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
Promise is a powerful tool in asynchronous programming that allows developers to call a time-consuming function and proceed with program execution without waiting for the function result.
In one of our recent projects, we had an interesting case: the whole application was built around an interactive map for a fairly large shopping mall, and the main goal of the system was to plot the closest route to a user-selected destination.
One of the key requirements for modern UI is being performant. No matter how beautiful your app looks and what killer features it offers, it will frustrate your users if it clangs.
Designing database architecture is a challenging task, and it gets even more difficult when your app keeps getting bigger. Here are several tips on how to manage your data structure in a more efficient way.
File upload works differently from simple form inputs, which can be somewhat troublesome for beginners. Here I'll show you how to handle uploads with ease.
There are two most popular web frameworks in Python. There is the Django with lots of intelligent defaults and the Flask micro framework with complete freedom in the choice of modules. Let’s see, what django vs flask is in 2017.
