Overloading Django Form Fields

less magic:

     from django.db import models
    +from django.core.exceptions import ValidationError
     
    +def not_empty(value):
    +    if value == u'': raise ValidationError(u'Empty value')
     
     class MyModel(models.Model):
    -    name = models.CharField(max_length=50, blank=True)
    +    name = models.CharField(max_length=50, blank=True, validators=[not_empty])

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Knowing how to change form field attributes in the __init__ method is very useful, but I wouldn't call it "overloading"[1][2].

[1] http://en.wikipedia.org/wiki/Function_overloading

[2] http://en.wikipedia.org/wiki/Operator_overloading

Yes. A thousand times yes. I think the reason more people don't do it this way is because the documentation emphasizes how declarative models, forms, admin classes, etc are, and people forget that it's all just Python.

I've had much more luck with WTForms than django forms. Specifically, the FormField method for decomposing common elements of multiple forms is much more pleasant to work with than trying to do something in Django.

This looks nice for when the fields in a form and model are identical, but in my experience that doesn't happen all that often.

For those wondering about 'the second bug', I'm going to suggest that it's the lack of

    class Meta:
        fields = ('only', 'whitelisted', 'fields')

which defaults the form to exposing all the model fields for modification, allowing naughtyness not unlike the Rails mass-assignment issues that cropped up a while back.

Or maybe the name field having blank=True, but no default value?

Hey, I bought your book but I'm not sure I have the link to the latest version. The last version I had a link to was "tsd20130326.pdf" - is that the latest?

He-he. Exactly the same I did when I encountered this problem. :)