Fixed #17642 -- Added min_num support to modelformsets, inlines, and the admin.

Thanks Stephen Burrows for work on the patch as well.

Forwardport of 2914f66983a92fcae55673c517dd8d01e8c238c4 from stable/1.7.x

5 files changed, 32 insertions, 9 deletions

diff --git a/django/contrib/admin/checks.py b/django/contrib/admin/checks.py
index dfe4cd04ec..e49bb8fb6e 100644
--- a/django/contrib/admin/checks.py
+++ b/django/contrib/admin/checks.py
@@ -850,6 +850,7 @@ class InlineModelAdminChecks(BaseModelAdminChecks):
         errors.extend(self._check_exclude_of_parent_model(cls, parent_model))
         errors.extend(self._check_extra(cls))
         errors.extend(self._check_max_num(cls))
+        errors.extend(self._check_min_num(cls))
         errors.extend(self._check_formset(cls))
         return errors
 
@@ -909,12 +910,22 @@ class InlineModelAdminChecks(BaseModelAdminChecks):
         else:
             return []
 
+    def _check_min_num(self, cls):
+        """ Check that min_num is an integer. """
+
+        if cls.min_num is None:
+            return []
+        elif not isinstance(cls.min_num, int):
+            return must_be('an integer', option='min_num', obj=cls, id='admin.E205')
+        else:
+            return []
+
     def _check_formset(self, cls):
         """ Check formset is a subclass of BaseModelFormSet. """
 
         if not issubclass(cls.formset, BaseModelFormSet):
             return must_inherit_from(parent='BaseModelFormSet', option='formset',
-                                     obj=cls, id='admin.E205')
+                                     obj=cls, id='admin.E206')
         else:
             return []
 
diff --git a/django/contrib/admin/options.py b/django/contrib/admin/options.py
index 016b73d987..2d5a5cf933 100644
--- a/django/contrib/admin/options.py
+++ b/django/contrib/admin/options.py
@@ -1706,6 +1706,7 @@ class InlineModelAdmin(BaseModelAdmin):
     fk_name = None
     formset = BaseInlineFormSet
     extra = 3
+    min_num = None
     max_num = None
     template = None
     verbose_name = None
@@ -1738,6 +1739,10 @@ class InlineModelAdmin(BaseModelAdmin):
         """Hook for customizing the number of extra inline forms."""
         return self.extra
 
+    def get_min_num(self, request, obj=None, **kwargs):
+        """Hook for customizing the min number of inline forms."""
+        return self.min_num
+
     def get_max_num(self, request, obj=None, **kwargs):
         """Hook for customizing the max number of extra inline forms."""
         return self.max_num
@@ -1769,6 +1774,7 @@ class InlineModelAdmin(BaseModelAdmin):
             "exclude": exclude,
             "formfield_callback": partial(self.formfield_for_dbfield, request=request),
             "extra": self.get_extra(request, obj, **kwargs),
+            "min_num": self.get_min_num(request, obj, **kwargs),
             "max_num": self.get_max_num(request, obj, **kwargs),
             "can_delete": can_delete,
         }
diff --git a/django/contrib/contenttypes/admin.py b/django/contrib/contenttypes/admin.py
index 8da6546a21..1938fa7aae 100644
--- a/django/contrib/contenttypes/admin.py
+++ b/django/contrib/contenttypes/admin.py
@@ -119,6 +119,7 @@ class GenericInlineModelAdmin(InlineModelAdmin):
             "can_delete": can_delete,
             "can_order": False,
             "fields": fields,
+            "min_num": self.min_num,
             "max_num": self.max_num,
             "exclude": exclude
         }
diff --git a/django/contrib/contenttypes/forms.py b/django/contrib/contenttypes/forms.py
index 33df7528db..693628d3de 100644
--- a/django/contrib/contenttypes/forms.py
+++ b/django/contrib/contenttypes/forms.py
@@ -56,9 +56,9 @@ def generic_inlineformset_factory(model, form=ModelForm,
                                   ct_field="content_type", fk_field="object_id",
                                   fields=None, exclude=None,
                                   extra=3, can_order=False, can_delete=True,
-                                  max_num=None,
-                                  formfield_callback=None, validate_max=False,
-                                  for_concrete_model=True):
+                                  max_num=None, formfield_callback=None,
+                                  validate_max=False, for_concrete_model=True,
+                                  min_num=None, validate_min=False):
     """
     Returns a ``GenericInlineFormSet`` for the given kwargs.
 
@@ -81,7 +81,8 @@ def generic_inlineformset_factory(model, form=ModelForm,
                                    formset=formset,
                                    extra=extra, can_delete=can_delete, can_order=can_order,
                                    fields=fields, exclude=exclude, max_num=max_num,
-                                   validate_max=validate_max)
+                                   validate_max=validate_max, min_num=min_num,
+                                   validate_min=validate_min)
     FormSet.ct_field = ct_field
     FormSet.ct_fk_field = fk_field
     FormSet.for_concrete_model = for_concrete_model
diff --git a/django/forms/models.py b/django/forms/models.py
index f1a383fde6..263d3d4340 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -805,7 +805,8 @@ def modelformset_factory(model, form=ModelForm, formfield_callback=None,
                          formset=BaseModelFormSet, extra=1, can_delete=False,
                          can_order=False, max_num=None, fields=None, exclude=None,
                          widgets=None, validate_max=False, localized_fields=None,
-                         labels=None, help_texts=None, error_messages=None):
+                         labels=None, help_texts=None, error_messages=None,
+                         min_num=None, validate_min=False):
     """
     Returns a FormSet class for the given Django model class.
     """
@@ -823,9 +824,9 @@ def modelformset_factory(model, form=ModelForm, formfield_callback=None,
                              formfield_callback=formfield_callback,
                              widgets=widgets, localized_fields=localized_fields,
                              labels=labels, help_texts=help_texts, error_messages=error_messages)
-    FormSet = formset_factory(form, formset, extra=extra, max_num=max_num,
+    FormSet = formset_factory(form, formset, extra=extra, min_num=min_num, max_num=max_num,
                               can_order=can_order, can_delete=can_delete,
-                              validate_max=validate_max)
+                              validate_min=validate_min, validate_max=validate_max)
     FormSet.model = model
     return FormSet
 
@@ -969,7 +970,8 @@ def inlineformset_factory(parent_model, model, form=ModelForm,
                           fields=None, exclude=None, extra=3, can_order=False,
                           can_delete=True, max_num=None, formfield_callback=None,
                           widgets=None, validate_max=False, localized_fields=None,
-                          labels=None, help_texts=None, error_messages=None):
+                          labels=None, help_texts=None, error_messages=None,
+                          min_num=None, validate_min=False):
     """
     Returns an ``InlineFormSet`` for the given kwargs.
 
@@ -989,8 +991,10 @@ def inlineformset_factory(parent_model, model, form=ModelForm,
         'can_order': can_order,
         'fields': fields,
         'exclude': exclude,
+        'min_num': min_num,
         'max_num': max_num,
         'widgets': widgets,
+        'validate_min': validate_min,
         'validate_max': validate_max,
         'localized_fields': localized_fields,
         'labels': labels,