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python-microscope / microscope

Python library for control of microscope devices, supporting hardware triggers and distribution of devices over the network for performance and flexibility.
https://www.python-microscope.org
GNU General Public License v3.0
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Linkam stage is missing pyro expose #117

Closed iandobbie closed 4 years ago

iandobbie commented 4 years ago

When we connect from cockpit (updated to lastest master 7/11/2019) with linkam stage on microscope (also latest master) we get...

File "C:\Program Files\Python37\lib\site-packages\Pyro4\core.py", line 280, in getattr raise AttributeError("remote object '%s' has no exposed attribute or method '%s'" % (self._pyroUri, name)) AttributeError: remote object 'PYRO:LinkamBase@192.168.0.10:8001' has no exposed attribute or method 'get_position'

carandraug commented 4 years ago

The lack of Pyro4.expose should not make a difference because deviceserver runs with REQUIRE_EXPOSE set to False.

carandraug commented 4 years ago

I see the problem. The deviceserver is serving an instance of LinkamBase instead of LinkamCMS. Maybe we should mark LinkamBase class as private?

iandobbie commented 4 years ago

Maybe so but the issue boils down to user error, maybe due to inadequate documentation, user training, or just the fact I didn't read any documentation which does exist? I think as it was a config error we should close the issue.

carandraug commented 4 years ago

On the client side, Pyro jst says that the method is not being exposed. The client does not know whether it is because of a missing exposed or not existing at all on the server side. Maybe we can have cockpit check for the presence of all abstract methods which would give a nicer earlier error.

But if LinkamBase is only meant to be used inside the linkam module, marking it as private will help prevent this specific issue.

But yeah, for the most complex modules, it's not always clear which of the classes is meant to be served and the lack of documentation just makes it worse.

mickp commented 4 years ago

Base classes made private in d9cb040f896543a47e84a1ef588fa78415c6bacb .