Enhancement: use charfield for webhook url, custom validation (#9128)

---------

Co-authored-by: Trenton H <797416+stumpylog@users.noreply.github.com>

src/documents/validators.py

@@ -4,11 +4,18 @@ from django.core.exceptions import ValidationError
 from django.utils.translation import gettext_lazy as _
 
 
-def uri_validator(value) -> None:
+def uri_validator(value: str, allowed_schemes: set[str] | None = None) -> None:
     """
-    Raises a ValidationError if the given value does not parse as an
-    URI looking thing, which we're defining as a scheme and either network
-    location or path value
+    Validates that the given value parses as a URI with required components
+    and optionally restricts to specific schemes.
+
+    Args:
+        value: The URI string to validate
+        allowed_schemes: Optional set/list of allowed schemes (e.g. {'http', 'https'}).
+                        If None, all schemes are allowed.
+
+    Raises:
+        ValidationError: If the URI is invalid or uses a disallowed scheme
     """
     try:
         parts = urlparse(value)
@@ -22,8 +29,32 @@ def uri_validator(value) -> None:
                 _(f"Unable to parse URI {value}, missing net location or path"),
                 params={"value": value},
             )
+
+        if allowed_schemes and parts.scheme not in allowed_schemes:
+            raise ValidationError(
+                _(
+                    f"URI scheme '{parts.scheme}' is not allowed. Allowed schemes: {', '.join(allowed_schemes)}",
+                ),
+                params={"value": value, "scheme": parts.scheme},
+            )
+
+    except ValidationError:
+        raise
     except Exception as e:
         raise ValidationError(
             _(f"Unable to parse URI {value}"),
             params={"value": value},
         ) from e
+
+
+def url_validator(value) -> None:
+    """
+    Validates that the given value is a valid HTTP or HTTPS URL.
+
+    Args:
+        value: The URL string to validate
+
+    Raises:
+        ValidationError: If the URL is invalid or not using http/https scheme
+    """
+    uri_validator(value, allowed_schemes={"http", "https"})