Proposal to homogenize the examples

[ampuEus]

I have been using OPC UA for some time and I have seen that the examples do not have a homogeneous structure and a short introductory description explaining what is searched for each example (apart from the file name itself).

As a new user, it took me a bit to get used to them and my idea with this post is to see if you would like me to review the examples so that they all have a structure as similar as possible and with a small description so new users have it easier.

For example:

• Sometimes, the "logging" is configured at the beginning of the program after importing the modules and other times in between or _logger.info ('Starting server!') Is sometimes set and sometimes not
• Sometimes the formula asyncio.run (main ()) is used and other times asyncio.run (main (), debug = True)
• The certificates and the programs to generate them could be in a folder instead of mixed with other examples that do not use them
• etc.

So If you want I can open a pull request and start making these little changes to see if they seem good to you.

P.S.: Since I have been using this library, I would like to contribute something. But I know that my level today is not up to being able to implement the OPC UA standard (alarms, XML protocol, session restore...). Even so, I think I could take away simpler jobs like this one that I'm proposing. Or some other task that, even though it is easy, you do not have the time to do it.

[oroulet]

you are welcome! starting with the example is a good idea. a merge request is more than welcome.
Maybe you should write down here the main things you want to change.

also

• logging MUST be configured AFTER "if name == "main"

[ampuEus]

My idea is to start with these changes:

1. Sometimes for the same piece of code each example has a different comment
For example:

    # setup our own namespace, not really necessary but should as spec
    uri = 'http://examples.freeopcua.github.io'
    idx = await server.register_namespace(uri)

Sometimes it only appears # setup our own namespace and other times it doesn't even appear.

2. Put all certificates in the same folder and the same with the xml
My directory proposal:

 - examples
    - certificates
         - peer-certificate-example-1.der
         - peer-certificate-example-2.der
         - peer-certificate-example-3.der
         - peer-certificate-example-encrypted-private-key.der
         - peer-certificate-example-1.pem
         - peer-certificate-example-2.pem
         - peer-certificate-example-3.pem
         - peer-certificate-example-encrypted-private-key.der
         - certificate-3072-example.der
         - certificate-example.der
         - generate_certificate.sh
         - private-key-3072-example.pem
         - private-key-example.pem
  - xml custom models
         - custom_nodes.xml
         - customobject.xml

Of course, I have to see what parts of the code use these files and change their address to this new one.

3. Put the logger in the right place
4. Use this structure for all the examples:

• Describe the purpose of the example
• Import non-asyncua modules
• Import asyncua modules
• Example classes (If it has them)
• Example functions (If it has them)
• The main function
  - loggger
  - server setup
  - namespace
  - [specific code of the example]
  - start server
• And the run

if __name__ == "__main__":
         logging.basicConfig(level=logging.INFO)
         asyncio.run(main())