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.
Related
I just want to know how can I set initial values to empty_form.
I do create the Inlines with initial values for extra forms without problem, but, when user clicks to Add button, the fields I expect it have the initial values show up empty, and I hope it have the same initial values than extra forms.
How could I make the empty_form to be filled with initial data?
Thanks in advance.
Django doesn't really provide a way to set initial values for empty forms. I've found a couple ways to work around this:
Set the field values dynamically in javascript.
Overwrite the empty_form property for your formset.
example:
formset = formset_factory(MyClass, **kwargs)
empty = formset.empty_form
# empty is a form instance, so you can do whatever you want to it
my_empty_form_init(empty_form)
formset.empty_form = empty_form
I had a similar problem and what finally worked for me was using Django Dynamic Formset. What DDF does is instead of using the empty form to create the new formset, it uses one of the extra_forms as a template. The default behavior is to clear all field values from the extra_form before inserting the HTML to the DOM, but you can use the keepFieldValues setting to specify the ones you want to keep.
In my case I wanted to keep all hidden field values:
$(function() {
$('#myForm_table tbody tr').formset({
keepFieldValues: 'input:hidden',
}
});
});
Of course you can bypass Django Dynamic Formsets and implement your own add/delete code with Javascript if you prefer.
Accepted answer didn't work for me, hopefully this will help someone in the future, this is my solution:
Create a new class based on BaseInlineFormSet
Override empty_form
Create a FormSet with inlineformset_factory(formset=YourBaseInlineFormSet)
Create a formset instance and pass parameters to initial on the formset instance
Add the field on the HTML as usual
I used BaseInlineFormSet, but probably will work with other types of FormSet
verification is the name of the field for my example.
forms.py
class YourBaseInlineFormSet(forms.BaseInlineFormSet):
#property
def empty_form(self): # This is almost the same as Django 3.1 code
form = self.form(
auto_id=self.auto_id,
prefix=self.add_prefix("__prefix__"),
empty_permitted=True,
use_required_attribute=False,
initial={"verification": self.initial_extra[0]["verification"]}, # This is the extra parameter
**self.get_form_kwargs(None),
)
self.add_fields(form, None)
return form
YourFormSet = forms.inlineformset_factory(
SomeObject,
SomeRelatedObject,
fields="__all__",
widgets={"verification": forms.HiddenInput},
formset=YourBaseInlineFormSet,
)
views.py
from .forms import YourFormSet
def your_view(request):
formset = YourFormSet(
data=request.POST or None,
instance=object,
queryset=object.related_objects.all()
initial=[{"verification": verification} for a in range(FormSet().total_form_count())],
)
return render(request, template, context={'formset': formset})
template.html
<div id="empty_form" style="display:none">
{{ formset.empty_form }}
</div>
Working on Django 3.1
There is at least one way to do this: Specify the default value on your model Field.
Of course, this may have side effects, depending on your implementation of the model.
As #jkk-jonah mentioned, BaseFormSet does not provide a way to set initial values in the empty_form. However, a small change can provide a simple solution.
The following provides a way to supply the FormSet instance with empty initial values without disrupting its base behavior.
from django.forms.formsets import BaseFormSet
class FormSetWithDefaultEmptyFormInitials(BaseFormSet):
"""This formset enables you to set the initial values in ``empty_form``.
Usage: ``formset_factory(..., formset=FormSetWithDefaultEmptyFormInitials)``
"""
def __init__(self, *args, **kwargs):
if 'empty_initial' in kwargs:
self._empty_initial = kwargs.pop('empty_initial')
super().__init__(*args, **kwargs)
def get_form_kwargs(self, index):
"""Augmented to return the empty initial data
when the index is ``None``,
which is the case when creating ``empty_form``.
"""
if index is None:
kwargs = self.form_kwargs.copy()
if self._empty_initial:
# Assign the initial value passed to the Form class.
kwargs['initial'] = self._empty_initial
else:
kwargs = super().get_form_kwargs(index)
return kwargs
Then to use this you'd do something like:
NonEmptyFormSet = formset_factory(
BringYourOwnForm,
min_num=1,
extra=1,
formset=FormSetWithDefaultEmptyFormInitials,
)
# Let's say your form has name and address fields...
empty_form_initial_values = {'name': 'default name', 'address': 'default address'}
formset = NonEmptyFormSet(empty_initial=empty_form_initial_values)
asset formset.empty_form.initial == empty_form_initial_values
In my implementation empty_form is used to provide a template for frontend javascript to add additional forms to the formset. Thus, this allows me to set the initial values for that all of the forms in that formset.
Note, this does not take the place of initial values to the minimum number of forms within the formset (e.g. formset_factory(min_num=2, ...)). Therefore, it is necessary to assign those through the standard initial keyword argument.
Tested with Django 3.2.
See also the standard implementation of get_form_kwargs.
This partially extends the answer given by #RobertPro. Or at least, I used their answer as the stepping stone to my own solution.
Newbie question:
I need to accept a parameter in a form from a method in views.py but it gave me troubles. In the view I created a method with following snippet:
def scan_page(request):
myClient = request.user.get_profile().client
form = WirelessScanForm(client = myClient) # pass parameter to the form
and in the forms.py I defined the following form:
class WirelessScanForm(forms.ModelForm):
time = forms.DateTimeField(label="Schedule Time", widget=AdminSplitDateTime())
def __init__(self,*args,**kwargs):
myClient = kwargs.pop("client") # client is the parameter passed from views.py
super(WirelessScanForm, self).__init__(*args,**kwargs)
prob = forms.ChoiceField(label="Sniffer", choices=[ x.sniffer.plug_ip for x in Sniffer.objects.filter(client = myClient) ])
But django keeps giving me error saying: TemplateSyntaxError: Caught NameError while rendering: name 'myClient' is not defined(This error happens in the query)
I'm afraid it would be something stupid missing here, but I cannot really figure out why. Please help, thanks.
Assuming I've corrected your formatting properly, you have an indentation issue: prob is outside __init__, so doesn't have access to the local myClient variable.
However if you bring it inside the method, it still won't work, as there are two other issues: first, simply assigning a field to a variable won't set it on the form; and second, the choices attribute needs a list of 2-tuples, not just a flat list. What you need is this:
def __init__(self,*args,**kwargs):
myClient = kwargs.pop("client") # client is the parameter passed from views.py
super(WirelessScanForm, self).__init__(*args,**kwargs)
self.fields['prob'] = forms.ChoiceField(label="Sniffer", choices=[(x.plug_ip, x.MY_DESCRIPTIVE_FIELD) for x in Sniffer.objects.filter(client = myClient)])
Obviously replace MY_DESCRIPTIVE_FIELD with the actual field you want displayed in the choices.
I have an extended UserProfile for registering new users. My user_created function connects to signals sent upon registering basic User instance and creates new UserProfile with extended fields from my form. Here's the code :
from registration.signals import user_registered
from accounts.forms import ExtendedRegistrationForm
import accounts
from accounts.models import UserProfile
def user_created(sender, user, request, **kwargs):
form = ExtendedRegistrationForm(request.POST, request.FILES)
data = UserProfile(user=user)
data.is_active = False
data.first_name = form.data['first_name']
data.last_name = form.data['last_name']
data.pid = form.data['pid']
data.image = form.data['image']
data.street = form.data['street']
data.number = form.data['number']
data.code = form.data['code']
data.city = form.data['city']
data.save()
user_registered.connect(user_created)
Problem is that on this form I have an image field for avatar. As you can see from the code, I'm getting data from form's data list. But apparently imageField does not send it's data with POST request(as I'm getting MultiValueDictKeyError at /user/register/, Key 'image' not found in <QueryDict...) so I can't get it from data[] .
alt text http://img38.imageshack.us/img38/3839/61289917.png
If the usual variables are inside 'data', where should I look for files ? Or is the problem more complicated ? Strange thing is that my form doesn't have attribute cleaned_data... I was using dmitko's method here : http://dmitko.ru/?p=546&lang=en . My :
forms : http://paste.pocoo.org/show/230754/
models : http://paste.pocoo.org/show/230755/
You should be validating the form before using it, which will create the "cleaned_data" attribute you're used to. Just check form.is_valid() and the "cleaned_data" attribute will be available, and should contain the file.
The form's "data" attribute is going to be whatever you passed in as its first initalization argument (in this case, request.POST), and files are stored separately in the "files" attribute (whatever you pass in as the second argument, in this case, request.FILES). You don't want to be accessing the form's "data" or "files" attributes directly, as, if you do, you're just reading data straight from the request and not getting any benefit from using forms.
Are you sure the <form enctype="..."> attribute is set to multipart/form-data ? Otherwise the browser is not able to upload the file data.
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)
I have a form 'in the wild' that takes many different variables - which may or may not be populated.
try:
app_version = request.REQUEST["appVersion"]
except:
app_version = ''
try:
app_name = request.REQUEST["appName"]
except:
app_name = ''
try:
app_code_name = request.REQUEST["appCodeName"]
except:
app_code_name = ''
Is there a tighter way to accomplish this?
app_version = request.REQUEST.get("appVersion", "")
get(key, default) is a method implemented on Python dicts. If the key exists in the dictionary, its value is returned; if the key does not exist, the specified default value is returned. In Django, request objects are dictionary-like objects, so get is also defined for them in the same manner.
If these variables are intended to populate a form, then you can safely pass the request.POST object directly into the form constructor.
if request.method == 'POST':
form = MyForm(request.POST)
The form will automatically pass the correct values to the correct form fields and use defaults for keys that don't exist and will still create blank fields for missing keys (see addendum).
If you are trying to process a form, it is still better to create a form object as above, and read out the values from that object.
if request.method == 'POST':
form = MyForm(request.POST)
if form.is_valid():
# You may process these variables here
print form.appVersion
print form.appName
print form.appCodeName
Remember, validation code is best placed in the form class as well. That way, if form.is_valid() returns True, then you know you have a clean dataset to work with.
Note: Django docs recommend using request.POST or request.GET directly rather than the amalgamated variable request.REQUEST, as it is more explicit.
Addendum:
It is important to understand the difference between bound and unbound forms in this case. If you create an unbound form with form = MyForm(), then when the form is instantiated, it will fill in all fields with the initial property of each field (if it exists). For example, with this code:
from django import forms
class MyForm(forms.Form):
appVersion = forms.CharField(initial='1.0')
appName = forms.CharField()
appCodeName = forms.CharField()
the form will be initialized with appVersion having a value of '1.0'. However, if you bind a POST request to a form like this: form = MyForm(request.POST), then the initial properties are ignored. That means if the POST dict does not include an appVersion key, then that field will be left blank. As long as the field is not required, your form will still validate, and you can modify form.appVersion in the view after validation.
If you have many fields, a more compact version might be:
defaults = { 'field1' : 'val1', 'field2' : 'val2', ...}
defaults.update(request.POST)