For following Django code using django_rest_framework:
class PollMessageView(generics.ListAPIView):
serializer_class = MessageSerializer
lookup_url_kwarg = 'count'
def get_queryset(self):
count = self.kwargs.get(self.lookup_url_kwarg)
queryset = Message.objects.all()[:count]
return queryset
urlpatterns = [
path('poll_message/<int:count>', PollMessageView.as_view(), name="poll_message"),
]
How do I make the count parameter optional in the URL pattern? For example, if I visit /poll_message/ without a count, it would still call the PollMessageView (and I can set a default number for count if it's missing)?
create a new path as ,
urlpatterns = [
path('poll_message/', PollMessageView.as_view(), name="poll_message-wo-count"),
path('poll_message/<int:count>', PollMessageView.as_view(), name="poll_message"),
]
# URLconf
from django.urls import path
from . import views
urlpatterns = [
path('blog/', views.page),
path('blog/page<int:num>/', views.page),
]
# View (in blog/views.py)
def page(request, num=1):
# Output the appropriate page of blog entries, according to num.
...
In detail reference - https://docs.djangoproject.com/en/3.0/topics/http/urls/#specifying-defaults-for-view-arguments
You can specify defaults for view arguments, but the example on the website is for functional view, not sure how would that work for class based view or in this case, the rest framework class based view.
However, you can add another path with extra options to achieve the same thing
path('poll_message/', PollMessageView.as_view(), {
"count": 5
}, name="poll_message"),
Related
I'm fairly new to django and trying to build a message board app. Everything's been running smoothly up until I tried to add functionality to display a list of posts by author. I got it working but then my post detail view started throwing a 'No User matches the given query. Page Not found 404' error and I can't seem to figure out why. Can anyone help?
views.py
class UserPostList(generic.ListView):
model = Post
# queryset = Post.objects.filter(status=1).order_by('-created_on')
template_name = 'user_posts.html'
paginate_by = 6
def get_queryset(self):
"""
Method to return posts restricted to 'published' status AND to
authorship by the user whose username is the parameter in the
url.
"""
user = get_object_or_404(User, username=self.kwargs.get('username'))
return Post.objects.filter(
status=1, author=user
).order_by('-created_on')
class FullPost(View):
def get(self, request, slug, *args, **kwargs):
"""
Method to get post object.
"""
queryset = Post.objects.filter(status=1)
post = get_object_or_404(queryset, slug=slug)
comments = post.comments.order_by('created_on')
liked = False
if post.likes.filter(id=self.request.user.id).exists():
liked = True
return render(
request,
"full_post.html",
{
"post": post,
"comments": comments,
"liked": liked
},
)
# I'll be adding a comment form in here too
urls.py
urlpatterns = [
...
path('<slug:slug>/', views.FullPost.as_view(), name='boards_post'),
...
path('<str:username>/', views.UserPostList.as_view(), name='user_posts'),
...
]
Error message
(When trying to view a single post (previously working) after adding the UserPostList view and route)
Using the URLconf defined in mhcmsgboard.urls, Django tried these URL patterns, in this order:
1. admin/
2. summernote/
3. register/ [name='register']
4. profile/ [name='profile']
5. login/ [name='login']
6. logout/ [name='logout']
7. new/ [name='create_post']
8. <slug:slug>/update/ [name='update_post']
9. <slug:slug>/delete/ [name='delete_post']
10. <str:username>/ [name='user_posts']
The current path, test-post/, matched the last one.
for <str:name> in path "-" not allowed to use in name,
when you use Slug both paths are equal.
urlpatterns = [
...
path('<slug:slug>/', views.FullPost.as_view(), name='boards_post'),
...
path('<slug:username>/', views.UserPostList.as_view(), name='user_posts'),
]
there are 2 simple ways
use sub path for one or both paths : user_post/<slug:username>/
Use re_path and define the regex to change path
exp:
re_path(r'^(?P\<username>\w+)/$', views.UserPostList.as_view()),
The problem is that you match update_post, delete_post and user_posts URL's to the root. As the error message explains, the current request is made against user_posts. And it seems that you don't have a user called test-post.
You could solve it e.g. with the following URL conf:
urlpatterns = [
...
path('board/<slug:slug>/', views.FullPost.as_view(), name='boards_post'),
...
path('posts/<str:username>/', views.UserPostList.as_view(), name='user_posts'),
...
]
That way, each path is unique and Django knows which View it has to call.
I am retruning all records for specific object in Django successfully.
My url.py is path('city/', views.TestListCity.as_view())
From postman I just GET: http://192.168.99.100:8080/collection/city and it returns all records.
Example:
{
"id": 3,
"name": "Bor",
"region": {
"id": 2,
"name": "Sun"
}
},
Now I want to filter records with column name.
I tried this:
urls.py
path('city/(?P<name>.+)/$', views.TestListCity.as_view()),
views.py
class TestListCity(generics.RetrieveAPIView):
serializer_class = TestListCitySerializer
def get_queryset(self):
name = self.kwargs['name']
return City.objects.filter(name=name)
I try GET:
http://192.168.99.100:8080/collection/city?name=Bor
But then 404:
<title>Page not found at /collection/city</title>
I also tried second approach:
urls.py
path('city/<str:name>/', views.TestListCity.as_view())
views.py
class TestListCity(generics.RetrieveAPIView):
serializer_class = TestListCitySerializer
queryset = City.objects.all()
lookup_field = 'name'
But exactly the same response.
If you want to use the below URL (or its equivalent) where the string is a part of the url matching:
path('city/<str:name>/$', views.TestListCity.as_view()),
Then just call:
http://192.168.99.100:8080/collection/city/Bor/
Instead of:
http://192.168.99.100:8080/collection/city?name=Bor
The later one passes Bor as the value of the name parameter of the GET request, i.e. you will need to use something like name = self.request.GET.get('name') to get the name parameter. It will not be a part of the URL matching.
It's because you used path(), and you wanted a regular expression (re_path()).
Change this:
from django.urls import path
path('city/(?P<name>.+)/$', views.TestListCity.as_view()),
to:
from django.urls import re_path
re_path('city/(?P<name>.+)/$', views.TestListCity.as_view()),
This should work. And maybe the / could be optional, like this: 'city/(?P<name>.+)/?$'
I want to keep my urls dynamic as well as clean.
Therefore I'm using slugs.
My problem right now is, that I get the following error:
redefinition of group name 'slug' as group 2; was group 1 at position 42
I think I get that error, because I have two slugs in my chain.
For reference I have a ListView into ListView into an UpdateView, alls importet from django.views.generic. The first list view gives me the first slug and the update view the second.
Here is the url pattern (spread across the apps):
First list view:
urlpatterns = [
url(r'^$', RestaurantListView.as_view(), name='restaurant-list'),
url(r'^(?P<slug>[\w-]+)/menus/', include('menu.urls', namespace='menu')),
]
Second list view:
urlpatterns = [
url(r'^$', MenuListView.as_view(), name='menu-list'),
url(r'^(?P<slug>[\w-]+)/', MenuUpdateView.as_view(), name='menu-detail'),
]
In the templates I get the objects via:
<li><a href='{{obj.get_absolute_url}}'> {{obj}} </a></li>
Which I have defined in the respective models:
def get_absolute_url(self):
return reverse('restaurants:menu:menu-detail', kwargs={'slug': self.slug})
and
def get_absolute_url(self):
return reverse('restaurants:menu:menu-list', kwargs={'slug': self.slug})
So the resulting pattern at the end is:
restaurants/(?P<slug>[\w-]+)/menus/(?P<slug>[\w-]+)/
How can I fix it so that I don't get the error anymore?
from django.conf.urls import url
from . import views
urlpatterns = [
url(r'^articles/2003/$', views.special_case_2003),
url(r'^articles/(?P<year>[0-9]{4})/$', views.year_archive),
url(r'^articles/(?P<year>[0-9]{4})/(?P<month>[0-9]{2})/$', views.month_archive),
url(r'^articles/(?P<year>[0-9]{4})/(?P<month>[0-9]{2})/(?P<day>[0-9]{2})/$', views.article_detail),
]
for more details https://docs.djangoproject.com/en/1.11/topics/http/urls/
I want to map two or more seller to the same method ecommerce.views.seller. Below is the working code:
urlpatterns = patterns('',
url(r'^(?:store1|store3)/$', 'ecommerce.views.seller'),
)
Is there any way by which I can declare some variable with pattern and simply pass it into urlpatterns. Something like:
SELLER_ID = '?:store1|store3'
urlpatterns = patterns('',
url(r'^(SELLER_ID)/$', 'ecommerce.views.seller'),
)
Just use regular string formatting syntax:
url(r'^({})/$'.format(SELLER_ID), 'ecommerce.views.seller')
You should use capturing groups for regex path variables in order to have them provided as keyword arguments in your view method:
https://docs.djangoproject.com/en/1.10/topics/http/urls/#specifying-defaults-for-view-arguments
There is a very short example at the above link.
What you would probably want to do:
urlpatterns = patterns('',
url(r'^store(?P<pk>[0-9]+)/$', 'ecommerce.views.seller'),
)
in ecommerce/views.py:
def seller(request, pk):
seller = get_object_or_404(Store, pk=pk) # if DB object
# or if not in DB then just use the number
# do your stuff
return response
or use a generic view if the PK points to a DB model:
urlpatterns = patterns('',
url(r'^store(?P<pk>[0-9]+)/$', StoreDetailView.as_view(), name='store_detail'),
)
class StoreDetailView(DetailView):
model = Store
# the rest is django magic, you just have to provide the template
Is there any way to get a list of all views in an django app? I have googled for answer. All answers shows a way to get list of urls.
Getting list of all the views of a Django project:
To get all the views present in a Django project, we create a function get_all_view_names() which takes urlpatterns as input and returns the complete list of views being used in the project as the output.
First, we import the root_urlconf module using settings.ROOT_URLCONF. Then root_urlconf.urls.urlpatterns will give us the list of project's urlpatterns.
The above urlpatterns list contains RegexURLPattern and RegexURLResolver objects. Accessing .urlpatterns on a RegexURLResolver will further give us a list of RegexURLPattern and RegexURLResolver objects.
A RegexURLPattern object will give us the view name which we are interested in. The callback attribute on it contains the callable view. When we pass either a string in our urls like 'foo_app.views.view_name' representing the path to a module and a view function name, or a callable view, then callback attribute is set to this. Further accessing .func_name will give us the view name.
We call the function get_all_view_names() recursively and add the view names obtained from a RegexURLPattern object to a global list VIEW_NAMES.
from django.conf import settings
from django.core.urlresolvers import RegexURLResolver, RegexURLPattern
root_urlconf = __import__(settings.ROOT_URLCONF) # import root_urlconf module
all_urlpatterns = root_urlconf.urls.urlpatterns # project's urlpatterns
VIEW_NAMES = [] # maintain a global list
def get_all_view_names(urlpatterns):
global VIEW_NAMES
for pattern in urlpatterns:
if isinstance(pattern, RegexURLResolver):
get_all_view_names(pattern.url_patterns) # call this function recursively
elif isinstance(pattern, RegexURLPattern):
view_name = pattern.callback.func_name # get the view name
VIEW_NAMES.append(view_name) # add the view to the global list
return VIEW_NAMES
get_all_view_names(all_urlpatterns)
Getting list of all the views in a Django application:
To get the list of all the views present in a Django application, we will use the get_all_view_names() function defined above.
We will first import all the urlpatterns of the application and pass this list to the get_all_view_names() function.
from my_app.urls import urlpatterns as my_app_urlpatterns # import urlpatterns of the app
my_app_views = get_all_view_names(my_app_urlpatterns) # call the function with app's urlpatterns as the argument
my_app_views gives us the list of all the views present in my_app Django app.
Adding on to above fix by Rahul, if anyone is using Python3, you will need to use __name__ instead of func_name:
...
view_name = pattern.callback.__name__
...
otherwise you will get the following:
AttributeError: 'function' object has no attribute 'get_all_view_names'
(Thanks to scipy-gitbot at https://github.com/scipy/scipy/issues/2101#issuecomment-17027406
As an alternative, if you are disinclined to using global variables, here is what I ended up using :
all_urlpatterns = __import__(settings.ROOT_URLCONF).urls.urlpatterns
detail_views_list = []
def get_all_view_names(urlpatterns):
for pattern in urlpatterns:
if isinstance(pattern, RegexURLResolver):
get_all_view_names(pattern.url_patterns)
elif isinstance(pattern, RegexURLPattern):
detail_views_list.append(pattern.callback.__name__)
get_all_view_names(all_urlpatterns)
all_views_list = []
# remove redundant entries and specific ones we don't care about
for each in detail_views_list:
if each not in "serve add_view change_view changelist_view history_view delete_view RedirectView":
if each not in all_views_list:
all_views_list.append(each)
Then you can just iterate through all_views_list to get the list of filtered views.
update: Mar 1 2018
In Django 2.0, django.core.urlresolvers is moved to django.urls. RegexURLPattern and RegexURLResolver are renamed to URLPattern and URLResolver. So you should use
from django.urls import URLResolver, URLPattern
instead of
from django.core.urlresolvers import RegexURLResolver, RegexURLPattern
if you are using Django 2.
Get all Django and DRF views w/o using global vars
def get_all_views(urlpatterns, views=None):
views = views or {}
for pattern in urlpatterns:
if hasattr(pattern, 'url_patterns'):
get_all_views(pattern.url_patterns, views=views)
else:
if hasattr(pattern.callback, 'cls'):
view = pattern.callback.cls
elif hasattr(pattern.callback, 'view_class'):
view = pattern.callback.view_class
else:
view = pattern.callback
views[pattern.name] = view
return views