__init__.py

# All this craziness is so that we can allow the classes in nested_admin.formsets
# to be importable directly from this module, e.g.:
#
#     from nested_admin import NestedInlineFormSet
#
# without running afoul of the strict import order required by Django 1.9+.
# This implementation is shamelessly stolen from werkzeug's ``__init__.py``.
#
# Also included is a monkey-patch for django.forms.formsets.all_valid().
import sys
from types import ModuleType

import django
import django.forms.formsets
import monkeybiz

__version__ = "4.0.0"

# import mapping to objects in other modules
all_by_module = {
    "nested_admin.forms": ("SortableHiddenMixin",),
    "nested_admin.formsets": ("NestedInlineFormSet", "NestedBaseGenericInlineFormSet"),
    "nested_admin.nested": (
        "NestedModelAdmin",
        "NestedModelAdminMixin",
        "NestedInlineAdminFormset",
        "NestedInlineModelAdmin",
        "NestedStackedInline",
        "NestedTabularInline",
        "NestedInlineModelAdminMixin",
        "NestedGenericInlineModelAdmin",
        "NestedGenericStackedInline",
        "NestedGenericTabularInline",
        "NestedStackedInlineMixin",
        "NestedTabularInlineMixin",
        "NestedGenericStackedInline",
        "NestedGenericTabularInline",
        "NestedGenericStackedInlineMixin",
        "NestedGenericTabularInlineMixin",
        "NestedGenericInlineModelAdminMixin",
        "NestedInlineAdminFormsetMixin",
    ),
}

all_by_module["nested_admin.polymorphic"] = (
    "NestedPolymorphicInlineAdminFormset",
    "NestedPolymorphicInlineModelAdmin",
    "NestedStackedPolymorphicInline",
    "NestedPolymorphicInlineSupportMixin",
    "NestedPolymorphicModelAdmin",
    "NestedGenericPolymorphicInlineModelAdmin",
    "NestedGenericStackedPolymorphicInline",
)

# modules that should be imported when accessed as attributes of nested_admin
attribute_modules = frozenset(["forms", "formsets", "nested", "polymorphic"])

object_origins = {}
for module, items in all_by_module.items():
    for item in items:
        object_origins[item] = module


class module(ModuleType):
    def __dir__(self):
        """Just show what we want to show."""
        result = list(new_module.__all__)
        result.extend(
            (
                "__file__",
                "__path__",
                "__doc__",
                "__all__",
                "__docformat__",
                "__name__",
                "__path__",
                "__package__",
                "__version__",
            )
        )
        return result

    def __getattr__(self, name):
        if name in object_origins:
            module = __import__(object_origins[name], None, None, [name])
            for extra_name in all_by_module[module.__name__]:
                setattr(self, extra_name, getattr(module, extra_name))
            return getattr(module, name)
        elif name in attribute_modules:
            __import__("nested_admin." + name)
        return ModuleType.__getattribute__(self, name)


# keep a reference to this module so that it's not garbage collected
old_module = sys.modules[__name__]

# setup the new module and patch it into the dict of loaded modules
new_module = sys.modules[__name__] = module(__name__)
new_module.__dict__.update(
    {
        "__file__": __file__,
        "__package__": "nested_admin",
        "__path__": __path__,
        "__doc__": __doc__,
        "__version__": __version__,
        "__all__": tuple(object_origins) + tuple(attribute_modules),
        "__docformat__": "restructuredtext en",
    }
)

all_valid_patch_modules = [django.forms.formsets]

# If django.contrib.admin.options has already been imported, we'll need to
# monkeypatch all_valid in that module as well
admin_module = sys.modules.get("django.contrib.admin.options")
if admin_module:
    all_valid_patch_modules.append(admin_module)


def descend_form(form):
    for formset in getattr(form, "nested_formsets", None) or []:
        yield from descend_formset(formset)


def descend_formset(formset):
    for form in formset:
        yield (formset, form)
        yield from descend_form(form)


def patch_delete_children_empty_permitted(formsets):
    """Set empty_permitted=True for descendent forms of forms that are to be deleted"""
    for top_level_formset in formsets:
        for formset, form in descend_formset(top_level_formset):
            formset._errors = None
            form._errors = None
            if formset.can_delete and formset._should_delete_form(form):
                for _, child_form in descend_form(form):
                    child_form.empty_permitted = True


@monkeybiz.patch(all_valid_patch_modules)
def all_valid(original_all_valid, formsets):
    """
    Checks validation on formsets, then handles a case where an inline
    has new data but one of its parent forms is blank.

    This causes a bug when one of the parent forms has empty_permitted == True,
    which happens if it is an "extra" form in the formset and its index
    is >= the formset's min_num.

    Also hooks into the original validation to suppress validation errors thrown
    by descendent inlines of deleted forms.
    """
    if not original_all_valid(formsets):
        if len(formsets) and getattr(formsets[0], "data", None):
            has_delete = any(k for k in formsets[0].data if k.endswith("-DELETE"))
            if has_delete:
                patch_delete_children_empty_permitted(formsets)
                return original_all_valid(formsets)
        return False

    for formset in formsets:
        if formset.has_changed() and getattr(formset, "parent_form", None):
            parent_form = formset.parent_form

            while True:
                if parent_form.empty_permitted:
                    parent_form.empty_permitted = False
                    # Reset the validation errors
                    parent_form._errors = None
                    if not parent_form.instance.pk and not parent_form.has_changed():
                        # Force Django to try to save the instance,
                        # since we need it for the fk to work
                        changed_data = parent_form.fields.keys()
                        parent_form.__dict__["changed_data"] = changed_data
                if not hasattr(parent_form, "parent_formset"):
                    break
                parent_form.parent_formset._errors = None
                if not hasattr(parent_form.parent_formset, "parent_form"):
                    break
                parent_form = parent_form.parent_formset.parent_form

    if not original_all_valid(formsets):
        return False

    return True