Added deprecation warning to NLBankAccountNumberField (#307)

Ref: #150

docs/changelog.rst

@@ -23,6 +23,8 @@ Modifications to existing flavors:
   (`gh-305 <https://github.com/django/django-localflavor/pull/305>`_).
 - Added support for Swedish interim personal identity numbers
   (`gh-308 <https://github.com/django/django-localflavor/pull/308>`_).
+- Deprecated `nl.models.NLBankAccountNumberField`.
+  (`gh-307 <https://github.com/django/django-localflavor/pull/307>`_).
 
 Other changes:
 

localflavor/nl/models.py

@@ -121,9 +121,20 @@ class NLBankAccountNumberField(models.CharField):
     This model field uses :class:`validators.NLBankAccountNumberFieldValidator` for validation.
 
     .. versionadded:: 1.1
+
+    .. deprecated:: 1.6
+        Use `localflavor.generic.models.IBANField` with included_countries=('nl') option instead.
+        Note that a data migration is required to move the data from this field to a new IBANField:
+        it needs to calculate check digits, add the bank identifier and zero-pad the bank number
+        into a proper IBAN.
     """
 
     def __init__(self, *args, **kwargs):
+        self.system_check_deprecated_details = {
+            'msg': self.__class__.__name__ + ' is deprecated.',
+            'hint': "Use `localflavor.generic.models.IBANField` with included_countries=('nl') option instead."
+        }
+
         kwargs.setdefault('max_length', 10)
         super(NLBankAccountNumberField, self).__init__(*args, **kwargs)
         # Ensure that only the NLBankAccountNumberFieldValidator is set.