Tastypie ModelForm validation that only validates submitted fields on PUT requests

forms.py

from tastypie.validation import CleanedDataFormValidation


def pick(d, keys):
    """Based on http://underscorejs.org/#pick"""
    return dict((key, val) for key, val in d.items() if key in keys)


class BaseFormValidation(CleanedDataFormValidation):
    """
    Validation logic to use for all resources

    We ignore errors and cleaned_data on PUT requests for fields not sent

    This also implements https://github.com/toastdriven/django-tastypie/issues/152
    """
    def is_valid(self, bundle, request=None):
        data = bundle.data or {}
        submitted_fields = data.keys()
        form = self.form_class(data)

        if form.is_valid():
            # For PUT requests, only select cleaned_data for submitted fields
            if request and request.method is 'PUT':
                bundle.data = pick(form.cleaned_data, submitted_fields)
            else:
                bundle.data = form.cleaned_data
            return {}

        # For PUT requests, only select errors for submitted fields
        errors = form.errors
        if request and request.method is 'PUT':
            errors = pick(form.errors, submitted_fields)
        
        return errors






# usage
from tastypie.resources import ModelResource
from .forms import MyModelForm

class MyResource(ModelResource):
    class Meta:
        validation = BaseFormValidation(form_class=MyModelForm)