Hi James, thanks a lot for pointing me to the models.Mangager option. Now this is really interesting. I will definetly check out how caching works.
Now the question is: How do I now access the CategoryManager.get_main_category() in my template.html? I guess I have to pass it over to context within the view? Am Sonntag, 18. Januar 2015 12:28:30 UTC+1 schrieb James Schneider: > > If I understand you right, you want to set MAIN_CATEGORY as a "global" > variable/setting containing a Category object with an ID of 1. Is that > right? If so... > > Rather than populating a "global" variable, I would instead create a > custom model manager for the Category model: > > https://docs.djangoproject.com/en/1.7/topics/db/managers/#custom-managers > > It would be a pretty simple override just to add an extra method: > > class CategoryManager(models.Manager): > def get_main_category(self): > return Category.objects.get(pk=1) > > class Category(models.Model): > <...other fields...> > objects = CategoryManager() > > > Then, anywhere you needed the value that would be accessed via > MAIN_CATEGORY, you would instead use 'main_category = > Category.objects.get_main_category()'. > > If you ever need to change the category that is returned, the only place > you'll need to update the code/PK is in the manager method definition. Much > more flexible than a simple variable in settings.py. > > Realize that the example above is quite a naive/simplistic implementation, > and can benefit from other optimizations (such as a basic caching mechanism > in the CategoryManager in the event it is called multiple times during a > request to avoid multiple queries for the same data, among others). Check > out > https://github.com/django/django/blob/master/django/contrib/auth/backends.py#L41 > > for how Django handles caching for permission checks (which are often > called multiple times per request). > > To avoid the dependency on a specific key/PK, you may want to consider > adding a boolean field to Category called 'is_main' that defaults to False. > Then set the field to True for the single category you want to be the main > one. Then your manager query would look like > Category.objects.get(is_main=True). Just make sure you only have one > category with is_main set to True (if you change your mind on which > category will be the main category, set all of the Categories to False, and > then reset the new main category to True). If you are confident that it > will never change, though, you'll probably be fine. > > -James > > > On Jan 18, 2015 2:26 AM, "ThomasTheDjangoFan" < > [email protected] <javascript:>> wrote: > >> Ladies and gentleman, >> >> I am new to Django and would really love to have a solution for this: >> >> My goal is to share generated settings between my views/models and >> templates, without repeating myself. >> >> Right now I have following code, where the problem appears: >> >> #MY_CONTEXT_PROCESSOR.PY >> from django.conf import settings >> >> def setDataToContext (request): >> """ >> Send settings to context of tempalte >> """ >> >> #GENERATED STUFF >> #Prepare common Objects >> main_category = Category.objects.get(id=1) >> >> return { >> 'settings': settings, # Global Django Settings >> 'MAIN_CATEGORY': main_category, # Make category available in >> template - Question: How do I make this available in views/models as >> settings.MAIN_CATEGORY? >> } >> >> >> The main question is: >> >> *How can I make the generic constant MAIN_CATEGORY available in >> views/models as settings.MAIN_CATEGORY without repeating myself?* >> I am really looking forward to see your solutions. >> >> Kind regards >> Thomas >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Django users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> To post to this group, send email to [email protected] >> <javascript:>. >> Visit this group at http://groups.google.com/group/django-users. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/django-users/eb76aeb9-bc51-4b1a-918d-db6d29956d08%40googlegroups.com >> >> <https://groups.google.com/d/msgid/django-users/eb76aeb9-bc51-4b1a-918d-db6d29956d08%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/b364627d-2a43-4569-81f6-35b31e300390%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
