[share_plus] share() result in empty message in Facebook News Feed

[Ciock]

System info

Issue occurs on: both
Plugin name: share_plus
Plugin version: 2.1.4
Flutter doctor output:

[√] Flutter (Channel beta, 2.4.0-4.2.pre, on Microsoft Windows [Versione 10.0.19043.1165], locale it-IT)
[√] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
[√] Chrome - develop for the web
[√] Android Studio (version 4.1.0)
[√] IntelliJ IDEA Ultimate Edition (version 2020.1)
[√] VS Code (version 1.59.0)
[√] Connected device (3 available)

• No issues found!

Steps to Reproduce

1. Share.share('text');
2. Select Facebook News Feed
3. Then the Facebook post textfield is empty with the placeholder "What's on your mind?"

It is quite a serious problem because I have been contacted by the Facebook Team regarding this feature which does not respect their policies:

Developer Policy 1.2: Build an app that is stable and easily navigable.Some common violations of this policy include:

• Broken Facebook integration (e.g. broken share, like or comment functionality)
• Broken user experience in the app (e.g. app has broken links or user interface failures)

[Boehrsi]

I did some research regarding this topic (if someone knows other / more information please correct me) and it seems like it's not working with this plugin (or with the whole native Android sharing concept in general) as Facebook decided to not implement / block the normal sharing flow. Keeping this in mind it's actually hilarious that Facebook is blaming you that stuff is not working.

My findings:

• Facebook doesn't support share via Intent which is the Android way of sharing content
• Facebook has it's own SDK with sharing functionality https://developers.facebook.com/docs/sharing/ / https://github.com/facebook/facebook-android-sdk
• There are other plugins handling the Facebook specific part (not checked for quality just listing some) and all of them require e.g. a Facebook SDK specific key
  • https://pub.dev/packages/flutter_share_me
  • https://pub.dev/packages/flutter_social_content_share
  • https://pub.dev/packages/social_share_plugin

Even though Facebook is a big player as company and in the internet, this is really really bad!

The SDK contains a lot of stuff and potentially analytics and what so ever.
@mhadaily I would highly vote (even though I potentially have no vote here 😄) against including such a potentially big dependency and app specific code just because a company decides it's big enough to not support the normal default workflows.
@Ciock I think the best approach for you would be evaluating one or another of the mentioned plugins if those support your use cases.

iOS: I can't say something specific regarding iOS, as I'm mostly an Android developer, but I would assume something similar is the problem on iOS. Potentially there is also an SDK or something.

[jasonJamEther]

I am getting the same result on ios when sharing to facebook messenger.
Share.shareFiles([file.path], text: 'share text goes here');
results in the image appearing as expected in messenger but the message text is empty.

[Ciock]

Thank you @Boehrsi, your comment is really helpful to understand better where is the problem 🙏

I tried those plugins that you cited, but the first two have problems with Android 11 and also already have issues opened about this, the last one is not mantained and is not updated to dart null safety.

By now I removed the whole share functionality in my app, because I can't risk losing the login via Facebook because of them policies

[Boehrsi]

You are welcome @Ciock I'm happy I could provide some information and I'm sorry that the other libraries aren't helpful.

@mhadaily Could it be a good idea to document this topic? I could provide a PR to avoid more confusion in this area.

[mhadaily]

@Boehrsi sure, a good documentation is the key.

[vinnytwice]

@Boehrsi HI I'm getting to code the sharing part for my app but I don't yet really master the whole process..
I'm a bit confused about how to handle the sharing problem with Facebook as experienced by @Ciock. If I got it right this problem is only on Android as with share_plus package the sharing would be carried out via Intent but Facebook doesn't accept them and any content share will cause problems with Facebook ( eg brake the dev policy as mentioned by @Ciock) when Facebook is the app receiving the Intent.
So if Facebook is gonna give problems to everybody wouldn't be possible to either bridge native Facebook SDK or exclude Facebook from sharing capabilities in this package with Intent.EXTRA_EXCLUDE_COMPONENTS or are you looking to solve thins in other ways? Otherwise the whole sharing on Flutter gets impossible to implement.. well at least in a native looking manner.
I saw that the other mentioned packages have their defined methods to be called for specific apps..so you can't use the Android Sharesheet and need to build a custom UI for sharing which is rather ugly and discouraged practice from Android docs..