openplotterCan.py UnboundLocalError: local variable 'data' referenced before assignme

[whoswho]

Hi

I've just installed openplotter-settings on ubuntu 22.04
I then installed CAN Bus 4.1.0-stable

when I press "open" to run it, I get the following dump on the console:

Traceback (most recent call last):
  File "/usr/bin/openplotter-can", line 11, in <module>
    load_entry_point('openplotterCan==4.1.0', 'console_scripts', 'openplotter-can')()
  File "/usr/lib/python3/dist-packages/openplotterCan/openplotterCan.py", line 1552, in main
    MyFrame().Show()
  File "/usr/lib/python3/dist-packages/openplotterCan/openplotterCan.py", line 94, in __init__
    self.pageSk()
  File "/usr/lib/python3/dist-packages/openplotterCan/openplotterCan.py", line 180, in pageSk
    self.readSk()
  File "/usr/lib/python3/dist-packages/openplotterCan/openplotterCan.py", line 190, in readSk
    if 'pipedProviders' in data:
UnboundLocalError: local variable 'data' referenced before assignment
Terminated


I am not really a Python expert, but I belive that a patch like the following could fix the problem (at least it looks like it fixed for me)

Code:

--- /usr/lib/python3/dist-packages/openplotterCan/openplotterCan.py-orig    2024-11-04 16:27:50.523849784 +0100
+++ /usr/lib/python3/dist-packages/openplotterCan/openplotterCan.py    2024-11-04 16:29:34.789978732 +0100
@@ -181,9 +181,9 @@

    def readSk(self):
        self.sklist = []
+        data = ''
        try:
            setting_file = self.platform.skDir+'/settings.json'
-            data = ''
            with open(setting_file) as data_file:
                data = ujson.load(data_file)
        except:pass

Thank you for your work

Bye

[Sailoog]

Is Signal k installed from openplotter-signalk-installer app?

[whoswho]

Thank you for your reply

I deleted all the openplotter packages and reinstalled everything

As a matter of fact if I run openplotter-signalk-installer before installing and running "CAN bus", I don't get the error

Perhaps I did not understand this in the documentation but, if that is a pre-required step, maybe it could be enforced in the setup procedure

Thank you again

[Sailoog]

You can not set any CAN device without Signal k server installed.

when you install openplotter-can, openplotter-signalk-installer gets also installed as dependency. Signal k server gets installed the first time you open openplotter-signalk-installer.

We may need some code to check if SK server is installed and generate an error message.