fix(client): Ensure that the bus is connected before pairing

[pmessan]

If pairing is attempted before the bus is connected, the pairing process fails due to an exception being raised.

[dlech]

Can you please describe how to reproduce the problem that this is fixing?

[pmessan]

On a Linux system:

1. Enable discovery (have a device ready to pair / connect)
2. When device is discovered, in line with the documentation of BleakClientBlueZDBus.pair(), trust device, then pair, then connect.
3. Calling BleakClientBlueZDBus.pair() on a Linux-based central will cause an error similar to Object None has no attribute 'call'.
4. This is because, in BleakClientBlueZDBus.pair() we use the bus connection without checking if it exists whereas for example in BleakClientBlueZDBus.connect(), (here), the bus connecion is initialized the before proceeding with the BLE connection. This means if you call pair() before you call connect(), an exception will be raised.

[dlech]

OK, so I think what we really want here is to solve #309 where we can just call pair() instead of connect().

Or perhaps even better, add a pair=True paramter to the connect() method and also the BleakClient() constructor.

[pmessan]

OK, so I think what we really want here is to solve #309 where we can just call pair() instead of connect().

Or perhaps even better, add a pair=True paramter to the connect() method and also the BleakClient() constructor.

Has anyone attempted to solve this already?
Also, since the pair method is currently broken and does not work without a workaround, would it make sense to fix that then tackle the enhancement as described? Currently with this workaround on my local system I can call pair()(to enable secure connections) then connect() with success.

[dlech]

Also, since the pair method is currently broken and does not work without a workaround, would it make sense to fix that then tackle the enhancement as described

I don't think it is broken. Everyone so far connects first, then pairs.

[pmessan]

Also, since the pair method is currently broken and does not work without a workaround, would it make sense to fix that then tackle the enhancement as described

I don't think it is broken. Everyone so far connects first, then pairs.

But that's in direct contrast to the documentation of that method 😄

[dlech]

But that's in direct contrast to the documentation of that method 😄

Can you share a link? I'm not finding that.

[pmessan]

Additionally, per my testing, calling pair() which calls the Pair method on the BlueZ device, triggers a connection attempt from the Linux host to the remote host by itself anyways.

[pmessan]

But that's in direct contrast to the documentation of that method 😄

Can you share a link? I'm not finding that.

bleak/bleak/backends/bluezdbus/client.py

Line 433 in e01e264

Else you need to StartDiscovery, Trust, Pair and Connect in sequence.