The linkcolumn about django-tables2 - django

I use django-tables2 to show some data in page,and now I want to make the cell link to some url,but the link url such as :
url(r'^(?P\w+)/(?P\d+)/$', 'pool.views.pooldatestock',
name="pool_date_stock"),
and I read the documents of django-tables2,but I can't find some excample about this problem.
the tables show in the page's url just like:http://127.0.0.1:8000/pool/20111222/
I try to write this in my tables.py :
class PoolTable(tables.Table):
number = tables.LinkColumn('pool.views.pooldatestock', args=[A('number')])
date = tables.Column()
and then I try to write:
class PoolTable(tables.Table):
number=tables.LinkColumn('pool.views.pooldatestock',
args=[A('date')],
kwargs=A('number')])
date = tables.Column()
but it's error too...
somebody can tell me how to solve this problem?or should I create my own table view, without django-tables.
Thanks.and Merry Christmas:)

It makes no sense for the kwargs parameter to be given a list, it should be given a dict. However as your URL doesn't used named groups, it doesn't need keyword arguments anyway. Just put both URL parameters in the args parameter:
class PoolTable(tables.Table):
number = tables.LinkColumn('pool.views.pooldatestock',
args=[A('date'), A('number')])
date = tables.Column()

Related

Why do I get an unexpected keyword argument?

I have created a model in my Djano project and the name of the model is Questions in which I have created a primary key called questionid. I am able to get all listings as summaries on one page however when I try to get a detailed listing of one query (say question number 4 out of the several in the table) by going to the http://127.0.0.1:8000/qanda/4 (here 4 is the question number), I get an error that says
TypeError at /qanda/4
question() got an unexpected keyword argument 'question_questionid'
Please see the code below
In my model's views file
def question(request):
questionsm = Questions.objects.order_by('-published_date').filter(is_published=True)
context = {
'questionid': questionsm
}
return render(request,'qanda/question.html', context)
In my model url file
path('<int:question_questionid>', views.question, name='question'),
I will appreciate any help. thanks
You are not passing the var to the view.
def question(request, **id_what_you_want**):
# and if you want an individual view, you should get by id
Questions.objects.get(pk=id_what_you_want)

Related posts by tag name

i want to show related posts by tag name However i got the error " get() returned more than one Tag -- it returned 2!"
def post_detail(request,slug):
post=get_object_or_404(Post,slug=slug)
comments=Comment.objects.filter(post=post,reply=None,statusc=2).order_by('-date')
comment_count=len(Comment.objects.filter(post=post, statusc=2))
tag=get_object_or_404(Tag,post=post)
related_item=Post.objects.filter(tag__tag_name__icontains=tag.tag_name,status=2).order_by('-created_date').distinct()[:3]
You can just query like:
def post_detail(request,slug):
post=get_object_or_404(Post,slug=slug)
comments=Comment.objects.filter(post=post,reply=None,statusc=2).order_by('-date')
comment_count=len(comments)
related_items = Post.objects.filter(
tag__post=post
).order_by('-created_date').distinct()[:3]
# ...
Or if you want to exclude the current post:
def post_detail(request,slug):
post=get_object_or_404(Post,slug=slug)
comments=Comment.objects.filter(post=post,reply=None,statusc=2).order_by('-date')
comment_count=len(comments)
related_items = Post.objects.exclude(pk=post.pk).filter(
tag__post=pos
).order_by('-created_date').distinct()[:3]
# ...
It is also better to perform a len(..) on the comments, since that will result in making a query to fetch the comments, whereas using two separate queries, will hit the database twice.
As per documentation, get() is used for retrieving 1 item. If there are multiple items, here there could be multiple tags used in single Post, it will throw error.
So, you can change it like this:
tags=Tag.objects.filter(post=post)
related_item=Post.objects.filter(tag__in=tags,status=2).order_by('-created_date').distinct()[:3]

Django: How to use django.forms.ModelChoiceField with a Raw SQL query?

I'm trying to render a form with a combo that shows related entities. Therefore I'm using a ModelChoiceField.
This approach works well, until I needed to limit which entities to show. If I use a simple query expression it also works well, but things break if I use a raw SQL query.
So my code that works, sets the queryset to a filter expression.
class ReservationForm(forms.Form):
location_time_slot = ModelChoiceField(queryset=LocationTimeSlot.objects.all(), empty_label="Select your prefered time")
def __init__(self,*args,**kwargs):
city_id = kwargs.pop("city_id") # client is the parameter passed from views.py
super(ReservationForm, self).__init__(*args,**kwargs)
# TODO: move this to a manager
self.fields['location_time_slot'].queryset = LocationTimeSlot.objects.filter(city__id = city_id )
BUT, if I change that to a raw query I start having problems. Code that does not work:
class ReservationForm(forms.Form):
location_time_slot = ModelChoiceField(queryset=LocationTimeSlot.objects.all(), empty_label="Select your prefered time")
def __init__(self,*args,**kwargs):
city_id = kwargs.pop("city_id") # client is the parameter passed from views.py
super(ReservationForm, self).__init__(*args,**kwargs)
# TODO: move this to a manager
query = """SELECT ts.id, ts.datetime_to, ts.datetime_from, ts.available_reserves, l.name, l.'order'
FROM reservations_locationtimeslot AS ts
INNER JOIN reservations_location AS l ON l.id = ts.location_id
WHERE l.city_id = %s
AND ts.available_reserves > 0
AND ts.datetime_from > datetime() """
time_slots = LocationTimeSlot.objects.raw(query, [city_id])
self.fields['location_time_slot'].queryset = time_slots
The first error I get when trying to render the widget is: 'RawQuerySet' object has no attribute 'all'
I could solve that one thanks to one of the commets in enter link description here, by doing:
time_slots.all = time_slots.__iter__ # Dummy fix to allow default form rendering with raw SQL
But now I'm getting something similar when posting the form:
'RawQuerySet' object has no attribute 'get'
Is there a proper way to prepare a RawQuerySet to be used by ModelChoiceField?
Thanks!
Are you sure you actually need a raw query there? Just looking at that query, I can't see any reason you can't just do it with filter(location__city=city_id, available_reserves__gte=0, datetime_from__gt=datetime.datetime.now()).
Raw query sets are missing a number of methods that are defined on conventional query sets, so just dropping them in place isn't likely to work without writing your own definitions for all those methods.
I temporarily fixed the problem adding the missing methods.
The way I'm currently using the ModelChoiceField I only needed to add the all() and get() methods, but in different scenarios you might need to add some other methods as well. Also this is not a perfect solution because:
1) Defining the get method this way migth produce incorrect results. I think the get() method is used to validate that the selected option is within the options returned by all(). The way I temporarily implemented it only validates that the id exists in the table.
2) I guess the get method is less performant specified this way.
If anyone can think of a better solution, please let me know.
So my temporary solution:
class LocationTimeSlotManager(models.Manager):
def availableSlots(self, city_id):
query = """SELECT ts.id, ts.datetime_to, ts.datetime_from, ts.available_reserves, l.name, l.'order'
FROM reservations_locationtimeslot AS ts
.....
.....
MORE SQL """
time_slots = LocationTimeSlot.objects.raw(query, [city_id])
# Dummy fix to allow default form rendering with raw SQL
time_slots.all = time_slots.__iter__
time_slots.get = LocationTimeSlot.objects.get
return time_slots

Sharing data between two views through template in Django?

I may have overcomplicated things.
I have two views. The first view generates a bunch of temporary data based on the user's input from the form. Each of the generated data contains a name and misc data. I want to pass only the names to the template to be rendered as a list of hyperlinks. If the user clicks on one of them, the second view should be given the specific name the user clicked on so that the view can manipulate it. The only problem is, I don't know how to get the misc data associated with the name.
The misc data generated could contain random characters that's not a standard character in URLs, so I can't turn misc into a hyperlink like I can with just the name.
I have something like this:
views:
# Displays the temp data names
def display(request):
return render_to_response('display.html',{},context_instance=RequestContext(request))
# User provides input, generate temp data to be displayed as hyperlinks
def search(request):
form = SearchForm(request.POST)
if form.is_valid():
usr_input = form.cleaned_data['input']
data = generate_data(usr_input) # generates a list of (name, misc) data.
request.session['hyperlinks'] = get_list_names(data) # returns only names in data
return HttpResponseRedirect('views.display')
else:
....
# User has clicked on a hyperlink, we must process specific data given its name.
def process_data(request, name):
# How to get associated misc data created from search()?
I haven't written the template yet, but the idea is:
template:
{% for name_link in request.session.hyperlinks %}
<a href={% url process name_link %}>
{% endfor %}
One solution could be creating a bunch of session variables:
for name in get_list_names(data):
request.session[name] = // associated misc data
But this seems like a waste. Plus I'd have to manage deleting the session variable later on since this is only temporary data generated based on user input. A new input from the user would create another huge horde of session variables!
Another solution could be to store it temporarily in the database, but that also seems like a bad idea.
EDIT - Trying out suggestion by christophe31:
I'm not quite sure if I understand your suggestion, but is it something like this?
data_dict = {name1:misc1, name2:misc2, etc...}
encoded = urllib.urlencode(data_dict) # encoded = 'name1=misc1&name2:misc2...etc'
request.session['hyperlinks'] = encoded
A few questions on this though:
1) Wouldn't encoding it using urllib defeat the purpose of having a dictionary? It returns a string rather than a dictionary
2) To expand on (1), what if the misc data had '&' and '=' in it? It would screw up parsing which is the key and value by the second view. Also, misc data may have unusual characters, so allowing that to be part of the url to be displayed may be bad.
3) Does Django protect from allowing the user to maliciously modify the session misc data so that the misc data generated from the first view may be different than the one passed to the second view? That would be a problem!
You may want to put a dictionary as a session variable, set a cookie, or pass as get argument throught the link your data.
For me you have to put all these data in a dictionary before export it as get parameters (with urllib2) or store it in your user's session.
Ask me if you want more info on a suggested way.
Edit:
They are 2 ways I see, by session:
data_dict = {name1:misc1, name2:misc2, etc...}
request.session['hyperlinks'] = data_dict
Or passing to the template the data if no session backend:
data_dict = {name1:misc1, name2:misc2, etc...}
encoded = urllib.urlencode(data_dict)
return render(request, "my_template.html", {"url_params":encoded,}
and
Go to results

Assigning values to a query result already set up with a foreign key

I have a database of exhibition listings related by foreign key to a database of venues where they take place. Django templates access the venue information in the query results through listing.venue.name, listing.venue.url, and so on.
However, some exhibitions take place in temporary venues, and that information is stored in the same database, in what would be listing.temp_venue_url and such. Because it seems wasteful and sad to put conditionals all over the templates, I want to move the info for temporary venues to where the templates are expecting info for regular venues. This didn't work:
def transfer_temp_values(listings):
for listing in listings:
if listing.temp_venue:
listing.venue = Venue
listing.venue.name = listing.temp_venue
listing.venue.url = listing.temp_venue_url
listing.venue.state = listing.temp_venue_state
listing.venue.location = listing.temp_venue_location
The error surprised me:
ValueError at /[...]/
Cannot assign "<class 'myproject.gsa.models.Venue'>": "Exhibition.venue" must be a "Venue" instance.
I rather thought it was. How do I go about accomplishing this?
The error message is because you have assigned the class Venue to the listing, rather than an instance of it. You need to call the class to get an instance:
listing.venue = Venue()