveInPublicStorage: true,
                          );
                        },
      .........
      .........
      .........

)
//===========END=============

LATEST APPROACH: As at August 2023

Well it seems the download started but the app crashed showing the error

D/DownloadWorker(26207): Update too frequently!!!!, this should be dropped

how did you made it to work?

            `onDownloadStart: (controller, url) async {
              print("Download Start: $url");
              // Check if the file is a PDF
              if (url.toString().toLowerCase().endsWith('.pdf')) {
                // Open PDF viewer using url_launcher
                // ignore: deprecated_member_use
                if (await canLaunch(url.toString())) {
                  // ignore: deprecated_member_use
                  await launch(url.toString());
                } else {
                  log("Could not launch PDF viewer");
                }
              } else {
                // Launch for other file types
                if (await canLaunch(url.toString())) {
                      await launch(url.toString());
                    } else {
                      log("Could not launch file");
                    }
                //log("Handle other file types or open in-app viewer");
              }
            },`
            try this code it worked for me

i am not able to download if my file is related to blob URL getting below error.

Update notification: {notificationId: 7, title: blob:
"COMPANY URL", status: RUNNING, progress: 0}
D/DownloadWorker( 5399): Update too frequently!!!!, but it is the final update, we should sleep a second to ensure the update call can be processed
D/DownloadWorker( 5399): Update notification: {notificationId: 7, title: blob: "COMPANY URL" status: FAILED, progress: -1}
W/System.err( 5399): java.net.MalformedURLException: unknown protocol: blob

@ranjan51 does this help you pichillilorenzo/flutter_inappwebview#2212 ?