Unable to resolve URL string for path using name with reverse - python

I have been spending the better part of my week learning Django to build my website and I've stumbled upon an issue I can't seem to get working. I wish to resolve a URL string for a path by including with that path a particular name and then being able to reference that name down the line. This works fine until I change the route in path to use the include method.
First Attempt:
from django.url import include, path
from . import views
urlpatterns = [
path('testapp/', include('testapp.urls'), name='testapp'),
path('about/', views.about, name='about'),
]
Now when I call {% url 'about' %} from my template html file I get back '/about/' as expected but when I try and call {% url 'testapp' %} I get a NoReverseMatch exception instead of getting '/testapp/'. After digging through the documentation I stumbled upon this example that shows path with include using a namespace instead so I adapted the above a bit.
Second Attempt:
# from mysite/urls.py (adapted from before)
from django.url import include, path
from . import views
urlpatterns = [
path('testapp/', include('testapp.urls', namespace='testapp')),
path('about/', views.about, name='about'),
]
#from testapp/urls.py
from django.url import include, path
from . import views
app_name = 'testapp_name'
urlpatterns = [
path('', views.index, name='testapp_index'),
path('directory/', views.directory, name='testapp_directory'),
]
Now from the previous example I try using the namespace in lieu of a name {% url 'testapp' %} and I again get the same NoReverseMatch exception however using the namespace and name from my included url {% url 'testapp:directory' %} does work giving me '/testapp/directory/'.
I know there's some concept I'm not getting or something I'm overlooking but I'm just running around in circles at this point and would really appreciate any help somebody could afford me.
If it helps I'm trying to get the path so that I can use it in a navigation bar to highlight the currently activated tab. I'm also not hardcoding the paths as I'm trying to keep it DRY although at this point if I can't get it done I might have to but I'm hoping someone has a much better idea of what they're doing and could point me in a helpful direction. I appreciate all assistance and thank you!

The problem is that testapp is not a single view: it is an include(..), so it encapsulates a collection of views:
from django.url import include, path
from . import views
urlpatterns = [
path('testapp/', include('testapp.urls'), name='testapp'),
path('about/', views.about, name='about'),
]
It is not said that this collection contains a view at all, or it can contain multiple. Even if it only contains a single view, then it would be unsafe since you can later change your mind, and add an extra view.
If there are two or more views, then how will you decide what view (and therefore URL) to take? If the include(..) has two views: the "homepage" and the profile page, then this makes a significant difference.
You thus should refer to a real name, and whether you give the include(..) a namespace in the include(..) is irrelevant:
{% url 'testapp_name:testapp_index' %} <!-- first attempt -->
{% url 'testapp:testapp_index' %} <!-- second attempt -->
To reference the name of a real view.

{% url 'testapp_name:testapp_index' %}
or
{% url 'testapp_name:testapp_directory' %}
as you are using app_name in the urls file, you need to mention it with the name of the view

Related

What is the third argument for in Django url patterns?

I am new to Django and I am trying to understand it. If I write a url pattern like this
url(r'^$', 'newsletter.views.home', name='home'),
it works. and If I write it like this
url(r'^$', 'newsletter.views.home'),
it still works, but I get the following data from the server
RemovedInDjango110Warning: Support for string view arguments to url() is deprecated and will be removed in Django 1.10 (got newsletter.views.contact). Pass the callable instead.
url(r'^contact/$', 'newsletter.views.contact'),
My first question is what does the third argument do. the
name='home' or name='contact'. What is it reffering to.
and my second question is what does
Pass the callable instead.
mean? Again, I have read the docs and came here for a bit more clarity in laymen's terms. All help and advice is welcome
When it says pass the callable, it means you should import the view itself and include that in your url pattern.
from newsletter.views import home
url(r'^$', home, name='home'),
Another option is to import the views module itself
# renaming allows us to import more than one views at once
from newsletter import views as newsletter_views
url(r'^$', newsletter_views.home, name='home'),
Naming url patterns allows you to reverse url patterns (e.g. go from a name to a url). This means you don't have to hardcode urls in your views and templates.
If you have
url(r'^home/$', home, name='home'),
then you can use reverse('home') in your code, and {% url 'home' %} in your templates, instead of writing /home/ repeatedly.

Django URL names use in Templates

Right now in my templates I hardcore the links in my navigation like the following:
`base.html`
About
Contact
<!-- etc -->
In my urls.py
urlpatterns = patterns('',
url(r'^about/$', TemplateView.as_view(template_name='pages/about.html'), name='about'),
url(r'^contact/$', TemplateView.as_view(template_name='pages/contact.html'), name='contact'),
)
Is there a way that in my base.html file reference the urlpatterns from urls.py so that anytime I change those, it reflects everywhere across my pages and templates?? Something like
<!-- what I would like to do -->
About
About
This is why url tag was invented:
Returns an absolute path reference (a URL without the domain name)
matching a given view function and optional parameters.
If you’re
using named URL patterns, you can refer to the name of the pattern in
the url tag instead of using the path to the view.
This basically means that you can use url names configured in the urlpatterns in the url tag:
About
Contact
This gives you more flexibility. Now any time the actual url of about or contact page changes, templates would "catch up" the change automagically.
Use Django's url template tag (docs here) with your named url pattern.
Example:
About
Contact
Note that the name you put in ' ' will be the name of the particular url pattern in your urls.py. Also, if this is the urls.py file in an app (that is, it gets routed initially from the base urls.py), you'll need to include the namespacing of the app.

How to change the url in urls.py? (Django app)

I'm trying to change the url of http://localhost:8000/stories-and-literature/fairy-tales/ to http://localhost:8000/stories-and-literature/classic-literature/, and I'm not to sure how I can change it in my urls.py. So far, I have this code in urls.py:
from django.conf.urls import patterns, url
from topictree import views
urlpatterns = patterns('',
(r'^$', 'topictree.views.index'),
(r'^(?P<slug>\D+)/$', 'topictree.views.tree')
)
I want to change the slug of url from "fairy-tales" to "classic-literature" because I want to present the url like a tree. In this case, both "fairy-tales" and "classic-literature" are children of "story-and-literature", so when I click on the "fairy-tales" link and then click on the "classic-literature" link, the "fairy-tales" slug should be removed, and be replaced by the "classic-literature" slug.
I was thinking of changing the url in views.py instead of urls.py since views.py contains the control flow of the program. Is it possible to change the url in views.py instead of urls.py?
Any help would be much appreciated.
Foo Bar User's link is a good place to start but judging by your question I would say you should go straight to the Django Docs
https://docs.djangoproject.com/en/1.6/topics/http/urls/
That should get you back on your feet. :)

how to use the href attribute in django templates

When I try to use a link in my Django template from /appname/index/ to get to /appname/detail/### I am instead getting to /appname/index/detail/### which is not what I'm trying to get so my app can't find it in the urlconf of course.
First the urls.py line for the detail page
url(r'detail/(?P<jobID>\d+)/$', 'appname.views.detail')
Additionally, the root urlconf
urlpatterns = patterns('',
url(r'^appname/', include('appname.urls')),
url(r'^admin/', include(admin.site.urls)),
)
Next the template code trying to get there
{% for job in jobList %}
{{ job.name }}
I'm not sure what else might be applicable information, just ask if you would like to see something else. I also tried :
{{ job.name }}
But that didn't work either. Thank you in advance for any help.
Add / at start in href:
{{ job.name }}
And for the url tag to work you need to do it like this:
{{ job.name }}
From my experience, as long as you have defined the url of the page the href tag should lead to in urls.py, include the absolute path in the format below.
Site name: yyyy.com
Url of page to redirect to in urls.py: yyyy.com/signup/
Sample link: Signup
You will notice that what goes inside the href tag is sort of appended to the current url. For more dynamic links, you can use some python as of DTL guidelines.
Suppose u are at
myapp/detail
and u want to go at page
myapp/anything
U shoud do this
Page
For django templates
Url.py File
app_name = 'app_name'
path('url/', TestView.as_view(), name='the_url'),
path('url//<int:id>', TestView.as_view(), name='the_url'),
templates(html.py)
Test
Test
I got the same problem, new address is being added after the "/" URL which is not recognised.
Can be solved by adding "/" at the address you are giving at the href attribute.
ex: href:services is wrong
href:/services is to be used to go to services page.

Cannot Get Haystack Tutorial Working

I have completed the tutorial for Haystack w/ Whoosh and re-read it about 6 times in the past few hours and cannot seem to figure out what my issue is. Basically, everything seemed to installed correctly, however when I visit the /search URL all I see is my base template without the search template (no input box/header/etc). This is my urls.py at the application level:
urlpatterns = patterns('',
url(r'^$', views.index, name='index'),
url(r'^search/', include('haystack.urls')),
url(r'a/list/$', views.admin_list, name='admin_list'),
url(r'a/list/(?P<list_id>\d+)/edit/$', views.admin_edit, name='admin_edit'),
)
The template lives in myapp/templates/search/search.html. I have added nothing to my views.py, because the tutorial didn't go over adding anything to that file. What am I missing here?
What is content of the data template file ( appname_text) file , if you are keeping document =true in search_index.py file your data template should have the fields that are to be searched .
data template for will be something like.
{{ object.foo }}
{{ object.bar }}

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