Resource editor raises KeyError when switching languages

[jacobtylerwalls]

1. Enable the language switcher an additional language
2. Save a new resource model instance
3. Change to that language

Internal Server Error: /resource/44490b12-feb3-4b09-977c-8b15588baea4
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
  File "/usr/local/lib/python3.10/dist-packages/django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/views/generic/base.py", line 104, in view
    return self.dispatch(request, *args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/utils/decorators.py", line 46, in _wrapper
    return bound_method(*args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/contrib/auth/decorators.py", line 23, in _wrapper_view
    return view_func(request, *args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/views/generic/base.py", line 143, in dispatch
    return handler(request, *args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/django/utils/decorators.py", line 46, in _wrapper
    return bound_method(*args, **kwargs)
  File "/web_root/arches/arches/app/utils/decorators.py", line 82, in wrapper
    return function(request, *args, **kwargs)
  File "/web_root/arches/arches/app/views/resource.py", line 277, in get
    serialized_graph = published_graph.serialized_graph
AttributeError: 'NoneType' object has no attribute 'serialized_graph'

Tested with afs
Version 7.5 dev

[jacobtylerwalls]

Can still reproduce

[chrabyrd]

Can you add the steps to reproduce?

[jacobtylerwalls]

Looks like the OP was missing a step. (sorry!)

1. Publish a graph
2. Add a new language to settings.py that wasn't there before
3. Rebuild webpack and refresh
4. Create an instance of that graph
5. Switch to the language you added in step 2

Now it strikes me that the problem goes away if I run manage.py graph publish --update after adding the new language. If this is a requirement, we should document it, I figure?

I'll also update the traceback, which is a little different now.

[jacobtylerwalls]

Looks like I was a little confused about whether the error emanated from the graph designer or the resource instance editor. Looks like it's only emanating from the latter now. I'll retitle.

[chrabyrd]

Looks like the OP was missing a step. (sorry!)

1. Publish a graph
2. Add a new language to settings.py that wasn't there before
3. Rebuild webpack and refresh
4. Create an instance of that graph
5. Switch to the language you added in step 2

Now it strikes me that the problem goes away if I run manage.py graph publish --update after adding the new language. If this is a requirement, we should document it, I figure?

I'll also update the traceback, which is a little different now.

No worries!

The Graph.publish command iterates settings.LANGUAGES and not the languages table so there's not really anything to hang a trigger onto. Also automatically triggering a serialized save could result in unpredictable behavior. So yeah this looks to be a documentation issue. Alternatively I'm going to put a small timebox on this and investigate how easy it would be to gracefully fall back to the un-serialized graph.

[jacobtylerwalls]

Nice. In terms of documentation, I bet you could throw a system check from the PublishedGraph class that tells you to run the update command if you're missing publications for some language. There's a little example here. Then you wouldn't even be able to runserver if you end up in this situation.

[chrabyrd]

@jacobtylerwalls I've assigned a PR to you here #10652 that should address the issue.

Unfortunately I couldn't override the check attr on models without making it a class method, and as a class method we can't check any specifics about the actual graph. This worked locally for me and hopefully it should work on yours as well but let me know. I also removed the raise_if_missing arg since with this change there isn't a conceivable way to accidentally have an unpublished graph ( as far as I know ). However if it needs to be re-added please let me know.