Validation not running in django form - django

Question

I want to run field validatin on my form, as in form and field validation- using validation in practice.
My form looks like this:
from kapsule.validators import name_zero_min_length, name_max_length
class NameUpdateForm(forms.Form):
name = forms.CharField(
validators=[
name_zero_min_length,
name_max_length
]
)
My validators:
from django.core.exceptions import ValidationError
def name_zero_min_length(name_field):
# Check minimum length
if not len(name_field) > 0:
print('firing zero length')
raise ValidationError(
"My custom error message name must be at least one character"
)
def name_max_length(name_field):
# Check that the name is under the max length
MAX_LENGTH = 200
if len(name_field) > MAX_LENGTH:
print('raising')
raise ValidationError(
"My custom error message name cannot be more than {} characters".format(MAX_LENGTH)
)
My view like this:
def edit_kapsule_name(request, kapsule_pk):
kapsule = Kapsule.objects.get(pk=kapsule_pk)
form = NameUpdateForm(request.POST)
response = {}
print('pre-validation')
if form.is_valid():
print('VALID')
name = form.data.get('name')
kapsule.name = name
kapsule.save(update_fields=['name'])
else:
print('INVALID') # INVALID
print('json') # json
errors = form._errors.as_json()
print(errors) # {"name": [{"message": "This field is required.", "code": "required"}]}
My output is commented in the above code (invalid, and giving a different error that that which I expected).
Why is my custom validation not running?
This seems to match with my model validation (working), and the second reponse here

Answer 1

Well in the comment from your code I can see that the form is invalid and it is complaining about a required field. That might be the cause your validators are not running, according to the docs:
The clean() method on a Field subclass is responsible for running to_python(), validate(), and run_validators() in the correct order and propagating their errors. If, at any time, any of the methods raise ValidationError, the validation stops and that error is raised. This method returns the clean data, which is then inserted into the cleaned_data dictionary of the form.
On the other hand, if the field is required, the validation not len(name_field) > 0 has no much sense.
Try calling your validators as part of the clean_name method in your form.