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
Cascading Style Sheets (CSS) made its debut in 1996 and continue to be an indispensable and evolving component of web development. We will examine the most valuable recent and upcoming characteristics in CSS for this year.
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.
There is such a term as Remote Procedure Call (RPC). In other words, by using this technology, programs can call functions on remote computers. There are many ways to implement RPC.
In this article we will write a small library for pulling metadata and creating a preview for a site just like Slack does.
I've created this small sprite to create css sprites. It glues images from directory directory into single file and generates corresponding css.
For local project settings, I use old trick with settings_local file:try:from settings_local import \*except ImportError:passSo in settings_local.py we can override variables from settings.py. I didn't know how to supplement them. For example how to add line to INSTALLED_APPS without copying whole list.Yesterday I finally understood that I can import settings from settings_local:# settings_local.pyfrom settings import \*INSTALLED_APPS += (# ...)