Django: form validation: accepting multiple values for one field - django

Question

I'm looking to create a form field that takes multiple values for a given field, validates them, and stores them as a list.
For example, one can run the following curl command and post several POST parameters called 'email'
curl -X POST -d email=test#example.com -d email=test2#example.com http://url/here/
In my view, I can execute the following to get a list of emails directly from the POST data.
email = request.POST.getlist('email')
However, I'd like to take advantage of form validation to clean all of the emails specified in the POST data.
Ideally, I'd like to run form.is_valid() and then access the the cleaned_data['email'] key on the form would return a list of valid email addresses.
I've looked into using MultipleChoice fields, and similar fields (because they accept multiple inputs with the same name), but those fields require that you define the choices beforehand. I've also considered using formsets, but those seem overly-complicated for what I'm trying to do in this case.
Does anyone know of any fields that behave in this way? Thanks for reading.

Answer 1

I'm looking for something similar and I found this: http://djangosnippets.org/snippets/497/
from django import newforms as forms
class SeparatedValuesField(forms.Field):
"""
A Django newforms field which takes another newforms field during
initialization and validates every item in a separated list with
this field class. Please use it like this::
from django.newforms import EmailField
emails = SeparatedValuesField(EmailField)
You would be able to enter a string like 'john#doe.com,guido#python.org'
because every email address would be validated when clean() is executed.
This of course also applies to any other Field class.
You can define the sepator (default: ',') during initialization with the
``separator`` parameter like this::
from django.newforms import EmailField
emails = SeparatedValuesField(EmailField, separator='###')
If validation succeeds it returns the original data, though the already
splitted value list can be accessed with the get_list() method.
>>> f = SeparatedValuesField(forms.EmailField)
>>> f.clean('foo#bar.com,bar#foo.com')
'foo#bar.com,bar#foo.com'
>>> f.get_list()
['foo#bar.com', 'bar#foo.com']
>>> f.clean('foobar,foo#bar.com,bar#foo.com')
Traceback (most recent call last):
...
ValidationError: <unprintable ValidationError object>
>>> u = SeparatedValuesField(forms.URLField)
>>> u.clean('http://foo.bar.com,http://foobar.com')
'http://foo.bar.com,http://foobar.com'
>>> u.clean('http:foo.bar.com')
Traceback (most recent call last):
...
ValidationError: <unprintable ValidationError object>
>>> f = SeparatedValuesField(forms.EmailField, separator='###')
>>> f.clean('foo#bar.com###bar#foo.com')
'foo#bar.com###bar#foo.com'
>>> f.clean('foobar###foo#bar.com###bar#foo.com')
Traceback (most recent call last):
...
ValidationError: <unprintable ValidationError object>
"""
def __init__(self, base_field=None, separator=',', *args, **kwargs):
super(SeparatedValuesField, self).__init__(*args, **kwargs)
self.base_field = base_field
self.separator = separator
def clean(self, data):
if not data:
raise forms.ValidationError('Enter at least one value.')
self.value_list = data.split(self.separator)
if self.base_field is not None:
base_field = self.base_field()
for value in self.value_list:
base_field.clean(value)
return data
def get_list(self):
return self.value_list
def _test():
import doctest
doctest.testmod()
if __name__ == "__main__":
_test()
It's not totally satisfactory though: for a list of emails for example, if only one email is not valid, the whole field is not valid.
One could probably rewrite the clean method so that it returns only the valid 'base_fields' instead of throwing a ValidationError altogether.

Answer 2

In 2018, there was still no satisfactory answer to this question, so I wrote my own field which behaves like the OP wanted. Check it out here.
To solve the original problem:
forms.py:
import django.forms as forms
from multivaluefield import MultiValueField
class MultiEmailForm(forms.Form):
emails = MultiValueField(forms.EmailField(), "email")
View code:
form = MultiEmailForm(request.POST)
if form.is_valid:
emails = form.cleaned_data["emails"]
# do something with emails
else:
errors = form.errors
# do something with errors

Answer 3

django-multi-email-field can do this: https://github.com/fle/django-multi-email-field
Sample form code:
from django import forms
from multi_email_field.forms import MultiEmailField
class SendMessageForm(forms.Form):
emails = MultiEmailField()
Sample view code:
assert form.is_valid()
print(form.cleaned_data["emails"])