Pass an object as argument with gdbus utility

I want to call method RegisterAgent with gdbus but I can't find the proper syntax to do so.

Introspecting on /org/bluez with this command

$ gdbus introspect --system --dest org.bluez --object-path /org/bluez --recurse

shows that method RegisterAgent on interface org.bluez.AgentManager1 has the following signature:

RegisterAgent(in  o agent,
              in  s capability);

but I can't find any example showing how to pass an object to a method in the gdbus reference documentation, nor in the numerous examples I've found on the Internet.

So I don't know how to pass an agent as first argument, for example I'd like to select KeyboardOnly as agent, but how can this be done?

With dbus-send, this gives:

dbus-send --print-reply --system --dest=org.bluez /org/bluez \
    --type=method_call org.bluez.AgentManager1.RegisterAgent \
    objpath:/org/bluez/agent1 string:KeyboardOnly

But I can't find how to do this with a gdbus call. Any idea?

Solution

I spied on the actual commands sent through DBus using

dbus-monitor  --system

With trial and error, I finally found the correct syntax.

The gdbus command I was trying to make can be spelled like so:

gdbus call --system --dest org.bluez --method \
    org.bluez.AgentManager1.RegisterAgent --object-path /org/bluez \ 
    /org/bluez/agent KeyboardOnly

So passing an object as parameter to gdbus is done by spelling its path, for instance /org/bluez/agent in our case. It seems to me this is not documented.

By the way, the corresponding dbus-send command is spelled almost the same

dbus-send --print-reply --system --dest=org.bluez /org/bluez \
    --type=method_call org.bluez.AgentManager1.RegisterAgent \
    objpath:/org/bluez/agent1 string:KeyboardOnly

but for the agent object path... /org/bluez/agent1 for dbus-send, and just /org/bluez/agent for gdbus. I don't think this aspect is documented either.