What is the correct way to open URLs from application?

[BryanQuigley]

Trying to figure out the correct way to make a link work (started with flathub/de.uni_heidelberg.zah.GaiaSky#1 links don't work - app I am working on).

Decided to see what other apps do and found
flathub/gedit. Help -> About > gedit.org | opens that webpage as a text file in gedit itself.
flathub/Rhythmbox Help-> About -> Rhythmbox website works as expected.
flathub/LibreOffice links open in external browser correctly
flathub/Steam - links open in external browser correctly

[TingPing]

So the application looks like its written in Java which makes it annoying and I'm not familiar with it. The simple solution is for it to execute xdg-open https://example.org and it will just work inside of Flatpak.

[felipeborges]

clicking on gedit.org opens the website in a browser here too, as expected.

[BryanQuigley]

I've helped find another case where GaiaSky doesn't have working links.

@felipeborges can we compare setups? It's possible that I have something wrong on my system.
Ubuntu 20.10 dev
org.gnome.gedit 3.36.2 stable flathub system
ostree 2020.5-1
xdg-desktop-portal 1.6.0-1
flatpak 1.8.1-2

xdg-open http://www.gedit.org does do the right thing.

[felipeborges]

Gotcha, I was running an older version of gedit. This seems like a regression.

[BryanQuigley]

Upstream (https://gitlab.com/langurmonkey/gaiasky/-/issues/337#note_416407044) traced it to https://hg.openjdk.java.net/jdk/jdk11/file/1ddf9a99e4ad/src/java.desktop/unix/classes/sun/awt/X11/XDesktopPeer.java#l119. What should Java be doing there instead?

[hadess]

Is this really using gnome_url_show() from the 2.x era libgnome? That's been deprecated for the best part of 10 years.

[hadess]

I don't know what Java should be using, but I'm pretty certain that gnome_url_show() didn't know anything about x-scheme-handler

[TingPing]

Java should probably be using g_app_info_launch_default_for_uri_async().

[nbenitez]

Java should probably be using g_app_info_launch_default_for_uri_async().

A more short term solution would be to patch our flathub openjdk extension to use that api or to just launch a xdg-open command. I proposed that on the following issue:
flathub/org.freedesktop.Sdk.Extension.openjdk11#15

[GeorgesStavracas]

Given the proposals above, and the investigation that was done, I'm considering this out of scope for XDG desktop portal