From 15f159ee08d43fecabc0659b83ff24d5b3f87819 Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 09:00:26 +0000
Subject: [PATCH 01/13] fix bug with optional fields in custom forms

---
 admin_ui/src/components/NewForm.vue | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/admin_ui/src/components/NewForm.vue b/admin_ui/src/components/NewForm.vue
index 110a67b4..de3daeac 100644
--- a/admin_ui/src/components/NewForm.vue
+++ b/admin_ui/src/components/NewForm.vue
@@ -14,7 +14,7 @@
                 v-bind:timeResolution="
                     schema?.extra?.time_resolution[columnName]
                 "
-                v-bind:format="property.format"
+                v-bind:format="getFormat(property)"
             />
         </div>
     </div>
@@ -23,7 +23,7 @@
 <script lang="ts">
 import { defineComponent, type PropType } from "vue"
 import InputField from "./InputField.vue"
-import { type Schema, getType } from "@/interfaces"
+import { type Schema, getType, getFormat } from "@/interfaces"
 
 export default defineComponent({
     props: {
@@ -37,6 +37,7 @@ export default defineComponent({
     },
     setup() {
         return {
+            getFormat,
             getType
         }
     }

From 91aa49b1afe92ab1c96884824bf9633658581ea0 Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 10:52:36 +0000
Subject: [PATCH 02/13] try older Ubuntu version for Playwright tests

https://github.com/microsoft/playwright/issues/30368
---
 .github/workflows/playwright.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/playwright.yaml b/.github/workflows/playwright.yaml
index 57fd8e3f..e6f17d85 100644
--- a/.github/workflows/playwright.yaml
+++ b/.github/workflows/playwright.yaml
@@ -9,7 +9,7 @@ on:
 jobs:
     playwright:
         name: "Playwright Tests"
-        runs-on: ubuntu-latest
+        runs-on: ubuntu-22.04
         steps:
             - name: "Checkout repository"
               uses: "actions/checkout@v4"

From a5500bff878451f6ef78e42731766ed9f7bd961b Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 11:01:45 +0000
Subject: [PATCH 03/13] fix linter errors

---
 piccolo_admin/endpoints.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/piccolo_admin/endpoints.py b/piccolo_admin/endpoints.py
index f1872385..253a2db6 100644
--- a/piccolo_admin/endpoints.py
+++ b/piccolo_admin/endpoints.py
@@ -100,13 +100,13 @@ class GroupItem(BaseModel):
 
 
 class GroupedTableNamesResponseModel(BaseModel):
-    grouped: t.Dict[str, t.List[str]] = Field(default_factory=list)
+    grouped: t.Dict[str, t.List[str]] = Field(default_factory=dict)
     ungrouped: t.List[str] = Field(default_factory=list)
 
 
 class GroupedFormsResponseModel(BaseModel):
     grouped: t.Dict[str, t.List[FormConfigResponseModel]] = Field(
-        default_factory=list
+        default_factory=dict
     )
     ungrouped: t.List[FormConfigResponseModel] = Field(default_factory=list)
 

From c016a4be03dc1f854cbf199a9fa5c327b3bd6264 Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 11:15:20 +0000
Subject: [PATCH 04/13] remove fastapi version pin

We need the latest version to get around a breaking change in Starlette's test client:

https://github.com/encode/starlette/discussions/2770
---
 requirements/test-requirements.txt | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/requirements/test-requirements.txt b/requirements/test-requirements.txt
index 3ce95ac8..d63cc378 100644
--- a/requirements/test-requirements.txt
+++ b/requirements/test-requirements.txt
@@ -4,9 +4,5 @@ flake8==7.0.0
 piccolo[postgres,sqlite]>=1.16.0
 playwright==1.41.2
 pytest-playwright==0.4.4
-httpx>=0.20.0
-# This is needed because newer versions of FastAPI use a Starlette version with
-# a `TestClient` which breaks rate limiting.
-# The changes to `TestClient` will likely be reverted in a future release, in
-# which case we can remove this version pin.
-fastapi==0.106.0
+httpx==0.28.1
+fastapi==0.115.6

From 4d8eef0e02401909d9327422e3fbff8806ec83fd Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 11:27:10 +0000
Subject: [PATCH 05/13] ignore linter errors

I'm pretty sure the type annotations on Starlette are wrong - passing a HTTPEndpoint in should be allowed.
---
 piccolo_admin/endpoints.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/piccolo_admin/endpoints.py b/piccolo_admin/endpoints.py
index 253a2db6..6405a070 100644
--- a/piccolo_admin/endpoints.py
+++ b/piccolo_admin/endpoints.py
@@ -680,7 +680,7 @@ def __init__(
 
         private_app.add_route(
             path="/change-password/",
-            route=change_password(
+            route=change_password(  # type: ignore
                 login_url="./../../public/login/",
                 session_table=session_table,
                 read_only=read_only,
@@ -786,7 +786,7 @@ def __init__(
 
         public_app.add_route(
             path="/logout/",
-            route=session_logout(session_table=session_table),
+            route=session_logout(session_table=session_table),  # type: ignore
             methods=["POST"],
         )
 

From 9d902736f396f8a964c6f7fef294a2ad00987b2f Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 12:07:34 +0000
Subject: [PATCH 06/13] add logic to work out if form fields are optional

---
 admin_ui/src/components/NewForm.vue |  6 ++++--
 admin_ui/src/interfaces.ts          |  4 ++++
 admin_ui/src/utils.ts               | 11 ++++++++++-
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/admin_ui/src/components/NewForm.vue b/admin_ui/src/components/NewForm.vue
index de3daeac..d31a7703 100644
--- a/admin_ui/src/components/NewForm.vue
+++ b/admin_ui/src/components/NewForm.vue
@@ -11,6 +11,7 @@
                 v-bind:columnName="String(columnName)"
                 v-bind:type="getType(property)"
                 v-bind:value="property.default"
+                v-bind:isNullable="isNullable(property)"
                 v-bind:timeResolution="
                     schema?.extra?.time_resolution[columnName]
                 "
@@ -23,7 +24,7 @@
 <script lang="ts">
 import { defineComponent, type PropType } from "vue"
 import InputField from "./InputField.vue"
-import { type Schema, getType, getFormat } from "@/interfaces"
+import { type Schema, getType, getFormat, isNullable } from "@/interfaces"
 
 export default defineComponent({
     props: {
@@ -38,7 +39,8 @@ export default defineComponent({
     setup() {
         return {
             getFormat,
-            getType
+            getType,
+            isNullable
         }
     }
 })
diff --git a/admin_ui/src/interfaces.ts b/admin_ui/src/interfaces.ts
index 0962eafa..2521ab7f 100644
--- a/admin_ui/src/interfaces.ts
+++ b/admin_ui/src/interfaces.ts
@@ -176,6 +176,10 @@ export const getType = (property: Property): string => {
     return (property.type || property.anyOf?.[0].type) as string
 }
 
+export const isNullable = (property: Property): boolean => {
+    return (property.anyOf ?? []).filter((i) => i.type == "null").length > 0
+}
+
 export const getFormat = (property: Property): string | undefined => {
     if (property.format) {
         return property.format
diff --git a/admin_ui/src/utils.ts b/admin_ui/src/utils.ts
index 16f93040..5b2e08c0 100644
--- a/admin_ui/src/utils.ts
+++ b/admin_ui/src/utils.ts
@@ -1,4 +1,9 @@
-import { type Schema, type OrderByConfig, getType } from "@/interfaces"
+import {
+    type Schema,
+    type OrderByConfig,
+    getType,
+    isNullable
+} from "@/interfaces"
 import router from "./router"
 import moment from "moment"
 
@@ -140,6 +145,10 @@ export function convertFormValue(params: {
     if (value == "null") {
         value = null
     } else if (property.extra?.nullable && value == "") {
+        // TODO We can potentially remove this in the future - isNullable does
+        // what we need.
+        value = null
+    } else if (isNullable(property) && value == "") {
         value = null
     } else if (getType(property) == "array") {
         value = JSON.parse(String(value))

From a3bc19f6f03058f1dca934950fbcc24e01eb9b0e Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 12:17:13 +0000
Subject: [PATCH 07/13] added a mega form for testing

---
 piccolo_admin/example/forms/__init__.py  |  2 +
 piccolo_admin/example/forms/mega_form.py | 55 ++++++++++++++++++++++++
 2 files changed, 57 insertions(+)
 create mode 100644 piccolo_admin/example/forms/mega_form.py

diff --git a/piccolo_admin/example/forms/__init__.py b/piccolo_admin/example/forms/__init__.py
index e5be730c..9353c511 100644
--- a/piccolo_admin/example/forms/__init__.py
+++ b/piccolo_admin/example/forms/__init__.py
@@ -2,10 +2,12 @@
 from .csv import FORM as CSV_FORM
 from .email import FORM as EMAIL_FORM
 from .image import FORM as IMAGE_FORM
+from .mega_form import FORM as MEGA_FORM
 
 FORMS = [
     CALCULATOR_FORM,
     CSV_FORM,
     EMAIL_FORM,
     IMAGE_FORM,
+    MEGA_FORM,
 ]
diff --git a/piccolo_admin/example/forms/mega_form.py b/piccolo_admin/example/forms/mega_form.py
new file mode 100644
index 00000000..cb79f338
--- /dev/null
+++ b/piccolo_admin/example/forms/mega_form.py
@@ -0,0 +1,55 @@
+import datetime
+import typing as t
+
+from pydantic import BaseModel
+from starlette.requests import Request
+
+from piccolo_admin.endpoints import FormConfig
+
+
+class MegaFormModel(BaseModel):
+    """
+    Used for testing a wide variety of field types.
+    """
+
+    boolean_field: bool = True
+    boolean_field_optional: t.Optional[bool] = None
+
+    float_field: float = 1.0
+    float_field_optional: t.Optional[float] = None
+
+    integer_field: int = 1
+    integer_field_optional: t.Optional[int] = None
+
+    string_field: str = "Hello world"
+    string_optional: t.Optional[str] = None
+
+    list_field: t.List[str] = ["a", "b", "c"]
+    list_field_optional: t.Optional[t.List[str]] = None
+
+    time_field: datetime.time = datetime.time(hour=12, minute=30)
+    time_field_optional: t.Optional[datetime.time] = None
+
+    date_field: datetime.date = datetime.date(year=1999, month=12, day=31)
+    date_field_optional: t.Optional[datetime.date] = None
+
+    datetime_field: datetime.datetime = datetime.datetime(
+        year=1999, month=12, day=31, hour=12, minute=30
+    )
+    datetime_field_optional: t.Optional[datetime.datetime] = None
+
+    timedelta_field: datetime.timedelta = datetime.timedelta(hours=1)
+    timedelta_field_optional: t.Optional[datetime.timedelta] = None
+
+
+async def handle_form(request: Request, data: MegaFormModel) -> str:
+    return data.model_dump_json(indent=4)
+
+
+FORM = FormConfig(
+    name="Mega Form",
+    pydantic_model=MegaFormModel,
+    endpoint=handle_form,
+    description="Used for testing all possible field types.",
+    form_group="Testing",
+)

From 619f4fcd0324ee3ba7077305d826549a1cd6fe8f Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 12:24:39 +0000
Subject: [PATCH 08/13] fix a small bug with resetting the form

It would remove all of the defaults - we're better just letting Vue recreate the form.
---
 admin_ui/src/components/FormAdd.vue | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/admin_ui/src/components/FormAdd.vue b/admin_ui/src/components/FormAdd.vue
index 08f2266b..994d7aa6 100644
--- a/admin_ui/src/components/FormAdd.vue
+++ b/admin_ui/src/components/FormAdd.vue
@@ -25,7 +25,7 @@
             </ul>
         </div>
 
-        <div v-show="!successMessage">
+        <div v-if="!successMessage">
             <FormErrors :errors="errors" v-if="errors.length > 0" />
 
             <form
@@ -93,8 +93,6 @@ export default defineComponent({
     },
     methods: {
         resetForm() {
-            const form = this.$refs.form as HTMLFormElement
-            form.reset()
             this.successMessage = null
             this.errors = []
         },

From 799f9b7bafa172f35cd5261e1bf2436e78bf60c5 Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 12:37:00 +0000
Subject: [PATCH 09/13] allow new line characters in form response

---
 admin_ui/src/components/FormAdd.vue | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/admin_ui/src/components/FormAdd.vue b/admin_ui/src/components/FormAdd.vue
index 994d7aa6..f024a1ff 100644
--- a/admin_ui/src/components/FormAdd.vue
+++ b/admin_ui/src/components/FormAdd.vue
@@ -10,7 +10,7 @@
 
         <div v-show="successMessage">
             <h1>{{ $t("Form submitted") }}</h1>
-            <p>{{ successMessage }}</p>
+            <p id="success_message">{{ successMessage }}</p>
             <ul>
                 <li>
                     <a href="#" @click.prevent="resetForm">{{
@@ -183,4 +183,8 @@ export default defineComponent({
 h1 {
     text-transform: capitalize;
 }
+
+p#success_message {
+    white-space: pre-wrap;
+}
 </style>

From 8b112d1c9a956d346b438862ef81944ce8918918 Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 12:42:37 +0000
Subject: [PATCH 10/13] update unit tests with new form

---
 piccolo_admin/example/forms/mega_form.py |  2 +-
 tests/test_endpoints.py                  | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/piccolo_admin/example/forms/mega_form.py b/piccolo_admin/example/forms/mega_form.py
index cb79f338..ff149a2b 100644
--- a/piccolo_admin/example/forms/mega_form.py
+++ b/piccolo_admin/example/forms/mega_form.py
@@ -51,5 +51,5 @@ async def handle_form(request: Request, data: MegaFormModel) -> str:
     pydantic_model=MegaFormModel,
     endpoint=handle_form,
     description="Used for testing all possible field types.",
-    form_group="Testing",
+    form_group="Test forms",
 )
diff --git a/tests/test_endpoints.py b/tests/test_endpoints.py
index 688aec57..ec5876c2 100644
--- a/tests/test_endpoints.py
+++ b/tests/test_endpoints.py
@@ -279,6 +279,7 @@ def test_forms(self):
 
         response = client.get("/api/forms/")
         self.assertEqual(response.status_code, 200)
+
         self.assertEqual(
             response.json(),
             [
@@ -305,6 +306,13 @@ def test_forms(self):
                     "slug": "download-schedule",
                     "description": "Download the schedule for the day.",
                 },
+                {
+                    "description": (
+                        "Used for testing all possible field types."
+                    ),
+                    "name": "Mega Form",
+                    "slug": "mega-form",
+                },
             ],
         )
 
@@ -522,6 +530,15 @@ def test_forms_grouped(self):
                             "slug": "booking-form",
                         }
                     ],
+                    "Test forms": [
+                        {
+                            "description": (
+                                "Used for testing all possible field types."
+                            ),
+                            "name": "Mega Form",
+                            "slug": "mega-form",
+                        }
+                    ],
                 },
                 "ungrouped": [
                     {

From e3bfdeea176d9b35b1619748e27d5e4ae6ae0814 Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 12:53:59 +0000
Subject: [PATCH 11/13] rename form

---
 piccolo_admin/example/forms/__init__.py       |  2 +-
 .../forms/{mega_form.py => nullable.py}       | 28 +++++++++----------
 tests/test_endpoints.py                       | 14 ++++------
 3 files changed, 21 insertions(+), 23 deletions(-)
 rename piccolo_admin/example/forms/{mega_form.py => nullable.py} (54%)

diff --git a/piccolo_admin/example/forms/__init__.py b/piccolo_admin/example/forms/__init__.py
index 9353c511..6cf310ae 100644
--- a/piccolo_admin/example/forms/__init__.py
+++ b/piccolo_admin/example/forms/__init__.py
@@ -2,7 +2,7 @@
 from .csv import FORM as CSV_FORM
 from .email import FORM as EMAIL_FORM
 from .image import FORM as IMAGE_FORM
-from .mega_form import FORM as MEGA_FORM
+from .nullable import FORM as MEGA_FORM
 
 FORMS = [
     CALCULATOR_FORM,
diff --git a/piccolo_admin/example/forms/mega_form.py b/piccolo_admin/example/forms/nullable.py
similarity index 54%
rename from piccolo_admin/example/forms/mega_form.py
rename to piccolo_admin/example/forms/nullable.py
index ff149a2b..471241d6 100644
--- a/piccolo_admin/example/forms/mega_form.py
+++ b/piccolo_admin/example/forms/nullable.py
@@ -7,49 +7,49 @@
 from piccolo_admin.endpoints import FormConfig
 
 
-class MegaFormModel(BaseModel):
+class NullableFieldsModel(BaseModel):
     """
     Used for testing a wide variety of field types.
     """
 
     boolean_field: bool = True
-    boolean_field_optional: t.Optional[bool] = None
+    boolean_field_nullable: t.Optional[bool] = None
 
     float_field: float = 1.0
-    float_field_optional: t.Optional[float] = None
+    float_field_nullable: t.Optional[float] = None
 
     integer_field: int = 1
-    integer_field_optional: t.Optional[int] = None
+    integer_field_nullable: t.Optional[int] = None
 
     string_field: str = "Hello world"
-    string_optional: t.Optional[str] = None
+    string_nullable: t.Optional[str] = None
 
     list_field: t.List[str] = ["a", "b", "c"]
-    list_field_optional: t.Optional[t.List[str]] = None
+    list_field_nullable: t.Optional[t.List[str]] = None
 
     time_field: datetime.time = datetime.time(hour=12, minute=30)
-    time_field_optional: t.Optional[datetime.time] = None
+    time_field_nullable: t.Optional[datetime.time] = None
 
     date_field: datetime.date = datetime.date(year=1999, month=12, day=31)
-    date_field_optional: t.Optional[datetime.date] = None
+    date_field_nullable: t.Optional[datetime.date] = None
 
     datetime_field: datetime.datetime = datetime.datetime(
         year=1999, month=12, day=31, hour=12, minute=30
     )
-    datetime_field_optional: t.Optional[datetime.datetime] = None
+    datetime_field_nullable: t.Optional[datetime.datetime] = None
 
     timedelta_field: datetime.timedelta = datetime.timedelta(hours=1)
-    timedelta_field_optional: t.Optional[datetime.timedelta] = None
+    timedelta_field_nullable: t.Optional[datetime.timedelta] = None
 
 
-async def handle_form(request: Request, data: MegaFormModel) -> str:
+async def handle_form(request: Request, data: NullableFieldsModel) -> str:
     return data.model_dump_json(indent=4)
 
 
 FORM = FormConfig(
-    name="Mega Form",
-    pydantic_model=MegaFormModel,
+    name="Nullable fields",
+    pydantic_model=NullableFieldsModel,
     endpoint=handle_form,
-    description="Used for testing all possible field types.",
+    description="Used for testing nullable fields.",
     form_group="Test forms",
 )
diff --git a/tests/test_endpoints.py b/tests/test_endpoints.py
index ec5876c2..6eadb312 100644
--- a/tests/test_endpoints.py
+++ b/tests/test_endpoints.py
@@ -307,11 +307,9 @@ def test_forms(self):
                     "description": "Download the schedule for the day.",
                 },
                 {
-                    "description": (
-                        "Used for testing all possible field types."
-                    ),
-                    "name": "Mega Form",
-                    "slug": "mega-form",
+                    "description": "Used for testing nullable fields.",
+                    "name": "Nullable fields",
+                    "slug": "nullable-fields",
                 },
             ],
         )
@@ -533,10 +531,10 @@ def test_forms_grouped(self):
                     "Test forms": [
                         {
                             "description": (
-                                "Used for testing all possible field types."
+                                "Used for testing nullable fields."
                             ),
-                            "name": "Mega Form",
-                            "slug": "mega-form",
+                            "name": "Nullable fields",
+                            "slug": "nullable-fields",
                         }
                     ],
                 },

From 05b5cf032c77970f7e2eeb7afd61e9d94559a941 Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Tue, 14 Jan 2025 13:08:15 +0000
Subject: [PATCH 12/13] add a playwright test

---
 e2e/test_forms.py | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/e2e/test_forms.py b/e2e/test_forms.py
index 933a5278..9af3cd92 100644
--- a/e2e/test_forms.py
+++ b/e2e/test_forms.py
@@ -2,7 +2,9 @@
 
 from piccolo_admin.example.forms.csv import FORM as CSV_FORM
 from piccolo_admin.example.forms.image import FORM as IMAGE_FORM
+from piccolo_admin.example.forms.nullable import FORM as NULLABLE_FORM
 
+from .conftest import BASE_URL
 from .pages import FormPage, LoginPage
 
 
@@ -54,3 +56,26 @@ def test_image_form(page: Page, dev_server):
 
     download = download_info.value
     assert download.suggested_filename == "movie_listings.jpg"
+
+
+def test_nullable_form(page: Page, dev_server):
+    """
+    Make sure a form with nullable fields can be submitted successfully.
+    """
+    login_page = LoginPage(page=page)
+    login_page.reset()
+    login_page.login()
+
+    form_page = FormPage(
+        page=page,
+        form_slug=NULLABLE_FORM.slug,
+    )
+    form_page.reset()
+
+    with page.expect_response(
+        lambda response: response.url
+        == f"{BASE_URL}/api/forms/nullable-fields/"
+        and response.request.method == "POST"
+        and response.status == 200
+    ):
+        form_page.submit_form()

From bc94e1bc0e62ed435344e4761e3a5f0b517b42ac Mon Sep 17 00:00:00 2001
From: Daniel Townsend <dan@dantownsend.co.uk>
Date: Thu, 16 Jan 2025 23:07:49 +0000
Subject: [PATCH 13/13] refactor so It's backwards compatible

---
 admin_ui/src/interfaces.ts |  1 +
 admin_ui/src/utils.ts      | 26 +++++++++++++++++---------
 2 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/admin_ui/src/interfaces.ts b/admin_ui/src/interfaces.ts
index 2521ab7f..d3bf2c84 100644
--- a/admin_ui/src/interfaces.ts
+++ b/admin_ui/src/interfaces.ts
@@ -176,6 +176,7 @@ export const getType = (property: Property): string => {
     return (property.type || property.anyOf?.[0].type) as string
 }
 
+// Determines if the property is nullable based off the OpenAPI type.
 export const isNullable = (property: Property): boolean => {
     return (property.anyOf ?? []).filter((i) => i.type == "null").length > 0
 }
diff --git a/admin_ui/src/utils.ts b/admin_ui/src/utils.ts
index 5b2e08c0..9725d593 100644
--- a/admin_ui/src/utils.ts
+++ b/admin_ui/src/utils.ts
@@ -140,17 +140,25 @@ export function convertFormValue(params: {
 }): any {
     let { key, value, schema } = params
 
+    if (value == "null") {
+        return null
+    }
+
     const property = schema.properties[key]
 
-    if (value == "null") {
-        value = null
-    } else if (property.extra?.nullable && value == "") {
-        // TODO We can potentially remove this in the future - isNullable does
-        // what we need.
-        value = null
-    } else if (isNullable(property) && value == "") {
-        value = null
-    } else if (getType(property) == "array") {
+    const nullable = property.extra?.nullable
+
+    if (nullable == true && value == "") {
+        return null
+    }
+
+    // For Piccolo custom forms, there is no `extra` attribute, instead we
+    // have to look at the OpenAPI schema:
+    if (nullable == undefined && isNullable(property) && value == "") {
+        return null
+    }
+
+    if (getType(property) == "array") {
         value = JSON.parse(String(value))
     }