feat: custom login form class (#1634)

Author: lukasvinclav

docs/configuration/settings.md

@@ -57,6 +57,8 @@ UNFOLD = {
     "LOGIN": {
         "image": lambda request: static("sample/login-bg.jpg"),
         "redirect_after": lambda request: reverse_lazy("admin:APP_MODEL_changelist"),
+        # Inherits from `unfold.forms.AuthenticationForm`
+        "form": "app.forms.CustomLoginForm",
     },
     "STYLES": [
         lambda request: static("css/style.css"),

src/unfold/settings.py

@@ -79,6 +79,7 @@
     "LOGIN": {
         "image": None,
         "redirect_after": None,
+        "form": None,
     },
     "EXTENSIONS": {"modeltranslation": {"flags": {}}},
 }

src/unfold/sites.py

@@ -47,7 +47,11 @@ def __init__(self, name: str = "admin") -> None:
 
         super().__init__(name)
 
-        if self.login_form is None:
+        custom_login_form = get_config(self.settings_name)["LOGIN"]["form"]
+
+        if custom_login_form is not None:
+            self.login_form = import_string(custom_login_form)
+        elif self.login_form is None:
             self.login_form = AuthenticationForm
 
     def get_urls(self) -> list[URLPattern]: