passing object data through URL - django

I know that I can pass object values through a URL pattern and use them in view functions. For instance:
(r'^edit/(?P<id>\w+)/', edit_entry),
can be utilized like:
def edit_entry(request, id):
if request.method == 'POST':
a=Entry.objects.get(pk=id)
form = EntryForm(request.POST, instance=a)
if form.is_valid():
form.save()
return HttpResponseRedirect('/contact/display/%s/' % id)
else:
a=Entry.objects.get(pk=id)
form = EntryForm(instance=a)
return render_to_response('edit_contact.html', {'form': form})
But how do I pass a value from a model field (other than "id") in the url? For instance, I have an abstract base model with a field "job_number" that is shared by child models "OrderForm" and "SpecReport". I want to click on the "job_number" on the order form and call the Spec Report for that same job number. I can create an
href="/../specifications/{{ record.job_number }}
to pass the info to the url, but I already know that this regex syntax is incorrect:
(r'^specifications/(?P<**job_number**>\w+)/', display_specs),
nor can I capture the job_number in the view the same way I could an id:
def display_specs(request, job_number):
records = SpecReport.objects.filter(pk=job_number)
tpl = 'display.html'
return render_to_response(tpl, {'records': records })
Is there an easy approach to this or is it more complicated than I think it is?
the amended code is as follows:
(r'^specdisplay/?agencyID=12/', display_specs),
and:
def display_specs(request, agencyID):
agencyID= request.GET.get('agencyID')
records = ProductionSpecs.objects.filter(pk=id)
tpl = 'display_specs.html'
return render_to_response(tpl, {'records': records })
not sure how to filter. pk is no longer applicable.

Yes, you are making this a little more complicated that it is.
In your urls.py you have:
(r'^edit/(?P<id>\w+)/', edit_entry),
Now you just need to add the almost identical expression for display_specs:
(r'^specifications/(?P<job_number>\w+)/', display_specs),
Parenthesis in the regex identifies a group and the (?P<name>...) defines a named group which will be named name. This name is the parameter to your view.
Thus, your view will now look like:
def display_specs(request, job_number):
...
Finally, even though this will work, when you redirect to the view, instead of using:
HttpResponseRedirect('/path/to/view/%s/' % job_number)
Use the more DRY:
HttpResponseRedirect(
reverse('display_specs', kwargs={'job_number': a.job_number}))
Now if you decide to change your resource paths your redirect won't break.
For this to work you need to start using named urls in your urlconf like this:
url(r'^specifications/(?P<job_number>\w+)/', display_specs, name='display_specs'),

Not knowing what your model structure is like ... why couldn't you just pass the particular job's id and then pick it up with a query?
Afaik every model automatically has an id field that autoincrements and is a unique identifier of a row (an index if you will), so just change the href creation to {{record.id}} and go from there.
Try passing the job_number through the url then, especially if you don't care about pretty url's too much just do this:
url: /foo/bar/?job_number=12
no special markup to catch this btw, the regex is r'^foo/bar/'
And then read it in the view like this:
job_number= request.GET.get('job_number')

I really don't understand your question. What's the difference between passing id and passing job_number in a URL? If you can do one, why can't you do the other? And once the job_number is in the view, why can't you do a normal filter:
records = SpecReport.objects.filter(job_number=job_number)

Related

Django object "lock" and context rendering

I have a simple(I think) question, about Django context rendering.
I'll step right into it -
Basically what I need is, some temp table, which in my case, I called Locked. And when a user presses a button, which Is a form, that object goes straight to the table Locked(just a simple insert). And inside that table there is a field called is_locked, and if its True, that object needs to go gray, or to have some lock icon inside the html table.
Just some kind of a viewable sign, that an object is inside the table Locked, and that another user can't access it.
But, my problem is, since in my views.py, my lock function is not returning exact html where I want to render that locker icon, instead, it returns another html.
Is there any way, to render same context, on 2 html pages? Thank's.
This is my code :
views.py
def lock(request, pk):
# Linking by pk.
opp = get_object_or_404(OpportunityList, pk=pk)
opp_locked = get_object_or_404(Locked, pk=pk)
# Taking two parametters for 2 fields.
eluid = Elementiur.objects.get(eluid=pk)
user = User.objects.get(username=request.user)
# Dont bother with this one! Just pulling one field value.
field_name = 'optika_korisnik'
obj = OpportunityList.objects.get(pk=pk)
field_object = OpportunityList._meta.get_field(field_name)
field_value = getattr(obj, field_object.attname)
# This is the main part! This is where i'm inserting data into Locked table.
if opp_locked.DoesNotExist:
opp_locked.id = int(eluid.eluid)
opp_locked.locked_eluid = eluid
opp_locked.locked_comment = field_value
opp_locked.locked_user = user
opp_locked.locked_name = 'Zaključao korisnik - ' + request.user.username
opp_locked.is_locked = True
opp_locked.save()
# This is what has to be returned, but i need context on the other page.
return render(request, 'opportunity/detalji/poziv.html',
{'opp': opp, 'locked': opp_locked})
else:
# This return has the context that i need(from the first opp_locked variable)
return render(request, 'opportunity/opp_optika.html', {'locked_test': opp_locked})
I can provide more code, but i think that it's not important for this type of question, because all of the logic is happening inside the lock finction, and last two returns.
I just had a quick overview of your snippet sorry if this not help you but you need to review it a little bit.
You call DoesNotExist on an instance of a Locked model
if opp_locked.DoesNotExist: [...]
that's not how you should use this exception.
You have a method .exists() that is available but only for Querysets.
Also if your instance does not exists you are alredy returning an Http404 response when you use get_object_or_404() method.
And perhaps you should avoid sharing primary keys between instances and replace them with models.OneToOneField (OneToOnefield)
Since i got no answers, i added a new field, is_locked, into my Locked model and that solved it.

Django URLs: Can't get the keyword arg into my view?

The URL pattern having issues is:
url(r'^$', business_list, name='business_list_home'),
url(r'^(?P<param>\w+)$', business_list, name='business_list_results'),
My view is:
#render_to('app/business_list.html')
def business_list(request, param=None):
queryset = Business.objects.all()
search_form = SearchForm
print request.GET
if param in request.GET:
param = request.GET.get('param')
if queryset.filter(city__iexact=param).exists():
queryset = queryset.filter(city__iexact=param)
elif queryset.filter(category__iexact=param).exists():
queryset = queryset.filter(category__iexact=param)
print queryset
else:
queryset = None
print queryset
return {'business_list': queryset, 'search_form': search_form}
Essentially, I don't understand why when I go to /Miami I don't have access to it via request.GET['param'] in the view? print request.GET prints <QueryDict: {}>
The reason I want to do this is to have a nice URL scheme for displaying results of businesses for the city or category (and that's why I check if it's a city or category in the view too) in the url. Let me know if there's a better way to accomplish this like
url(r'^$', business_list),
url(r'^(?P<city>\w+)$', business_list),
url(r'^(?P<category>\w+)$', business_list),
url(r'^(?P<category>\w+)/(?P<city>\w+)$', business_list),
Thanks for any help!
business_list is a function that takes a request and a parameter called "param" (should probably give it a better name as to make it a little less generic). In Django, the URL routes can define what values get passed to the parameters of the view functions.
In the situation above, when a user goes to /Miami, Django will try to match the string "Miami" with any of the regular expressions defined in the URL routes. In this case, the matching expression is ^(?P<param>\w+)$. When this match is made, the string Miami is captured into param.
Django will then call business_list(request, param="Miami"). Note that there were no query parameters passed in the URL (e.g., /Miami?color=blue).
The issue in the code you've written above is that you're checking to see not if param exists, but rather that param was passed in the query parameters. Try going to the URL /Miami?param=test and it'll probably work the way that you expected.
The real fix here is to not reference request.GET, because using GET parameters is exactly what you're trying to avoid. So, instead of
if param in request.GET:
param = request.GET.get('param')
if queryset.filter(city__iexact=param).exists():
queryset = queryset.filter(city__iexact=param)
elif queryset.filter(category__iexact=param).exists():
queryset = queryset.filter(category__iexact=param)
print queryset
Just do:
if param:
if queryset.filter(city__iexact=param).exists():
queryset = queryset.filter(city__iexact=param)
elif queryset.filter(category__iexact=param).exists():
queryset = queryset.filter(category__iexact=param)

django - how can I clean variable data passed by an url?

When I'm using a form I clean field data using Django forms but how do you clean variable data that's passed by an URL?
For example I have an URL like this: http://mywebsite.com/tags/my-tag/ where my-tag is the variable that I'm passing to a function on my views.py.
I tried to use a Django form to clean the data but I'm getting en error saying "'TagForm' object has no attribute 'cleaned_data'".
I know my-form variable is reaching the tags function in the views.py since I'm able to show its content on a template so the problem is probably with the way I'm using the form.
views.py
def tags(request, my-tag):
tagform = TagForm(request.GET)
cleaned_dt = tagform.cleaned_data
form_tag = cleaned_dt['tag']
forms.py
class TagForm(forms.Form):
tag = forms.CharField()
Any ideas?
The cleaned_data dictionary attribute appears after you call is_valid method on your form.
def tags(request, my-tag):
tagform = TagForm(request.GET)
if tagform.is_valid():
cleaned_dt = tagform.cleaned_data
form_tag = cleaned_dt['tag']
return render(request, "may_template.html", {"form":tagform})
You are creating a TagForm with a request object, but you're not giving the TagForm the value of my-tag anywhere that I can see.
The /my-tag/ section of the URL isn't a request parameter. It's part of the url, and presumably passed to the view function as my-tag (you might want to rename it my_tag to be more Pythonic).
Edit
You can simple create a dict object to initialize to Form object instead of request.GET. An example is here.
data = {'tag': my_tag,
'anotherIfNecessary': 'Hi there'}
tagform = TagForm(data)
Basically, the dictionary used to populate a form object must contain a mapping of form field names to the value you wish to set it at.
In this case, you have a form field name of "tag" and want to set it to my-tag (are you sure you don't get a syntax error with the dash in the variable name? I do...). I've corrected my example.

Help understanding a Django view

I am trying to follow the code listed on https://github.com/alex/django-ajax-validation/blob/master/ajax_validation/views.py
I have been able to understand a small chunk of it. I have added comments stating my understanding of what is happening.
I would really appreciate some assistance on questions I listed in comments next to the lines I couldn't quite follow.
def validate(request, *args, **kwargs):
# I thing it is some sort of initializations but I cannot really understand what's happening
form_class = kwargs.pop('form_class')
defaults = {
'data': request.POST
}
extra_args_func = kwargs.pop('callback', lambda request, *args, **kwargs: {})
kwargs = extra_args_func(request, *args, **kwargs)
defaults.update(kwargs)
form = form_class(**defaults)
if form.is_valid(): #straightforward, if there is no error then the form is valid
data = {
'valid': True,
}
else:
# if we're dealing with a FormSet then walk over .forms to populate errors and formfields
if isinstance(form, BaseFormSet): #I cannot really understand what is BaseFromSet
errors = {}
formfields = {}
for f in form.forms: # I am guessing that this is for when there are multiple form submitted for validation
for field in f.fields.keys(): # I think he is looping over all fields and checking for error. what does add_prefix () return? and what is formfields[]?
formfields[f.add_prefix(field)] = f[field]
for field, error in f.errors.iteritems():
errors[f.add_prefix(field)] = error
if form.non_form_errors():
errors['__all__'] = form.non_form_errors() # what is the '__all__'?
else:
errors = form.errors
formfields = dict([(fieldname, form[fieldname]) for fieldname in form.fields.keys()])
# if fields have been specified then restrict the error list
if request.POST.getlist('fields'): # I am having a hard time understanding what this if statement does.
fields = request.POST.getlist('fields') + ['__all__']
errors = dict([(key, val) for key, val in errors.iteritems() if key in fields])
final_errors = {} # here the author of this code totally lost me.
for key, val in errors.iteritems():
if '__all__' in key:
final_errors[key] = val
elif not isinstance(formfields[key].field, forms.FileField):
html_id = formfields[key].field.widget.attrs.get('id') or formfields[key].auto_id
html_id = formfields[key].field.widget.id_for_label(html_id)
final_errors[html_id] = val
data = {
'valid': False or not final_errors,
'errors': final_errors,
}
json_serializer = LazyEncoder() # Why does the result have to be returned in json?
return HttpResponse(json_serializer.encode(data), mimetype='application/json')
validate = require_POST(validate) # a decorator that requires a post to submit
LazyEncoder
class LazyEncoder(JSONEncoder):
def default(self, obj):
if isinstance(obj, Promise):
return force_unicode(obj)
return obj
form_class = kwargs.pop('form_class')
This is simply pulling the keyword argument, form_class, that was passed in via the URL conf.
(r'^SOME/URL/$', 'ajax_validation.views.validate',
{'form_class': ContactForm}, # this keyword argument.
'contact_form_validate')
BaseFormSet is simply the formset class doing the work behind the scenes. When you don't know, search the source! grep -ri "baseformset" . It's an invaluable tool.
Take a look at at django.forms.formsets to see how formset_factory produces new "formset" classes based on the BaseFormSet, hence the factory part!
I am guessing that this is for when there are multiple form submitted for validation
Yes, that's exactly what a formset is for (dealing with multiple forms)
I think he is looping over all fields and checking for error. what does add_prefix () return? and what is formfields[]?
Yes, that would be looping through the field names.
add_prefix() is for prefixing form field names with a specific form. Because a formset repeats form elements multiple times, each field needs a unique prefix, such as 0-field1, 1-field1, etc.
formfields is just an empty dictionary defined a few lines above.
what is the 'all'?
__all__ is defined at the top of django.forms.forms
NON_FIELD_ERRORS = '__all__'
It's just what non field specific errors (such as constraints across 2 fields) are stored under in the errors dictionary as opposed to errors[fieldname].
I am having a hard time understanding what this if statement does.
The author has left a note:
# if fields have been specified then restrict the error list
if request.POST.getlist('fields'):
It's checking if you specified any specific fields to validate in your URLConf, this is not django but ajax_validation.
You can see that he's overwriting his errors dictionary based on only the fields specified, thus passing on the validation only for those fields.
errors = dict([(key, val) for key, val in errors.iteritems() if key in fields])
here the author of this code totally lost me.
The author has mapped a custom errors and fields dictionary to specific field names with prefixes, (as opposed to the usual FormSet with each form having its own errors dictionary, unaware of the formset itself) which he presumably uses in the AJAX response to validate all fields.
Normally, you can iterate over a formset and go through the errors on a form by form basis, but not so if you need to validate all of them through ajax.
The line pulling html_id should be straight forward most of the time, but it's there because form widgets CAN add interesting things to the end of the ID's based on whether or not the widget is a radio select for example.
From source comments :
# RadioSelect is represented by multiple <input type="radio"> fields,
# each of which has a distinct ID. The IDs are made distinct by a "_X"
# suffix, where X is the zero-based index of the radio field. Thus,
# the label for a RadioSelect should reference the first one ('_0').
Why does the result have to be returned in json?
Because it's an ajax request and javascript easily eats json.
2- could you go through these lines of code...
extra_args_func = kwargs.pop('callback', lambda request, *args, **kwargs: {})
Either return a keyword argument named 'callback' (which if passed in, is supposed to be a function that accepts request and return a dictionary), and if it wasn't, return a lambda function that only returns an empty dictionary.
I'm not sure what the specific use is for the extra context. You could use it to run arbitrary snippets of code without modifying or subclassing ajax_validation...
It might help you to run this code, and put a debugger breakpoint in somewhere so you can step through and examine the variables and methods. You can do this by simply putting this line where you want to break:
import pdb; pdb.set_trace()
and you will be dumped into the debugger in the console.

How to Pass Django form values to a model class method

What is the best way to pass request information to a model class method?
I'm wondering whether I have my logic in the wrong place. Maybe I need to move it out of my model.
I want to be able to pass in POST variables or a form to filter the model by country or institution.
I can't do that from the template, but the question is whether I should do that from within the model or controller somehow.
My Model:
class AccountExtra(User):
def myPendingPaymentSchedules(self, status=1, **args):
if self.is_staff: # status = approved by MFI
schedules = PaymentSchedule.objects.select_related(depth=3).filter(active=True)
if country:
schedules = schedules.filter(country=country)
if institution:
schedules = schedules.filter(institution=institution)
return schedules
My Controller:
myAccount = get_object_or_404(AccountExtra, id=request.user.id)
My Template
{% for sample in myAccount.myPendingPaymentSchedules %} # Can't pass parameters for country, etc
Yes, I'd say your logic is in the wrong place. I don't know where the values are coming from that you're trying to pass into myPendingPaymentSchedules, but it seems like it should be done in the view rather than the template. Then you can pass the resulting schedules directly into the template context.
(By the way, your naming scheme is not very Pythonic: I'd use my_account and my_pending_payment_schedules - see PEP8.
Thanks for the feedback. I've done a little bit of research about how to access business login from within templates and I thought I'd provide an update in case others find this question in the search results:
There are two cases in which the parameters for the method need to be passed:
Case #1) Passing paramaters for a single value
If we only have a single account, we can simply pass them to the model through a single call in the controller, and pass the result to the template as a single context variable.
Model
class AccountExtra(models.Model):
..
def my_pending_payment_schedules(self, status=1, country=None, institution=None)
if self.is_staff:
schedules = payment_schedule.objects.filter(active=True)
if country:
schedules = schedules.filter(product__country=country)
if institution:
schedules = schedules.filter(product__institution=institution)
return schedules
Controller
my_account = get_object_or_404(AccountExtra, id=request.user.id)
form = staff_approval_form(request.POST)
if form.is_valid():
cd = form.cleaned_data
pending_schedules = my_account.my_pending_payment_schedules(
country=cd.get('country', None),
institution=cd.get('institution', None)
)
c = RequestContext( request, {
'form': form,
'pending_schedules': pending_schedules,
})
return render_to_response(
'my/approvals/approvals_index.html',
context_instance=RequestContext(request, c)
)
Template
{% for sample in pending_schedules %}
Case #2: Passing parameters for multiple values
If however, we are trying to iterate through multiple users's pending schedules who each require different parameters, we can't use a simple 'pending_schedules' variable.
We have to either turn that variable into a dictionary to store the results of multiple users.
A collegue of mine developed a template tag that allows you to access the dictionary by key, as you iterate through the loop.
Templatetags
#register.filter
def hash(obj, key):
"""return hash lookup of key in object
If the key can be hard-coded into the template, then the normal dot-notation
is sufficient (obj.key). But if the key is referenced by a name in the
template context then this hash filter becomes useful.
Template usage: obj|hash:key
"""
return obj[key]
Template:
for user in users:
for sample in pending_schedules|hash:user.id
Do something
endfor
endfor