I am building a website and I want various views that will ask the user to request a quote from our page. I want to keep the code as DRY as possible so I am writing a view quote which will receive the quote requests from various views and, if there is a validation error redirect back to the page that made the request. I managed to solve this using the super bad practice 'global variables'. I need a better solution, I would like redirecting to respective view with the current form so I can iterate through the form.errors. Here is my code:
def send_quote(request):
form = Quote(request.POST)
if form.is_valid():
# do stuff when valid
return redirect('Support:thanks', name=name or None)
quote_for = request.POST['for_what']
global session_form
session_form = form
return redirect('Main:' + quote_for) # Here I would like to send form instead of storing in global variable`
You can use the HttpResponseRedirect function, and pass as argument the page that made the request.
return HttpResponseRedirect(request.META.get('HTTP_REFERER'))
All the META data is store on a dictionary, if you want to learn more check the documentation.
https://docs.djangoproject.com/en/dev/ref/request-response/#django.http.HttpRequest.META
If you redirect to the referrer, form.errors will be empty, as redirection is always a GET request.
I can think of two solutions to your problem:
Submit forms asynchronously using JavaScript and so populate the errors
Make all the views containing the form support POST - one way to do this would be to create a base class that inherits from FormView
The second option is a typical way of handling forms in Django - you process both POST and GET inside the same view.
After two days of searching I finally found the answer. Instead of saving form in request.session I just save request.POST and then redirect. Here is the code:
def send_quote(request):
form = Quote(request.POST)
if form.is_valid():
# do stuff when valid
return redirect('Support:thanks', name=name or None)
quote_for = request.POST['for_what']
request.session['invalid_form'] = request.POST
return redirect('Main:endview')
def endview(request):
session_form = request.session.pop('invalid_form', False)
if session_form:
form = Quote(session_form)
# render template again with invalid form ;)
Now I can repeat this with all the views I want and just change the what_for input of each form to match the respective view (Like I intended).
Related
In a Django 1.11 app I've created a large form for users to update a model instance, but based on what the users change there may be multiple other forms I'd like to redirect them to afterwards.
What's the best practise for dynamically chaining multiple forms (dynamic workflow)?
I can't find anything helpful in the Django docs or other questions on here.
E.g. (extremely simplified) view for model update form:
def asset_edit(request, pk):
asset = get_object_or_404(Asset, pk=pk)
current_location_concat = "{} {} {}".format(asset.location_building, asset.location_room, asset.location_area)
if request.method == "POST":
form = EditAsset(request.POST, request.FILES, instance=asset)
if form.is_valid():
asset = form.save(commit=False)
# setting some things...
asset.save()
new_location_concat = "{} {} {}".format(asset.location_building, asset.location_room, asset.location_area)
if current_location_concat != new_location_concat:
check_relatives = True # redirect to check_relatives form
if asset.equipment_id:
if Asset.objects.filter(equipment_id=asset.equipment_id).count() > 1:
duplicate_assets = True # redirect to check_duplicates form
# if check_relatives and duplicate_assets:
# redirect to check_duplicates form and then on to check_relatives form
return redirect("asset_detail", pk=asset.pk)
I know I could just add a new URL for my check_duplicates form with a "next" (or similar) parameter, pass a "next" value that the check_duplicate view maps to one or more other forms (just "check_relatives" in this instance) and redirects to this when the check_duplicates form is submitted, but is this the best practise?
Especially given that the number of forms that may need to be chained this way could get quite large and the logic complex!
I have been using formtool's WizardView for this and I have tried the 'stuff-everything-into-the-post-method' approach as well.
WizardView looks like the right fit for what you are trying to do.
For example, it allows you to skip steps in your workflow based on function conditions - removing this bit of logic from your workflow, which makes the whole view easier to read.
I have found it a pain to write tests for such views as you have to account for the WizardView's very own internal structure while testing, but overall it's definitely better than writing a 1000 lines post-method (might as well code in BASIC then).
I am building a web application using django. I need to take a string input from the user and process it using a method I have written myself. How to achieve this in Django? Here are the things I need to do
Get User Input userinput = (string) On start page
Put this string as an argument in my method MyMethod(userinput) and Run it in the backend
Display what MyMethod() returns on another page.
I suggest that you start from django tutorial: https://docs.djangoproject.com/en/1.9/intro/tutorial01/
Basically, what you are going to need is form with one text field, HTML template that will render the form, view that will render HTML template with instance of a form when GET request arrives and call your MyMethod with value from form when POST request arrives and URL rule to call your view function on some URL.
Without additional data or any attempt to solve it and concrete problem you encounter - I can hardly offer more help.
You need to create a model with fields which you want to update by user input, then create a form based on this model. Then import this in a view and render it in a template
simple example:
forms.py:
class InputForm(forms.ModelForm):
class Meta:
model = YourModel
fields = ['fields_from_YourModel']
views.py:
from .forms import InputForm
def user_input(request):
input = CustomUser.objects.get(pk=request.user.pk)
if request.POST:
form = ProfileForm(request.POST, instance=input)
if form.is_valid:
form.save()
else:
form = ProfileForm()
return render(request, 'input.html', {'form':form})
Other steps more easier for beginner, you'll find examples in docs
Below is the code from views.py where I am using render_to_response to direct the user to done.html along with a dictionary of variables. But, I actually want to direct the user to a url /home_main/#signin_completeand pass the dictionary of variables that are callable. Can someone please suggest if there is a way of doing this ?
def done(request):
"""Login complete view, displays user data"""
scope = ' '.join(GooglePlusAuth.DEFAULT_SCOPE)
return render_to_response('done.html', {
'user': request.user,
'plus_id': getattr(settings, 'SOCIAL_AUTH_GOOGLE_PLUS_KEY', None),
'plus_scope': scope
}, RequestContext(request))
EDIT
My requirement is to render a second page (signin_complete) from a multipage html (home_main.html). Currently, I am achieving this by redirecting the user with HttpResponseRedirect as shown below. But, I would also like to pass a callable dictionary that I can use in the second page of the multipage html.
Here is a link that gives more information of a multipage html under multipage template structure.
def done(request):
"""Login complete view, displays user data"""
scope = ' '.join(GooglePlusAuth.DEFAULT_SCOPE)
return HttpResponseRedirect('/home_main/#signin_complete')
Below is the dictionary that I would like to pass to the second page (sign_complete) in the multi page html.
{
'user': request.user,
'plus_id': getattr(settings, 'SOCIAL_AUTH_GOOGLE_PLUS_KEY', None),
'plus_scope': scope
}
The session is the place to store data between requests.
# in done():
request.session['dict_to_save'] = my_dict_to_save
return redirect('/new/url/to/redirect/to')
# in the new view:
values_from_session = request.session.pop('dict_to_save', None)
It would be much better if you would redirect request inside done() method, like the docs advises you to do.
This solves your issue as well, since you can define your own url to redirect to, there's related SO question of how to add hash tags when redirecting.
Hi Stackoverflow people,
In my Django project I created a form to register users. This forms can be called through a specific url -> view method. Once the user has filled in the form, presses submit, the same view method will be called and if form.is_valid() is true, then ... simply a standard form, nothing special.
Now, I would like to integrate this little form on every page, and therefore I would like to add it to the base template. I have read that I could populate the form variable through a context_processor, but could I define the process after the submission of the form?
I have created the context_processor.py (as below), added the context_processor to the TEMPLATE_CONTEXT_PROCESSOR dir in the settings (as described here):
from app.forms import Form
def registration_form(request):
return {
registration_form : Form()
}
First of all, the form variable won't be displayed.
And secondly, how do I manipulate the form submission?
I think I misunderstanding the context_processor of Django and would be more than happy about comments on the overall process.
Thank you!
how are you trying to access to form in your template? you probably don't want to use a function name as your dictionary key, maybe you want
return {
'registration_form': Form(),
}
not sure what you mean by manipulate the form submission, but i guess you'd need all the form processing logic in your context processor
if request.POST:
form = Form(request.POST)
# validate etc
instead of creating context processor, create template tag for the purpose and place the tag in base.html
for form submission and displaying errors use ajax, and front-end validations.
I've seen Django's samples and I can see they have decent error handling. However I want to see if there is yet a better approach, a general pattern to handle form validation errors in Django. This is the sample I found here:
def contact(request):
if request.method == 'POST': # If the form has been submitted...
form = ContactForm(request.POST) # A form bound to the POST data
if form.is_valid(): # All validation rules pass
# Process the data in form.cleaned_data
# ...
return HttpResponseRedirect('/thanks/') # Redirect after POST
else:
form = ContactForm() # An unbound form
return render_to_response('contact.html', {
'form': form,
})
In particular, I was wondering:
How can the view in "/thanks/" be sure that the form was validated? Are there any common ways to pass the successful validation of the form to the next view? Or do I need to do something manually such as setting a flag in request's session?
How can one write this code in a way that when form is NOT valid and the page is shown with errors upon submission, if user refreshes the browser it wouldn't ask the user if they want to POST data again?
EDIT: With regards to #1 I am referring to cases like user manually entering the '/thanks/' url or going back and forth through history pages and accidentally openning it without any form being validated. (Do we still show the "thanks" page? or we need to somehow re-validate why we are in thanks view).
The view can be sure that the form is validated because it will only be called if the form is valid...
If the page is generated through a post request the browser will always ask you that when hitting refresh... I guess the only way to avoid this would be redirecting to another page!
How can the view in "/thanks/" be sure that the form was validated?
form.is_valid() should thoroughly check any field or - if necessary - any combination, cornercase, etc. That's basically it. The views knows, the form was valid if it renders. There is no need to include redundant information in the session.
How can one write this code in a way that when form is NOT valid and the page is shown with errors upon submission, if user refreshes the browser it wouldn't ask the user if they want to POST data again?
I am not sure what the point would be. The form contains errors and the user may correct them or leave. To render a page that would not ask for form resubmission, one could use a redirect, just as in the valid case. The error markup would have to be done manually in that case.