How to recognize urls with get parameters un django? - django

I am learning Django, usually I use urls like www.mysite.com/post/1, and I have understood them because they are well described in the documentation.
Now I need to create a url like: www.mysite.com/calendar/?day=21&?month=12&year=2020, I don't understand what should I write in my ulrpatterns list.
I have tried something like this:
url(r'^search/(?P<parameter>\w+)', views.calendar, name='calendar')
but it doesn't work.
What should I write as regex expression?
Thanks

These parameters are not part of the path, you can't capture them using the url patterns.
You can access them directly inside your view by using request.GET, see the docs.
A common pattern is the following:
def calendar(request):
day = request.GET.get("day") # Will be None if "day" isn't in the query
month = request.GET.get("month")
year = request.GET.get("year")
[...]

Related

How to use variable at start of django url to return to view?

I am trying to pass the first part of a django url to a view, so I can filter my results by the term in the url.
Looking at the documentation, it seems quite straightforward.
However, I have the following urls.py
url('<colcat>/collection/(?P<name>[\w\-]+)$', views.collection_detail, name='collection_detail'),
url('<colcat>/', views.collection_view, name='collection_view'),
In this case, I want to be able to go to /living and have living be passed to my view so that I can use it to filter by.
When trying this however, no matter what url I put it isn't being matched, and I get an error saying the address I put in could not be matched to any urls.
What am I missing?
<colcat> is not a valid regex. You need to use the same format as you have for name.
url('(?P<colcat>[\w\-]+)/collection/(?P<name>[\w\-]+)$', views.collection_detail, name='collection_detail'),
url('(?P<colcat>[\w\-]+)/$', views.collection_view, name='collection_view'),
Alternatively, use the new path form which will be much simpler:
path('<str:colcat>/collection/<str:name>', views.collection_detail, name='collection_detail'),
path('<str:colcat>/', views.collection_view, name='collection_view'),

how to create params in django url?

I have a django project where url is like this
url(r'^invoice/(?P<invoice_id>[A-Za-z0-9]+)/(?P<order_id>[A-Za-z0-9]+)$',GenerateInvoicePdf,name='invoice'),
which generates url localhost:8000/invoice/2341wq23fewfe1231/3242
but i want url to be like localhost:8000/invoice?invoice_id=2341wq23fewfe1231&order_id=3242
i tried documentation and used syntax like this re_path(r'^comments/(?:page-(?P<page_number>\d+)/)?$', comments), But did not get desired result.
how can i do so?
The parts which you are trying to write after ? is called url query string. You don't need to define them in the urls.py. You can just use:
re_path(r'^comments/$', comments),
And inside comments views, you can access the query string like this:
def comments(request):
invoice_id = request.GET.get('invoice_id')
order_id = request.GET.get('order_id')
# rest of the code

Generate url for Django Simple History historical object

Given an model called Stuff, I want the url to a HistoricalStuff object.
In other words, how does one implement get_historical_url in the below code snippet?
stuff = Stuff.objects.first()
stuff.pk
-> 100
historical_stuff = stuff.history.first() # we want to get url for this
historical_stuff.pk
-> 1
get_historical_url(historical_stuff)
-> /path/to/admin/stuff/100/history/1
Obviously the dumb solution would be to use a format string but I'd rather use urlresolvers
After much digging around, I found in the simple history source code that the url name is similar to the admin change names, namely admin_%s_%s_simple_history.
With this knowledge, get_historical_url looks like
def get_simplehistory_url(history_obj):
parent_obj = history_obj.history_object
return urlresolvers.reverse('admin:{}_{}_simple_history'.format(
parent_obj._meta.app_label, parent_obj._meta.model_name), args=(parent_obj.id, history_obj.pk))

Ignore params in urls

I need to bolt a quick city-specific thing onto a site I am currently building. I am going to do it something like this - http://example.com/XX/normal-slug. What I have set up in my urls.py is this:
url(r'^(?P<city>[a-zA-Z]{2})/', include('homepage.urls', namespace='homepage')),
url(r'^(?P<city>[a-zA-Z]{2})/section/', include('section.urls', namespace='section')),
# etc
The problem I am encountering now is that all of a sudden my methods all are now expecting a "city=XX" param. I plan to process the actual city business logic in a middleware. My question is... is there anyway have django "ignore" the named param? I don't want to modify all my views now to take either **kwards or 'city' param. If I hard code the city code, it does what I expect:
url(r'^XX/section/', include('section.urls', namespace='section')),
So can I replicate that behaviour, but dynamically?
(Also, I plan on something more robust further down the line, probably Django Sites)
You can use a non-capturing regex to accept the parameter but not pass it to the views.
r'^[a-zA-Z]{2}/section'
Set the param as optional in the regexp with ?:
url(r'^((?P<city>[a-zA-Z]{2})/)?section/', include('section.urls', namespace='section')),
If city is not sent in the URL, your view will receive city=None

How to use query results in url regex in Django

I want to use a database query to generate my URL configuration. Something like:
states = State.objects.all().values_list('pk', flat=True)
And then a regex like:
(r'^state/(?P<state>' + '|'.join(states) + ')/$'
The idea is that I can have URLs like:
/state/ca/
/state/az/
Etc.
The problem is that when I do syncdb, the query above fails, throwing a DatabaseError.
Is there a good way to do this? I've tried the obvious change, which would be:
try:
states = State.objects.all().values_list('pk', flat=True)
except DatabaseError:
# First sync, use dummy data
states = []
But this doesn't work because the exception is thrown at the regex, not at the query definition.
Ideas?
Why do you need to constrain this in the URL pattern itself? Much better to accept all two-letter codes, and check in the view.
(r'^state/(?P<state_code>\w{2})/$'
def view_state(request, state_code):
state = get_object_or_404(State, pk=state_code)