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.
In this article we'll review general approach to working with the best kind of projects - the ones with old untested and undocumented spaghetti code and a tight schedule. We'll review anger management techniques, coping mechanisms and some refactoring tips that might come in handy.
We often handling API server updates including backwards-incompatible changes when upgrading web applications. At the same time we update the client part, therefore, we did not experience any particular difficulties.
I've created this small sprite to create css sprites. It glues images from directory directory into single file and generates corresponding css.
In my current project I had a task to use twitter API. Twitter uses OAuth for authentication, which is pretty dreary. To avoid fiddling with it all the time, I've moved authentication to decorator. If key is available - nothing happens, just view is launched as usual. It's convenient that there's no need for additional twitter settings in user profile. Code is in article.