In UNIX way, each view should solve single task. This is good idea, but sometimes we need to mix logic of different views on same page. Filter, sort, paginate, or, for example, add comment on product page. In this article I'll show how we can mix such multiple views.
Idea
We can write views as decorators.
Example
Simplified filtration can look like this:
from django.views.generic.list_detail import object_list
def filtered_list(request, filterset_class, queryset, *args, **kwargs):
filterset = filterset_class(request.GET)
queryset = filterset.filter(queryset)
kwargs['extra_context']['filterset'] = filterset
return object_list(request, queryset, *args, **kwargs)This is simple and straightforward, but in order to add some tricky pagination, we have to copy entire view and add more code to it.
Instead, we can create decorator like this:
def filtered(view):
def wrapped(request, filterset_class, queryset, *args, **kwargs):
filterset = filterset_class(request.GET)
queryset = filterset.filter(queryset)
kwargs['extra_context']['filterset'] = filterset
return view(request, queryset, *args, **kwargs)
return wrappedResult
Assuming, that we have similar decorators, sorted и paginated, we can easily combine them:
@filtered
@paginated
def technic_list(*args, **kwargs):
# ...Or even like this, in lisp style:
url(r'^technic/$', filtered(sorted(paginated(object_list))), {
'filterset_class': FilterSet,
# ...
}, name='technic_list'),Subscribe for the news and updates
This article offers key insights into the ISTQB certification and shares a proven preparation strategy to help candidates succeed.
Django ORM is a very abstract and flexible API. But if you do not know exactly how it works, you will likely end up with slow and heavy views, if you have not already. So, this article provides practical solutions to N+1 and high loading time issues. For clarity, I will create a simple view that demonstrates common ORM query problems and shows frequently used practices.
Programmatic generation of PDF files is a frequent task when developing applications that can export reports, bills, or questionnaires. In this article, we will consider three common tools for creating PDFs, including their installation and converting principles.
In this article I will tell you how to create an interactive interface with a widely customized visual look and different filtering to view reports.
Learn more about how to include jquery plugins in angular 2 running via webpack. Our tutorial is perfect for Angular beginners.
It appears that not everyone knows that in python you can create classes dynamically without metaclasses. I'll show an example of how to do it.So we've learned how to use custom QuerySet to chain requests:Article.objects.old().public()Now we need to make it work for related objects:user.articles.old().public()This is done using use_for_related_fields, but it needs a little trick.