CODEWITHSUNDEEP
regexdjangoformsvalidation
user1807271
user1807271

Reputation: 1006

Django: Checking CharField format in form with a regular expression

class CapaForm(forms.Form):
    capa = forms.CharField(required=False)

Upon form submission I want to check the format of the capa field. I want to require the user to enter the capa format correctly as 6 numbers, a dash, and two numbers. (######-##)

def search(self):
    capa = self.cleaned_data.get('capa', None)

    if ("\d{6}\-\d{2}" or None) not in capa:
            raise forms.ValidationError("CAPA format needs to be ######-##!")

It's currently not letting me submit a correctly formatted capa and throws the ValidationError. I think the problem is I'm trying to compare a regular expression to an object. How can I check the format of the 'capa' the user tries to submit?

*********UPDATE

Everything is working now EXCEPT when I type the wrong format in the CAPA field. I get the error The view incidents.views.index didn't return an HttpResponse object. It returned None instead. Is this related to the changes I made?

from django.core.validators import RegexValidator
my_validator = RegexValidator("\d{6}\-\d{2}", "CAPA format needs to be ######-##.")

class CapaForm(forms.Form):
    capa = forms.CharField(
        label="CAPA",
        required=False, # Note: validators are not run against empty fields
        validators=[my_validator]
        )

def search(self):
    capa = self.cleaned_data.get('capa', None)
    query = Incident.objects.all()
    if capa is not '':
            query = query.filter(capa=capa)
    return(query)

Upvotes: 13

Views: 16860

Answers (4)

smrf
smrf

Reputation: 361

Regex validator does not work for me in Django 2.2

Step to set up custom validation for a field value:

  1. define the validation function:

    def number_code_validator(value):
    if not re.compile(r'^\d{10}$').match(value):
        raise ValidationError('Enter Number Correctly')

  2. In the form add the defined function to validators array of the field:

    number= forms.CharField(label="Number", 
                        widget=TextInput(attrs={'type': 'number'}),
                        validators=[number_code_validator])

Upvotes: 1

Art
Art

Reputation: 2335

First you need a regex validator: Django validators / regex validator

Then, add it into the validator list of your field: using validators in forms

Simple example below:

from django.core.validators import RegexValidator
my_validator = RegexValidator(r"A", "Your string should contain letter A in it.")

class MyForm(forms.Form):

    subject = forms.CharField(
        label="Test field",
        required=True,  # Note: validators are not run against empty fields
        validators=[my_validator]
    )

Upvotes: 25

tvorog
tvorog

Reputation: 1129

You can also use RegexField. It's the same as CharField but with additional argument regex. Under the hood it uses validators.

Example:

class MyForm(forms.Form):
    field1 = forms.RegexField(regex=re.compile(r'\d{6}\-\d{2}'))

Upvotes: 1

romainm
romainm

Reputation: 281

you could also ask from both part in your form, it would be cleaner for the user :

class CapaForm(forms.Form):
capa1 = forms.IntegerField(max_value=9999, required=False)
capa2 = forms.IntegerField(max_value=99, required=False)

and then just join them in your view :

capa = self.cleaned_data.get('capa1', None) + '-' + self.cleaned_data.get('capa2', None)

Upvotes: 1

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