Django: Catching Integrity Error and showing a customized message using template

Question

In my django powered app there is only one obvious case where \"IntegrityError\" can arise.
So, how can I catch that error and display a message using templates?

Answer 1

I would validate it with ModelForm. For example:

You got model:

class Manufacturer(models.Model):
    name = models.CharField(default='', max_length=40, unique=True)

And ModelForm:

class ManufacturerForm(forms.ModelForm):

    def clean(self):
        cleaned_data = super(ManufacturerForm, self).clean()
        name = cleaned_data.get('name')
        if Manufacturer.objects.filter(name=name).exists():
            raise forms.ValidationError('Category already exists')

    class Meta:
        model = Manufacturer

In this case when you submit name that is unique. You'll get validation error before IntegrityError. 'Category already exists' message will be shown in your form in template