Web-browsers, like chromium, want to know if they are configured as the preferred application used in the desktop-environment. Currently, exo does not provide an interface to determine the preferred webbrowser, for example.
That is why I propose a query mechanism to determine the preferred application.
Created attachment 4268
Patch to add --query option to exo-helper
Another thought on this bug, maybe you want --get and --set functions, so a browser can choose to configure itself as the default if the user chooses it.
I doubt exo-open will be any standard, so maybe this is not the right place. Sound more like an xdg discussion how to implement this.
Stephan Arts referenced this bugreport in commit e9fb7651e209862b2821db5ed8e73075bf8f05d4
Add a query mechanism to determine the preferred application (Bug #8579)
This patch is lightweight and does provide some added usefulness for exo. Applied in the above commit.