How to order_by() last content `saved` in Admin Dashboard rather than by `date` or `id`.

[Drone4four]

I feel Django docs are sparse and not detailed enough for me to see how to call the LogEntry properly. So I went looking on Google for examples on how to query my db and sort the output of the data according to when a LogEntry ‘CHANGE’ action takes place and then Django serves the template. There were lots of 10+ year old Stack Overflow questions and even those didn’t really answer the question I am looking for.

Here is one of the models I am working with now for my web app:

from django.contrib.admin.models import CHANGE, LogEntry
 
class ScriptSuggestion(LogEntry,models.Model):
   # id = models.IntegerField(blank=False, null=False)
   title = models.CharField(max_length=300,blank=True)
   body = models.TextField(max_length=300000,blank=True)
   author = models.CharField(max_length=300,blank=True)
   slug = models.SlugField(unique=True,blank=True)
   changed = LogEntry.objects.filter(action_flag=CHANGE,blank=False, null=False)
  
   def __str__(self):
       return f'{self.title}'
 

Notice the last declared attribute I’ve called: changed. That is where I believe is the right place to call the LogEntry model.

Here is my corresponding CBV:

class ContentListView(LoginRequiredMixin,ListView):
   model = Content
   def get_context_data(self, **kwargs):
       # Call the base implementation first to get a context
       context = super(ContentListView, self).get_context_data(**kwargs)
       # Add in a QuerySet of all the Baklawa
       context['inductions'] = Induction.objects.all()
       context['preambles'] = Preamble.objects.all()
       context['research'] = Research.objects.all()
       context['scriptsuggestions'] = ScriptSuggestion.objects.all().order_by('-changed')
 
       context['stockscripts'] = StockScript.objects.all()
       return context

Notice the context dictionary keyword argument showing: 'scriptsuggestions'. I’ve appended .order_by('-changed') to the end which is also my best attempt at putting the LogEntry’s model attribute reference in the right place.

There are now two major issues I’ve encountered with the above arrangements:

1. When I created the db migrations initially, it prompted me to enter a default value. The message suggested entering timezone.now. I’ve seen this before so I went ahead and entered it. Big mistake. Afterwards if I recall correctly Django was saying that the id needs to be an integer. Below was the Django traceback. I invoked the Django shell and tried to manually re-assign an integer value to the id attribute for this class instance to replace the erroneous date data. But that didn’t work. Afterwards I added blank=False, null=False to the LogEntry attribute in models.py but it’s too late. Here was the error:

    raise FieldError(
django.core.exceptions.FieldError: Local field 'id' in class 'ScriptSuggestion' clashes with field of the same name from base class 'LogEntry'.

So while I still need to resolve the issue outlined above, now I have got a new issue that needs to be resolved first:

2. I am not sure what I did exactly to trigger it but now the Django dev server log is showing:

File "/home/<user>/dev/projects/python/2018-and-2020/hypno_juicer/venv/lib/python3.10/site-packages/django/apps/registry.py", line 143, in check_models_ready
    raise AppRegistryNotReady("Models aren't loaded yet.")
django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet.

The most upvoted questions on Stack Overflow for this new second issue point to a misconfigured asgi.py.

In another Django forum thread @jeff answered a similar question 3 years ago writing:

@jeff

Django needs to load all of the apps before you can work with them. So adding code which queries the database below your model definitions throws this error. For more details, check out https://docs.djangoproject.com/en/2.2/ref/applications/#how-applications-are-loaded

Thankfully, the fix is to move the non-model code into a ready() method so that the code is ran immediately after Django has loaded everything into memory and your database is ready. Check out https://docs.djangoproject.com/en/2.2/ref/applications/#django.apps.AppConfig.ready(https://docs.djangoproject.com/en/2.2/ref/applications/#django.apps.AppConfig.ready) for more details.

The Django doc referred to is for AppConfig methods. I’m not sure why this is a problem all of a sudden or what I did to cause this. Should I begin building an AppConfig Django app?