[webview_flutter] Add file upload on Android

[dupuchba]

Currently on Android nothing happens for <input type="file"> This PR solves that by registering the callback onShowFileChooser on the WebView that must returns a Future<List<String>> (list of file path). It lets you use which-ever file-provider plugin you want to use as recommended by @stuartmorgan here.

Status:

• [X] Tried it with [image_provider] and it's working
• [ ] Before diving into tests, I hope to have feedbacks on the implementation.
• [ ] Need to read all Contributor guides

Thanks all

Related issues

#3225 https://github.com/flutter/flutter/issues/27924

Pre-launch Checklist

• [ ] I read the Contributor Guide and followed the process outlined there for submitting PRs.
• [x] I read the Tree Hygiene wiki page, which explains my responsibilities.
• [x] I read and followed the relevant style guides and ran the auto-formatter. (Unlike the flutter/flutter repo, the flutter/plugins repo does use dart format.)
• [ ] I signed the CLA.
• [X] The title of the PR starts with the name of the plugin surrounded by square brackets, e.g. [shared_preferences]
• [X] I listed at least one issue that this PR fixes in the description above.
• [ ] I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or this PR is exempt from version changes.
• [ ] I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style.
• [ ] I updated/added relevant documentation (doc comments with ///).
• [ ] I added new tests to check the change I am making, or this PR is test-exempt.
• [ ] All existing and new tests are passing.

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[Hixie]

@dupuchba Are you interested in following-up with the narrower scope @bparrishMines suggested above?

[dupuchba]

@dupuchba Are you interested in following-up with the narrower scope @bparrishMines suggested above?

Yes I am, I was thinking at adding this when @bparrishMines work would be ready :-) !

[Shubhankt1]

Hi @dupuchba I had a good working WebView (webview_flutter: ^2.0.4) and I had implemented file upload as well (based on https://github.com/flutter/plugins/pull/3225), but after I updated to API version 31, I got the whole new architecture and the whole file upload issue is broken and without knowing that this happened I have released the new app version to public.

I need a way out ASAP. Could you guide me where do I make the change? I am all confused looking at the new arch.

[UPDATE]: I made the changes to the package based on your changes and still it doesn't work.

[dupuchba]

hey @Shubhankt1 I am going on holidays and I don't have the time to get back at this issue. Last April I said I would make a PR with the new plugin architecture for flutter_webview, once it's done. If you want to make it work it's pretty straightforward, plus you have my PR as an example. Basically I just wrote some platform code for this method https://developer.android.com/reference/android/webkit/WebChromeClient.html#onShowFileChooser(android.webkit.WebView,%20android.webkit.ValueCallback%3Candroid.net.Uri[]%3E,%20android.webkit.WebChromeClient.FileChooserParams)

[stuartmorgan]

Status update from triage: Still blocked on https://github.com/flutter/flutter/issues/94051, but we hope to have that resolved soon.

[godilite]

Isn't it frustrating that if this a solution, it cannot be merged for everyone to use?

[dupuchba]

@godilite to be faire I've not updated my commit to the new platform infrastructure. And I personally don't think it's frustrating, you can still contribute and make it a reality !

[rashidotm]

Hi.

I am happy to see https://github.com/flutter/flutter/issues/94051 merged which was blocking this.

Now, is there a timeframe for when this will be closed? I am holding an update to my app based on your comments.

thanks and best.

[dupuchba]

@rashidotm excellent news ! I am probably going to address this in January 23

[bparrishMines]

@dupuchba Thanks for your contribution and patience! I had time to work on this, so I went ahead and created https://github.com/flutter/plugins/pull/6881, that uses the new infrastructure of the plugin. I'm going to go ahead and close this one in favor of the other.

[dupuchba]

@bparrishMines thanks a lot for your time and work. For what it's worth, it was still on my daily reminder (but I kept pushing it) ^^