I have a django application and for a particular form,the data comes from different models with one common field(id) across all models.Instead of using multiple forms and same id for all forms,I want to use a single form to take data from multiple models.How can this be done?
Specify your form as provided in the django docs: https://docs.djangoproject.com/en/1.10/topics/forms/#building-a-form-in-django
Specify the view e.g.
view.py
def get_name(request):
id = request.kwargs['id'] # Get the id from url or however you want to get the id
item = Item.objects.get(name_id=id)
item2 = Item2.objects.get(name_id=id)
# if this is a POST request we need to process the form data
if request.method == 'POST':
# create a form instance and populate it with data from the request:
form = NameForm(request.POST)
# check whether it's valid:
if form.is_valid():
# process the data in form.cleaned_data as required
# ... e.g.
item.name = form.cleaned_data['name']
item2.name = form.cleaned_data['name2']
item.save()
item2.save()
# redirect to a new URL:
return HttpResponseRedirect('/thanks/')
# if a GET (or any other method) we'll create a blank form
else:
# This is for updating the "name" objects
form = NameForm(initial={'name': item.name, 'name2': item2.name})
# for creating: (but I guess you don't need creating)
# form = NameForm()
return render(request, 'name.html', {'form': form})
Handle the form in the template as you normally would.
Related
I'm new to django but something I don't understand is the need for accommodating both the GET and POST request types when developing a form. Please refer to code below from django docs:
from .forms import NameForm
def get_name(request):
# if this is a POST request we need to process the form data
if request.method == 'POST':
# create a form instance and populate it with data from the request:
form = NameForm(request.POST)
# check whether it's valid:
if form.is_valid():
# process the data in form.cleaned_data as required
# ...
# redirect to a new URL:
return HttpResponseRedirect('/thanks/')
# if a GET (or any other method) we'll create a blank form
else:
form = NameForm()
return render(request, 'name.html', {'form': form})
The reason this confuses me is because I have developed a GET based form and it is working and I have no need for the POST portion above? See below:
# views.py
def simplifier_form(request):
form = LabelForm()
return render(request, "simplifier.html", {"form": form})
def process_simplifier(request):
label_name = request.GET.get('labels')
results = Disturbance.objects.filter(labeldisturbances__label_name=label_name)
painsresults = Pain.objects.filter(disturbances__pk__in=results).distinct()
total_disturbances = Disturbance.objects.filter(pain__pk__in=painsresults)
total_labels = Label.objects.filter(disturbances__pk__in=total_disturbances).distinct()
context = {'results': results, 'painsresults': painsresults, 'total_disturbances': total_disturbances, 'total_labels': total_labels}
return render(request,'process_simplifier.html', context)
# forms.py
class LabelForm(ModelForm):
labels = forms.ModelChoiceField(
queryset=Label.objects.all(),
to_field_name='label_name',
widget=forms.Select(attrs={'class': 'labels'}),
)
class Meta:
model = Label
fields = ['labels']
So why do the django docs and most examples include code for both methods when you only really use one like in my example above?
The question is... How do you want to process your from when submitted on POST?
Remember, your form can also be submitted on GET... You can decide what you would want to do if submitted on GET.
I am trying to use same view for creating form and updating any object.
My code is as below, I tried in many ways nothing is working, since I am excluding the shof from form and adding it after form.is_valid() it makes lot of confusion. If I update it creates new object. I have two urls one without ql (create new) and one with ql (update existing), I have a class vdview which provides v.shof which needs to applied in the f.shop in form. please help fix this,
#csrf_protect
#login_required
def addmenu(request, qs, ql=None):
v = vdview(request, qs)
ctgobj = get_object_or_404(v.shopcategs, pk=ql) if ql else None # ctgobj = ShopCtg(shop=v.shof)
if ql:
form = ShopCtgForm(instance=ctgobj) # Tried ShopCtgForm(instance=ctgobj, data=request.POST)
else:
form = ShopCtgForm(data= request.POST)
if request.method == 'POST':
if form.is_valid():
f=form.save(commit=False)
f.shop = v.shof
f.save()
#form.save_m2m()
return redirect('vendor-shop', qs) #thing='%s added' %f.name)
else:
pass
#else:
# form = ShopCtgForm()
return render(request,'vendorshop.html', {'shop':v.shof, 'shopcategs':v.shopcategs, 'form': form,
'heading':'Create New Category', 'createcateg': 'createcateg', 'pkaddmenupk':'y' } )
Use try blocks to handle both scenarios. The simplified example below will look for a given model instance pk and if it doesn't find it, will assume you want to create it. try will prevent django from throwing an error if the model instance doesn't exist. Rather, it will just return the empty model form.
It does this first to render the correct form in the template (the first try block) then again in the second try block after request.method == 'POST': to submit new data or update existing data.
Views.py
from .models import Books
from .forms import BookForm
def create_and_update_book_view(request, pk):
books = Books.objects.get(id=pk)
try: # get pre-populated form with model instance data (for update)
form = BookForm(instance=books.id)
except: # If it doesn't exist, show an empty form (for create)
form = BookForm(request.POST or None)
if request.method == 'POST':
try: # Do the same as above
form = BookForm(instance=books.id)
except: # Same as above
form = BookForm(request.POST or None)
if form.is_valid():
form.save()
return render(request, "create_and_update_book_page.html", {'form':form})
After form.is_valid(), we get form.cleaned_data. How can i use this cleaned data on the next page.
For example, after the form page is processed we redirect the customer to next page, where I want to use the cleaned_data's info like name, contact, address..etc fields to be shown in next page.
def ind(request):
if request.method == 'POST':
form = form_name(request.POST)
if form.is_valid():
print(form.cleaned_data)
return render(request, 'app_one/abc.html', {'data': form.cleaned_data})
# form.save(commit=True)
# return render(request,'app_one/index.html')
else:
form=form_name()
return render(request,'app_one/index.html',{'form':form)
We will have a validated data after calling the form.is_valid() method. Once we have a validated data then we can use as we like.
For your case
customer details which are filled on the first page need show those details on the second page as receipt.
You can create a model named Reciept and save the details in the model for future reference. If you want these details in the other page views then simply pass the model object in context to render the details.
You can use the cleaned data like below
def ind(request):
if request.method == 'POST':
form = form_name(request.POST)
if form.is_valid():
context = {}.update(form.cleaned_data)
return render(request, 'app_one/abc.html', context)
# form.save(commit=True)
# return render(request,'app_one/index.html')
else:
form=form_name()
return render(request,'app_one/index.html',{'form':form)
Example Form:
class MyForm(forms.Form):
reciept_num = forms.CharField()
consider above form as an example
You can access the reciept_num data in template using the name reciept_num.
You can assign the cleaned_data to variables as usual for forms
e.g. your_data=form.cleaned_data['your_data']
After that, pass those variables to context.
e.g. context = {
'your_data':your_data
}
Lastly return the template.
e.g. return(request,'template.html',context=context)
At the 'template.html', use the variables as {{your_data}}.
Situation
Using Django 1.5, I am using forms.ModelForms to let the user edit database contents. However I can't get the form to update the database upon form.save().
Each of my models correspond to a setting form (the application is a the direct porting of a desktop software in which the user can store several settings). I needed to implement a Reset to default feature, so I thought of having a default object (imported with Django fixtures) which I would use only to reset a second one. The user would only interact with the second model.
pk=1 refers to the base object
pk=2 refers to the custom object
I have several forms on the same page (only foobar here), so basically this what I planned to do:
No POST data
Building form from either pk=1 or pk=2, depending pk=2 has been found or not
Rendering the forms to the template
AJAX request, with POST datas
Getting form content
Checking whether or not the user has permission to edit the model (checksum)
Update the model form POST datas
Returning AJAX response
Code
I have put two debug prints to illustrate the issue I am facing. The form I fetch doesn't seem to be bound to my model.
# Response codes to use in the template
RESPONSES = {
200: {'code':'0xB16B00B5', 'message':'Success'},
400: {'code':'0x8BADF00D', 'message':'Form is not valid'},
403: {'code':'0xBAADF00D', 'message':'No permission to edit the database'},
501: {'code':'0xDEADC0DE', 'message':'POST datas not found'},
}
# Those are the setting labels
TYPES = {
'foobar': {'model':FooBar, 'form':FooBarForm },
}
def index(request):
# Handling form datas
if request.method == 'POST':
response = HttpResponse(simplejson.dumps({'code':RESPONSES[501]['code']}), 'application/json')
for label in TYPES:
# Filtering the right form to handle
if label in request.POST:
model = _fetch_setting(label, mode='model')
form = _fetch_setting(label, mode='form', post=request.POST)
checksum = model.checksum # Somehow, 'form.is_valid()' is altering 'model', need to backup the checksum
if form.is_valid():
# The user has permission to edit the model
if form.cleaned_data['checksum'] == checksum:
if form.has_changed():
print form.cleaned_data['foo'] # Outputs the form data, as expected
form.save()
print model.foo # Outputs the old data
model.checksum = str(uuid4()).replace('-', '')
model.save()
response = HttpResponse(simplejson.dumps({'code':RESPONSES[200]['code']}), 'application/json')
# This one does not
else:
response = HttpResponse(simplejson.dumps({'code':RESPONSES[403]['code']}), 'application/json')
break # We are still inside the label loop
# The form is not valid
else:
response = HttpResponse(simplejson.dumps({'code':RESPONSES[400]['code']}), 'application/json')
# Form not submitted yet, building the HTML forms
else:
forms = {}
label = 'foobar'
for label in TYPES:
forms[label] = _fetch_setting(label, mode='form')
context = {'errors':RESPONSES, 'forms':forms}
response = render(request, 'home/index.html', context)
return response
# Return a setting object (model or form) corresponding to the given label
def _fetch_setting(label, mode='model', post=None):
try:
result = None
default = TYPES[label]['model'].objects.get(pk=1)
try:
model = TYPES[label]['model'].objects.get(pk=2)
except TYPES[label]['model'].DoesNotExist:
model = TYPES[label]['model'].objects.create(
checksum = default.checksum,
foo = default.foo,
bar = default.bar,
)
if mode == 'model':
result = model
if mode == 'form':
print model
result = TYPES[label]['form'](data=post, instance=model) # The 'instance' attribute doesn't seem to be applied
except KeyError:
result = None
finally:
return result
Update
07.10
It does work when I pass the instance to bound with to _fetch_setting. So I guess this issue is coming from the form validation.
def _fetch_setting(label, mode='model', post=None, instance=None):
# ...
if mode == 'form':
if instance:
model = instance
result = TYPES[label]['form'](data=post, instance=model)
# ...
As I commented in my code, form.is_valid() seems to alter the object.
Will flag as answered if no one come with a clean solution.
The issue is, you are creating a new model object with each form.save()
You need to update the same model object with commit=False
if form.cleaned_data['checksum'] == checksum:
if form.has_changed():
print form.cleaned_data['foo'] # Outputs the form data, as expected
model = form.save(commit=False)
model.checksum = str(uuid4()).replace('-', '')
model.save()
From the fabulous manual:
The first time you call is_valid() or access the errors attribute of a ModelForm triggers form validation as well as model validation. This has the side-effect of cleaning the model you pass to the ModelForm constructor. For instance, calling is_valid() on your form will convert any date fields on your model to actual date objects. If form validation fails, only some of the updates may be applied. For this reason, you’ll probably want to avoid reusing the model instance passed to the form, especially if validation fails.
First Post, so forgive any noob-iness -- I'm trying to create a multi-page product sign-up form. I can get the form to display and the submit button, but I can't find any examples of URL patterns for my urls.py file. I found another similar question with the following suggestions:
"You need to write a view to handle your request.(did that) You need to edit urls.py to map your quiz url to the function in views.py (trying, but failing). So when a request with that quiz url comes Django applies that view function.
When I Redirect the user to the new url is the problem. I can't seem to find an example of what the next pattern should be. Here's my urls.py code (index.html and details.html are my templates so far):
url(r'^signup/$', 'signup.views.select_product', name='select_product'),
url(r'^signup/(?P<product_id>\d+)/$', 'signup.views.subscriber_signup', name='subscriber_signup'),
#...
Here's my view code:
def select_product(request):
title = "get yourself an e-edition. wurd."
pform = ProductForm(request.POST)
if request.method == 'POST': # If the form has been submitted...
pform = ProductForm(request.POST) # A form bound to the POST data
if pform.is_valid(): # All validation rules pass
# Process the data in form.cleaned_data
# ...
return HttpResponseRedirect('signup/index.html') # Redirect after POST
else:
form = ProductForm() # An unbound form
return render_to_response('signup/index.html', {'title': title, 'pform': pform}, context_instance=RequestContext(request))
def subscriber_signup(request, product_id):
signup = Product.objects.get(id=product_id)
title = "get yourself an e-edition. wurd."
sform = SubscriberForm(request.POST)
if request.method == 'POST': # If the form has been submitted...
sform = SubscriberForm(request.POST) # A form bound to the POST data
if sform.is_valid(): # All validation rules pass
# Process the data in form.cleaned_data
# ...
return HttpResponseRedirect('signup/detail.html') # Redirect after POST
else:
sform = SubscriberForm() # An unbound form
return render_to_response('signup/detail.html', {'title': title, 'sform': sform, 'signup': signup,}, context_instance=RequestContext(request))
Or use Django's form wizard which was designed for this.
so part of the problem was I was using the (User) model in my Subscriber class, which the SubscriberForm was based. I ditched that and made a form based on a normal class with the objects defined individually.
Here's the URL patterns that eventually worked.
url(r'^signup/$', 'signup.views.select_product', name='select_product'),
url(r'^signup/(?P<product_id>\d+)/$', 'signup.views.subscriber_signup', name='subscriber_signup'),
url(r'^signup/(?P<product_id>\d+)/thankyou/$', 'signup.views.thankyou', name='thankyou'),
thanks for the responses.
Anthony