reducing the need to use sync_to_async on model forms

django_async_extensions/aforms/models.py

@@ -4,8 +4,26 @@
 
 from django.forms.models import ModelForm
 
+from django_async_extensions.aforms.utils import AsyncRenderableFormMixin
+
+
+class AsyncModelForm(AsyncRenderableFormMixin, ModelForm):
+    @classmethod
+    async def from_async(cls, *args, **kwargs):
+        return await sync_to_async(cls)(*args, **kwargs)
+
+    @property
+    async def aerrors(self):
+        if self._errors is None:
+            await self.afull_clean()
+        return self._errors
+
+    async def ais_valid(self):
+        return self.is_bound and not await self.aerrors
+
+    async def afull_clean(self):
+        return await sync_to_async(self.full_clean)()
 
-class AsyncModelForm(ModelForm):
     async def _asave_m2m(self):
         """
         Save the many-to-many fields and generic relations for this form.

django_async_extensions/aforms/utils.py

@@ -0,0 +1,31 @@
+from asgiref.sync import sync_to_async
+
+from django.utils.safestring import mark_safe
+
+
+class AsyncRenderableMixin:
+    async def arender(self, template_name=None, context=None, renderer=None):
+        renderer = renderer or self.renderer
+        template = template_name or self.template_name
+        context = context or self.get_context()
+        return mark_safe(  # noqa:S308
+            await sync_to_async(renderer.render)(template, context)
+        )
+
+
+class AsyncRenderableFormMixin(AsyncRenderableMixin):
+    async def aas_p(self):
+        """Render as <p> elements."""
+        return await self.arender(self.template_name_p)
+
+    async def aas_table(self):
+        """Render as <tr> elements excluding the surrounding <table> tag."""
+        return await self.arender(self.template_name_table)
+
+    async def aas_ul(self):
+        """Render as <li> elements excluding the surrounding <ul> tag."""
+        return await self.arender(self.template_name_ul)
+
+    async def aas_div(self):
+        """Render as <div> elements."""
+        return await self.arender(self.template_name_div)

tests/test_model_forms/test_model_form.py

@@ -310,7 +310,7 @@ def __init__(self, *args, **kwargs):
         assert f1.is_valid()
 
         f2 = FormForTestingIsValid(data2)
-        assert await sync_to_async(f2.is_valid)()
+        assert await f2.ais_valid()
 
         obj = await f2.asave()
         assert obj.character == char
@@ -965,25 +965,25 @@ def setup(self):
 
     async def test_simple_unique(self):
         form = ProductForm({"slug": "teddy-bear-blue"})
-        assert await sync_to_async(form.is_valid)()
+        assert await form.ais_valid()
         obj = await form.asave()
         form = ProductForm({"slug": "teddy-bear-blue"})
-        await sync_to_async(form.full_clean)()
-        assert len(form.errors) == 1
-        assert form.errors["slug"] == ["Product with this Slug already exists."]
+        errors = await form.aerrors
+        assert len(errors) == 1
+        assert errors["slug"] == ["Product with this Slug already exists."]
         form = ProductForm({"slug": "teddy-bear-blue"}, instance=obj)
-        assert await sync_to_async(form.is_valid)()
+        assert await form.ais_valid()
 
     async def test_unique_together(self):
         """ModelForm test of unique_together constraint"""
         form = PriceForm({"price": "6.00", "quantity": "1"})
-        assert await sync_to_async(form.is_valid)()
+        assert await form.ais_valid()
         await form.asave()
         form = PriceForm({"price": "6.00", "quantity": "1"})
-        assert await sync_to_async(form.is_valid)() is False
-        await sync_to_async(form.full_clean)()
-        assert len(form.errors) == 1
-        assert form.errors["__all__"] == [
+        assert await form.ais_valid() is False
+        errors = await form.aerrors
+        assert len(errors) == 1
+        assert errors["__all__"] == [
             "Price with this Price and Quantity already exists."
         ]
 
@@ -1044,15 +1044,13 @@ class Meta:
     async def test_unique_null(self):
         title = "I May Be Wrong But I Doubt It"
         form = BookForm({"title": title, "author": self.writer.pk})
-        assert await sync_to_async(form.is_valid)()
+        assert await form.ais_valid()
         await form.asave()
         form = BookForm({"title": title, "author": self.writer.pk})
-        assert await sync_to_async(form.is_valid)() is False
-        await sync_to_async(form.full_clean)()
-        assert len(form.errors) == 1
-        assert form.errors["__all__"] == [
-            "Book with this Title and Author already exists."
-        ]
+        assert await form.ais_valid() is False
+        errors = await form.aerrors
+        assert len(errors) == 1
+        assert errors["__all__"] == ["Book with this Title and Author already exists."]
         form = BookForm({"title": title})
         assert form.is_valid()
         await form.asave()
@@ -1079,12 +1077,12 @@ def test_inherited_unique(self):
     async def test_inherited_unique_together(self):
         title = "Boss"
         form = BookForm({"title": title, "author": self.writer.pk})
-        assert await sync_to_async(form.is_valid)()
+        assert await form.ais_valid()
         await form.asave()
         form = DerivedBookForm(
             {"title": title, "author": self.writer.pk, "isbn": "12345"}
         )
-        assert await sync_to_async(form.is_valid)() is False
+        assert await form.ais_valid() is False
         assert len(form.errors) == 1
         assert form.errors["__all__"] == [
             "Book with this Title and Author already exists."
@@ -1134,10 +1132,10 @@ def test_explicitpk_unspecified(self):
     async def test_explicitpk_unique(self):
         """Ensure keys and blank character strings are tested for uniqueness."""
         form = ExplicitPKForm({"key": "key1", "desc": ""})
-        assert await sync_to_async(form.is_valid)()
+        assert await form.ais_valid()
         await form.asave()
         form = ExplicitPKForm({"key": "key1", "desc": ""})
-        assert await sync_to_async(form.is_valid)() is False
+        assert await form.ais_valid() is False
         if connection.features.interprets_empty_strings_as_nulls:
             assert len(form.errors) == 1
             assert form.errors["key"] == ["Explicit pk with this Key already exists."]
@@ -1397,7 +1395,7 @@ async def test_initial_values(self):
             },
         )
         assertHTMLEqual(
-            await sync_to_async(f.as_ul)(),
+            await f.aas_ul(),
             """
             <li>Headline:
             <input type="text" name="headline" value="Your headline here" maxlength="50"
@@ -1446,9 +1444,9 @@ async def test_initial_values(self):
         )
         art_id_1 = art.id
 
-        f = await sync_to_async(ArticleForm)(auto_id=False, instance=art)
+        f = await ArticleForm.from_async(auto_id=False, instance=art)
         assertHTMLEqual(
-            await sync_to_async(f.as_ul)(),
+            await f.aas_ul(),
             """
             <li>Headline:
             <input type="text" name="headline" value="Test article" maxlength="50"
@@ -1481,7 +1479,7 @@ async def test_initial_values(self):
             % (self.w_woodward.pk, self.w_royko.pk, self.c1.pk, self.c2.pk, self.c3.pk),
         )
 
-        f = await sync_to_async(ArticleForm)(
+        f = await ArticleForm.from_async(
             {
                 "headline": "Test headline",
                 "slug": "test-headline",
@@ -1491,8 +1489,7 @@ async def test_initial_values(self):
             },
             instance=art,
         )
-        await sync_to_async(f.full_clean)()
-        assert f.errors == {}
+        assert await f.aerrors == {}
         assert f.is_valid()
         test_art = await f.asave()
         assert test_art.id == art_id_1
@@ -1521,7 +1518,7 @@ def formfield_for_dbfield(db_field, **kwargs):
         )
         form = ModelForm()
         assertHTMLEqual(
-            await sync_to_async(form.as_ul)(),
+            await form.aas_ul(),
             """<li><label for="id_headline">Headline:</label>
 <input id="id_headline" type="text" name="headline" maxlength="50" required></li>
 <li><label for="id_categories">Categories:</label>
@@ -1640,9 +1637,9 @@ async def test_multi_fields(self):
         )
         await new_art.categories.aadd(await Category.objects.aget(name="Entertainment"))
         assert [art async for art in new_art.categories.all()] == [self.c1]
-        f = await sync_to_async(ArticleForm)(auto_id=False, instance=new_art)
+        f = await ArticleForm.from_async(auto_id=False, instance=new_art)
         assertHTMLEqual(
-            await sync_to_async(f.as_ul)(),
+            await f.aas_ul(),
             """
             <li>Headline:
             <input type="text" name="headline" value="New headline" maxlength="50"
@@ -1760,7 +1757,7 @@ async def test_m2m_editing(self):
         # Now, submit form data with no categories. This deletes the existing
         # categories.
         form_data["categories"] = []
-        f = await sync_to_async(ArticleForm)(form_data, instance=new_art)
+        f = await ArticleForm.from_async(form_data, instance=new_art)
         new_art = await f.asave()
         assert new_art.id == art_id_1
         new_art = await Article.objects.aget(id=art_id_1)
@@ -1826,7 +1823,7 @@ async def test_runtime_choicefield_populated(self):
         await self.create_basic_data()
         f = ArticleForm(auto_id=False)
         assertHTMLEqual(
-            await sync_to_async(f.as_ul)(),
+            await f.aas_ul(),
             '<li>Headline: <input type="text" name="headline" maxlength="50" required>'
             "</li>"
             '<li>Slug: <input type="text" name="slug" maxlength="50" required></li>'
@@ -1855,7 +1852,7 @@ async def test_runtime_choicefield_populated(self):
         c4 = await Category.objects.acreate(name="Fourth", url="4th")
         w_bernstein = await Writer.objects.acreate(name="Carl Bernstein")
         assertHTMLEqual(
-            await sync_to_async(f.as_ul)(),
+            await f.aas_ul(),
             '<li>Headline: <input type="text" name="headline" maxlength="50" required>'
             "</li>"
             '<li>Slug: <input type="text" name="slug" maxlength="50" required></li>'
@@ -1984,7 +1981,7 @@ def __init__(self, *args, **kwargs):
             "article": "lorem ipsum",
         }
         form = MyForm(data)
-        assert await sync_to_async(form.is_valid)()
+        assert await form.ais_valid()
         article = await form.asave()
         assert article.writer == w
 
@@ -2264,7 +2261,7 @@ class Meta:
 
         form = WriterProfileForm()
         assertHTMLEqual(
-            await sync_to_async(form.as_p)(),
+            await form.aas_p(),
             """
             <p><label for="id_writer">Writer:</label>
             <select name="writer" id="id_writer" required>
@@ -2291,7 +2288,7 @@ class Meta:
 
         form = WriterProfileForm(instance=instance)
         assertHTMLEqual(
-            await sync_to_async(form.as_p)(),
+            await form.aas_p(),
             """
             <p><label for="id_writer">Writer:</label>
             <select name="writer" id="id_writer" required>