First of all, you lack permission in the apparmor file.
content_exchange_source

Then you're not doing anything, so I suppose this is just a simple inheritance from Morph Browser that do not share the file as intended.
I never tried webapp so I don't know how to actually do it, but I guess you'll have to somehow to overload the class in order to specify that you are sharing a picture...

You will have to give something to the Content Hub like the code snippet about onExportRequested here: https://ubports.gitlab.io/docs/api-docs/?p=lomiri-content-qml-api%2Fqml-lomiri-content-contenthub.html#detailed-description

You can also try the telegram group if you cannot find more help here on the forum: https://t.me/UbuntuAppDevEN

Good luck.

Sure, I understand it's easier to start with a basis you master.
I personally forced myself to use pure QML as much as I can to teach me how it works.
And we have people that can help as well as good example to borrow some code.

Thanks for your contribution, it's always appreciated.
People usually agree that we need more native apps for Ubuntu Touch.

For exporting, I will let the user tap the document in the download pop-up, and the webview will handle exporting. I tested it, and it seems to export as intended.

I really should switch my app to use QML with a WebView object, but unfortunately I'm not remotely familiar enough with QML to implement it without help.

If you (or any passerby) is curious about the app in question, it's here: https://github.com/Semphriss/Annotate. I'll upload it to the Open Store in a few days, after fixing the last few rough edges.

Thanks again for the help! I'll see if I can switch this thread to a Q&A one so that I can accept your answer.

First of all, you lack permission in the apparmor file.
content_exchange_source

Then you're not doing anything, so I suppose this is just a simple inheritance from Morph Browser that do not share the file as intended.
I never tried webapp so I don't know how to actually do it, but I guess you'll have to somehow to overload the class in order to specify that you are sharing a picture...

You will have to give something to the Content Hub like the code snippet about onExportRequested here: https://ubports.gitlab.io/docs/api-docs/?p=lomiri-content-qml-api%2Fqml-lomiri-content-contenthub.html#detailed-description

You can also try the telegram group if you cannot find more help here on the forum: https://t.me/UbuntuAppDevEN

Good luck.

Here's a basic reproducible project: https://gitlab.com/Semphriss/ut-webapp-contenthub

The first commit is a basic project as generated by Clickable, all the defaults except the project type set to HTML. I did not change any file.

The second commit is the basic steps I followed to attempt to make it work, which will give the same behavior as I described.

Do you have a repository we can access to see your code and try to help?
What comes to mind is probably an issue with the file path or an issue in the apparmor file...

I have no direct experience with the Content Hub but I know that filepath can be confusing...