CODEWITHSUNDEEP
djangodjango-forms
Darwin Tech
Darwin Tech

Reputation: 18929

Django custom validation of multiple fields in a form

for which I want to validate a number of fields in a custom clean method.

I have this so far:

class ProjectInfoForm(forms.Form):
    module = forms.ModelChoiceField(
        queryset=Module.objects.all(),
    )
    piece = forms.CharField(
        widget=forms.Select(),
        required=False,
    )
    span = forms.IntegerField(
        max_value=100,
        initial=48
    )
    max_span = forms.IntegerField(
        max_value=100,
        initial=0
    )


    def clean(self):
        span = self.cleaned_data['span']
        max_span = self.cleaned_data['max_span']
        piece = self.cleaned_data.['piece']

        # validate piece 
        try:
            Piece.objects.get(pk=m)
        except Piece.DoesNotExist:
            raise forms.ValidationError(
                'Illegal Piece selected!'
            )
            self._errors["piece"] = "Please enter a valid model"

        # validate spans
        if span > max_span:
            raise forms.ValidationError(
                'Span must be less than or equal to Maximum Span'
            )
            self._errors["span"] = "Please enter a valid span"
        return self.cleaned_data

However, this only gives me one of the messages if both clauses invalidate. How can I get all the invalid messages. Also I do not get the field-specific messages - how do I include a message to be displayed for the specific field?

Any help much appreciated.

Upvotes: 7

Views: 12525

Answers (4)

user535883
user535883

Reputation:

It appears this has changed in later versions of Django (this seems to work in 2.1 and later):


from django import forms

class ContactForm(forms.Form):
    # Everything as before.
    ...

    def clean(self):
        cleaned_data = super().clean()
        cc_myself = cleaned_data.get("cc_myself")
        subject = cleaned_data.get("subject")

        if cc_myself and subject and "help" not in subject:
            msg = "Must put 'help' in subject when cc'ing yourself."
            self.add_error('cc_myself', msg)
            self.add_error('subject', msg)

https://docs.djangoproject.com/en/dev/ref/forms/validation/#raising-multiple-errors has more details.

Upvotes: 0

XORcist
XORcist

Reputation: 4367

You should write a custom clean_FIELDNAME method in this case. That way, field centric validation errors can later be displayed as such when using {{form.errors}} in your template. The clean method o.t.h. is for validating logic that spans more than one field. Take a look through the link I posted above, everything you need to know about validating django forms is in there.

Upvotes: 1

anacarolinats
anacarolinats

Reputation: 667

It happens because you are using raise. Try replace it by these two line in your code:

del self.cleaned_data['piece']

and

del self.cleaned_data['span']

Upvotes: 0

mVChr
mVChr

Reputation: 50205

Store the errors and don't raise them until the end of the method:

def clean(self):
    span = self.cleaned_data['span']
    max_span = self.cleaned_data['max_span']
    piece = self.cleaned_data.['piece']
    error_messages = []

    # validate piece 
    try:
        Piece.objects.get(pk=m)
    except Piece.DoesNotExist:
        error_messages.append('Illegal Piece selected')
        self._errors["piece"] = "Please enter a valid model"

    # validate spans
    if span > max_span:
        error_messages.append('Span must be less than or equal to Maximum Span')
        self._errors["span"] = "Please enter a valid span"

    if len(error_messages):
        raise forms.ValidationError(' & '.join(error_messages))

    return self.cleaned_data

Upvotes: 8

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