232

I have a template page expecting two forms. If I just use one form, things are fine as in this typical example:

if request.method == 'POST':
    form = AuthorForm(request.POST,)
    if form.is_valid():
        form.save()
        # do something.
else:
    form = AuthorForm()

If I want to work with multiple forms however, how do I let the view know that I'm submitting only one of the forms and not the other (i.e. it's still request.POST but I only want to process the form for which the submit happened)?


This is the solution based on the answer where expectedphrase and bannedphrase are the names of the submit buttons for the different forms and expectedphraseform and bannedphraseform are the forms.

if request.method == 'POST':
    if 'bannedphrase' in request.POST:
        bannedphraseform = BannedPhraseForm(request.POST, prefix='banned')
        if bannedphraseform.is_valid():
            bannedphraseform.save()
        expectedphraseform = ExpectedPhraseForm(prefix='expected')
    elif 'expectedphrase' in request.POST:
        expectedphraseform = ExpectedPhraseForm(request.POST, prefix='expected')
        if expectedphraseform.is_valid():
            expectedphraseform.save() 
        bannedphraseform = BannedPhraseForm(prefix='banned')
else:
    bannedphraseform = BannedPhraseForm(prefix='banned')
    expectedphraseform = ExpectedPhraseForm(prefix='expected')
Armance
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Adam Nelson
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    Isn't there a logical error with your solution? If you post 'bannedphrase', expectedphraseform will not get populated. – Ztyx Sep 26 '11 at 18:39
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    This will handle only one form at a time, the question is about handling the multiple forms at the same time – shining Apr 06 '16 at 06:34
  • All these answers are helpful, but they don't have a solution for an invalid form. Does anybody have any ideas how to send back an invalid form when two forms might be invalid? – greenie-beans Jan 12 '21 at 17:59

12 Answers12

164

You have a few options:

  1. Put different URLs in the action for the two forms. Then you'll have two different view functions to deal with the two different forms.

  2. Read the submit button values from the POST data. You can tell which submit button was clicked: How can I build multiple submit buttons django form?

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Ned Batchelder
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    3) Determine which form is submitted from field names in POST data. Include some hidden inputs if your froms don't have unique fields with all possible values being not empty. – Denis Otkidach Oct 24 '09 at 16:39
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    4) Add a hidden field identifying the form and check the value of this field in your view. – Soviut Jun 14 '11 at 03:40
  • I would stay away from polluting the POST data if possible. I recommend adding a GET parameter to the form action url instead. – pygeek Jul 29 '13 at 17:28
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    #1 is really your best bet here. You don't want to pollute you POST with hidden fields and nor do you want to tether your view to your template and/or form. – meteorainer Dec 17 '13 at 00:15
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    @meteorainer if you use number one, is there a way to pass the errors back to the forms in the parent view that instantiates these, without using either the messages framework or query strings? This answer seems the closest, but here it's still just one view handling both forms: http://stackoverflow.com/a/21271659/2532070 – YPCrumble Oct 15 '14 at 10:10
  • @YPCrumble using data attributes on the html elements could help solve some of these problems. The attributes can be used to identify the forms being posted. I mean, you can do the same thing with some identifier on the button, but with a data attribute on each form identifying them, you can have your view pass back the erring form, use js to replace the form on page with the erring form response, matching them up using the data attrs. I mean, if you're okay introducing ajax for this. – Jmichelsen Apr 23 '16 at 19:16
51

A method for future reference is something like this. bannedphraseform is the first form and expectedphraseform is the second. If the first one is hit, the second one is skipped (which is a reasonable assumption in this case):

if request.method == 'POST':
    bannedphraseform = BannedPhraseForm(request.POST, prefix='banned')
    if bannedphraseform.is_valid():
        bannedphraseform.save()
else:
    bannedphraseform = BannedPhraseForm(prefix='banned')

if request.method == 'POST' and not bannedphraseform.is_valid():
    expectedphraseform = ExpectedPhraseForm(request.POST, prefix='expected')
    bannedphraseform = BannedPhraseForm(prefix='banned')
    if expectedphraseform.is_valid():
        expectedphraseform.save()

else:
    expectedphraseform = ExpectedPhraseForm(prefix='expected')
Adam Nelson
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    using prefix= is indeed the 'proper way' – Rich Jul 18 '12 at 05:30
  • prefix-kwarg did the job, nice! – Stephan Hoyer Jan 07 '13 at 14:08
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    Great idea with those prefixes, we used those now and they work like a charm. But we still had to insert a hidden field to detect which form was submitted, because both forms are in a lightbox (each in a separate one). Because we need to reopen the correct lightbox we need to know exactly which form was submitted, and then if the first form has any validation errors, the second automatically wins and the first form is reset, although we still need to display the errors from the first form. Just thought you should know – Enduriel May 03 '13 at 16:12
  • Wouldn’t it be clunky to extend this pattern to the case of three forms? Like, with checking is_valid() from the first form, then the first two, etc… Maybe just have a `handled = False` that gets updated to `True` when a compatible form is found? – binki Jan 13 '16 at 22:31
19

I needed multiple forms that are independently validated on the same page. The key concepts I was missing were 1) using the form prefix for the submit button name and 2) an unbounded form does not trigger validation. If it helps anyone else, here is my simplified example of two forms AForm and BForm using TemplateView based on the answers by @adam-nelson and @daniel-sokolowski and comment by @zeraien (https://stackoverflow.com/a/17303480/2680349):

# views.py
def _get_form(request, formcls, prefix):
    data = request.POST if prefix in request.POST else None
    return formcls(data, prefix=prefix)

class MyView(TemplateView):
    template_name = 'mytemplate.html'

    def get(self, request, *args, **kwargs):
        return self.render_to_response({'aform': AForm(prefix='aform_pre'), 'bform': BForm(prefix='bform_pre')})

    def post(self, request, *args, **kwargs):
        aform = _get_form(request, AForm, 'aform_pre')
        bform = _get_form(request, BForm, 'bform_pre')
        if aform.is_bound and aform.is_valid():
            # Process aform and render response
        elif bform.is_bound and bform.is_valid():
            # Process bform and render response
        return self.render_to_response({'aform': aform, 'bform': bform})

# mytemplate.html
<form action="" method="post">
    {% csrf_token %}
    {{ aform.as_p }}
    <input type="submit" name="{{aform.prefix}}" value="Submit" />
    {{ bform.as_p }}
    <input type="submit" name="{{bform.prefix}}" value="Submit" />
</form>
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ybendana
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    I think this is actually a clean solution. Thanks. – chhantyal Jan 28 '16 at 13:12
  • I really like this solution. One question: is there a reason why _get_form() isn't a method of the MyView class? – airstrike Aug 17 '16 at 04:13
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    @AndréTerra it definitely could be, although you'd probably want to have it in a generic class that inherits from TemplateView so you can reuse it in other views. – ybendana Aug 17 '16 at 17:48
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    This is a great solution. I needed to change one line of the __get_form so that it would work: `data = request.POST if prefix in next(iter(request.POST.keys())) else None` Otherwise `in` didn't work. – larapsodia Aug 27 '16 at 16:27
  • Using a single
    tag like this means required fields are required globally when they should be per-form depending on which submit button was clicked. Splitting into two
    tags (with the same action) works.
    – Flash Nov 21 '17 at 13:45
15

Django's class based views provide a generic FormView but for all intents and purposes it is designed to only handle one form.

One way to handle multiple forms with same target action url using Django's generic views is to extend the 'TemplateView' as shown below; I use this approach often enough that I have made it into an Eclipse IDE template.

class NegotiationGroupMultifacetedView(TemplateView):
    ### TemplateResponseMixin
    template_name = 'offers/offer_detail.html'

    ### ContextMixin 
    def get_context_data(self, **kwargs):
        """ Adds extra content to our template """
        context = super(NegotiationGroupDetailView, self).get_context_data(**kwargs)

        ...

        context['negotiation_bid_form'] = NegotiationBidForm(
            prefix='NegotiationBidForm', 
            ...
            # Multiple 'submit' button paths should be handled in form's .save()/clean()
            data = self.request.POST if bool(set(['NegotiationBidForm-submit-counter-bid',
                                              'NegotiationBidForm-submit-approve-bid',
                                              'NegotiationBidForm-submit-decline-further-bids']).intersection(
                                                    self.request.POST)) else None,
            )
        context['offer_attachment_form'] = NegotiationAttachmentForm(
            prefix='NegotiationAttachment', 
            ...
            data = self.request.POST if 'NegotiationAttachment-submit' in self.request.POST else None,
            files = self.request.FILES if 'NegotiationAttachment-submit' in self.request.POST else None
            )
        context['offer_contact_form'] = NegotiationContactForm()
        return context

    ### NegotiationGroupDetailView 
    def post(self, request, *args, **kwargs):
        context = self.get_context_data(**kwargs)

        if context['negotiation_bid_form'].is_valid():
            instance = context['negotiation_bid_form'].save()
            messages.success(request, 'Your offer bid #{0} has been submitted.'.format(instance.pk))
        elif context['offer_attachment_form'].is_valid():
            instance = context['offer_attachment_form'].save()
            messages.success(request, 'Your offer attachment #{0} has been submitted.'.format(instance.pk))
                # advise of any errors

        else 
            messages.error('Error(s) encountered during form processing, please review below and re-submit')

        return self.render_to_response(context)

The html template is to the following effect:

...

<form id='offer_negotiation_form' class="content-form" action='./' enctype="multipart/form-data" method="post" accept-charset="utf-8">
    {% csrf_token %}
    {{ negotiation_bid_form.as_p }}
    ...
    <input type="submit" name="{{ negotiation_bid_form.prefix }}-submit-counter-bid" 
    title="Submit a counter bid"
    value="Counter Bid" />
</form>

...

<form id='offer-attachment-form' class="content-form" action='./' enctype="multipart/form-data" method="post" accept-charset="utf-8">
    {% csrf_token %}
    {{ offer_attachment_form.as_p }}

    <input name="{{ offer_attachment_form.prefix }}-submit" type="submit" value="Submit" />
</form>

...
Daniel Sokolowski
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    I am struggling with this same problem and was trying to find a way to process each post in a separate form view and then redirect to a common template view. The point is to make the template view responsible for the get content and the form views for the saving. validation is a problem though. saving the forms to the session crossed my mind... Still looking for a clean solution. – Daniele Bernardini Jul 18 '14 at 16:58
10

Wanted to share my solution where Django Forms are not being used. I have multiple form elements on a single page and I want to use a single view to manage all the POST requests from all the forms.

What I've done is I have introduced an invisible input tag so that I can pass a parameter to the views to check which form has been submitted.

<form method="post" id="formOne">
    {% csrf_token %}
   <input type="hidden" name="form_type" value="formOne">

    .....
</form>

.....

<form method="post" id="formTwo">
    {% csrf_token %}
    <input type="hidden" name="form_type" value="formTwo">
   ....
</form>

views.py

def handlemultipleforms(request, template="handle/multiple_forms.html"):
    """
    Handle Multiple <form></form> elements
    """
    if request.method == 'POST':
        if request.POST.get("form_type") == 'formOne':
            #Handle Elements from first Form
        elif request.POST.get("form_type") == 'formTwo':
            #Handle Elements from second Form
chatuur
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4

This is a bit late, but this is the best solution I found. You make a look-up dictionary for the form name and its class, you also have to add an attribute to identify the form, and in your views you have to add it as a hidden field, with the form.formlabel.

# form holder
form_holder = {
    'majeur': {
        'class': FormClass1,
    },
    'majsoft': {
        'class': FormClass2,
    },
    'tiers1': {
        'class': FormClass3,
    },
    'tiers2': {
        'class': FormClass4,
    },
    'tiers3': {
        'class': FormClass5,
    },
    'tiers4': {
        'class': FormClass6,
    },
}

for key in form_holder.keys():
    # If the key is the same as the formlabel, we should use the posted data
    if request.POST.get('formlabel', None) == key:
        # Get the form and initate it with the sent data
        form = form_holder.get(key).get('class')(
            data=request.POST
        )

        # Validate the form
        if form.is_valid():
            # Correct data entries
            messages.info(request, _(u"Configuration validée."))

            if form.save():
                # Save succeeded
                messages.success(
                    request,
                    _(u"Données enregistrées avec succès.")
                )
            else:
                # Save failed
                messages.warning(
                    request,
                    _(u"Un problème est survenu pendant l'enregistrement "
                      u"des données, merci de réessayer plus tard.")
                )
        else:
            # Form is not valid, show feedback to the user
            messages.error(
                request,
                _(u"Merci de corriger les erreurs suivantes.")
            )
    else:
        # Just initiate the form without data
        form = form_holder.get(key).get('class')(key)()

    # Add the attribute for the name
    setattr(form, 'formlabel', key)

    # Append it to the tempalte variable that will hold all the forms
    forms.append(form)

I hope this will help in the future.

e-nouri
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3

view:

class AddProductView(generic.TemplateView):
template_name = 'manager/add_product.html'

    def get(self, request, *args, **kwargs):
    form = ProductForm(self.request.GET or None, prefix="sch")
    sub_form = ImageForm(self.request.GET or None, prefix="loc")
    context = super(AddProductView, self).get_context_data(**kwargs)
    context['form'] = form
    context['sub_form'] = sub_form
    return self.render_to_response(context)

def post(self, request, *args, **kwargs):
    form = ProductForm(request.POST,  prefix="sch")
    sub_form = ImageForm(request.POST, prefix="loc")
    ...

template:

{% block container %}
<div class="container">
    <br/>
    <form action="{% url 'manager:add_product' %}" method="post">
        {% csrf_token %}
        {{ form.as_p }}
        {{ sub_form.as_p }}
        <p>
            <button type="submit">Submit</button>
        </p>
    </form>
</div>
{% endblock %}
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    Could you please explain your answer? It would help others with a simmilar problem and could help debugging your or the questioners code... – creyD Jan 09 '18 at 09:33
2

If you are using approach with class-based views and different 'action' attrs i mean

Put different URLs in the action for the two forms. Then you'll have two different view functions to deal with the two different forms.

You can easily handle errors from different forms using overloaded get_context_data method, e.x:

views.py:

class LoginView(FormView):
    form_class = AuthFormEdited
    success_url = '/'
    template_name = 'main/index.html'

    def dispatch(self, request, *args, **kwargs):
        return super(LoginView, self).dispatch(request, *args, **kwargs)

    ....

    def get_context_data(self, **kwargs):
        context = super(LoginView, self).get_context_data(**kwargs)
        context['login_view_in_action'] = True
        return context

class SignInView(FormView):
    form_class = SignInForm
    success_url = '/'
    template_name = 'main/index.html'

    def dispatch(self, request, *args, **kwargs):
        return super(SignInView, self).dispatch(request, *args, **kwargs)

    .....

    def get_context_data(self, **kwargs):
        context = super(SignInView, self).get_context_data(**kwargs)
        context['login_view_in_action'] = False
        return context

template:

<div class="login-form">
<form action="/login/" method="post" role="form">
    {% csrf_token %}
    {% if login_view_in_action %}
        {% for e in form.non_field_errors %}
            <div class="alert alert-danger alert-dismissable">
                {{ e }}
                <a class="panel-close close" data-dismiss="alert">×</a>
            </div>
        {% endfor %}
    {% endif %}
    .....
    </form>
</div>

<div class="signin-form">
<form action="/registration/" method="post" role="form">
    {% csrf_token %}
    {% if not login_view_in_action %}
        {% for e in form.non_field_errors %}
            <div class="alert alert-danger alert-dismissable">
                {{ e }}
                <a class="panel-close close" data-dismiss="alert">×</a>
            </div>
        {% endfor %}
    {% endif %}
   ....
  </form>
</div>
NameError
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Based on this answer by @ybendana:

Again, we use is_bound to check if the form is capable of validation. See this section of the documentation:

Bound and unbound forms

A Form instance is either bound to a set of data, or unbound.

  • If it’s bound to a set of data, it’s capable of validating that data and rendering the form as HTML with the data displayed in the HTML.
  • If it’s unbound, it cannot do validation (because there’s no data to validate!), but it can still render the blank form as HTML.

We use a list of tuples for form objects and their details allowing for more extensibility and less repetition.

However, instead of overriding get(), we override get_context_data() to make inserting a new, blank instance of the form (with prefix) into the response the default action for any request. In the context of a POST request, we override the post() method to:

  1. Use the prefix to check if each form has been submitted
  2. Validate the forms that have been submitted
  3. Process the valid forms using the cleaned_data
  4. Return any invalid forms to the response by overwriting the context data
# views.py

class MultipleForms(TemplateResponseMixin, ContextMixin, View):

    form_list = [ # (context_key, formcls, prefix)
        ("form_a", FormA, "prefix_a"),
        ("form_b", FormB, "prefix_b"),
        ("form_c", FormC, "prefix_c"),
        ...
        ("form_x", FormX, "prefix_x"),
    ]

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        # Add blank forms to context with prefixes
        for context_key, formcls, prefix in self.form_list:
            context[context_key] = formcls(prefix=prefix)
        return context

    def post(self, request, *args, **kwargs):
        # Get object and context
        self.object = self.get_object()
        context = self.get_context_data(object=self.object)
        # Process forms
        for context_key, formcls, prefix in self.form_list:
            if prefix in request.POST:
                # Get the form object with prefix and pass it the POST data to \
                # validate and clean etc.
                form = formcls(request.POST, prefix=prefix)
                if form.is_bound:
                    # If the form is bound (i.e. it is capable of validation)  \
                    # check the validation
                    if form.is_valid():
                        # call the form's save() method or do whatever you     \
                        # want with form.cleaned_data
                        form.save()
                    else:
                        # overwrite context data for this form so that it is   \
                        # returned to the page with validation errors
                        context[context_key] = form
        # Pass context back to render_to_response() including any invalid forms
        return self.render_to_response(context)
        

This method allows repeated form entries on the same page, something I found did not work with @ybendana's answer.

I believe it wouldn't be masses more work to fold this method into a Mixin class, taking the form_list object as an attribute and hooking get_context_data() and post() as above.

Edit: This already exists. See this repository.

NB: This method required TemplateResponseMixin for render_to_response() and ContextMixin for get_context_data() to work. Either use these Mixins or a CBV that descends from them.

xle
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0

Here is simple way to handle the above.

In Html Template we put Post

<form action="/useradd/addnewroute/" method="post" id="login-form">{% csrf_token %}

<!-- add details of form here-->
<form>
<form action="/useradd/addarea/" method="post" id="login-form">{% csrf_token %}

<!-- add details of form here-->

<form>

In View

   def addnewroute(request):
      if request.method == "POST":
         # do something



  def addarea(request):
      if request.method == "POST":
         # do something

In URL Give needed info like

urlpatterns = patterns('',
url(r'^addnewroute/$', views.addnewroute, name='addnewroute'),
url(r'^addarea/', include('usermodules.urls')),
Abilash Raghu
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if request.method == 'POST':
    expectedphraseform = ExpectedphraseForm(request.POST)
    bannedphraseform = BannedphraseForm(request.POST)
    if expectedphraseform.is_valid():
        expectedphraseform.save()
        return HttpResponse("Success")
    if bannedphraseform.is_valid():
        bannedphraseform.save()
        return HttpResponse("Success")
else:
    bannedphraseform = BannedphraseForm()
    expectedphraseform = ExpectedphraseForm()
return render(request, 'some.html',{'bannedphraseform':bannedphraseform, 'expectedphraseform':expectedphraseform})

This worked for me accurately as I wanted. This Approach has a single problem that it validates both the form's errors. But works Totally fine.

atomvs
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I discovered a pretty interesting way to send TWO Forms from a single page using the same view. I tried many options but just wanted something that can just work. So here is something that I discovered. But it only works when there are just TWO Forms on a page.

I am using just try and except method to first try first form and if that doesnt works than try second form. This is quiet interesting to know that it works absolutely fine. Don't use it on scalable application as it can create troublesome or may risk the security of the application, else use Class based view to submit mutiple forms or create seperate views for each form.

def create_profile(request):
    if request.method=='POST':
        try:       
            biograph = Biography(name=name, email=email, full_name=full_name, slug_name=slug_name, short_bio=short_bio)
            biograph.save()

        except:
            social = SocialMedia(twitter=twitter, instagram=instagram, facebook=facebook, linkedin=linkedin, github=github)
            social.save()
Abdul Rehman
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