Enable ImageField forms rendering

Author: insspb

flask_mongoengine/db_fields.py

@@ -725,18 +725,15 @@ class ImageField(WtfFieldMixin, fields.ImageField):
     All arguments should be passed as keyword arguments, to exclude unexpected behaviour.
     """
 
-    def to_wtf_field(
-        self,
-        *,
-        model: Optional[Type] = None,
-        field_kwargs: Optional[dict] = None,
-    ):
-        """
-        Protection from execution of :func:`to_wtf_field` in form generation.
+    DEFAULT_WTF_FIELD = custom_fields.MongoImageField if custom_fields else None
 
-        :raises NotImplementedError: Field converter to WTForm Field not implemented.
-        """
-        raise NotImplementedError("Field converter to WTForm Field not implemented.")
+    @property
+    @wtf_required
+    def wtf_generated_options(self) -> dict:
+        """Inserts accepted type in widget rendering (does not do validation)."""
+        options = super().wtf_generated_options
+        options["render_kw"] = {"accept": "image/*"}
+        return options
 
 
 class IntField(WtfFieldMixin, fields.IntField):

flask_mongoengine/wtf/fields.py

@@ -436,6 +436,12 @@ class MongoHiddenField(EmptyStringIsNoneMixin, wtf_fields.HiddenField):
     pass
 
 
+class MongoImageField(MongoFileField):
+    """GridFS image field."""
+
+    widget = mongo_widgets.MongoImageInput()
+
+
 class MongoPasswordField(EmptyStringIsNoneMixin, wtf_fields.PasswordField):
     """
     Regular :class:`wtforms.fields.PasswordField`, that transform empty string to `None`.

tests/test_db_fields.py

@@ -158,7 +158,6 @@ def test__ensure_callable_or_list__raise_error_if_argument_not_callable_and_not_
             db_fields.GenericReferenceField,
             db_fields.GeoJsonBaseField,
             db_fields.GeoPointField,
-            db_fields.ImageField,
             db_fields.LazyReferenceField,
             db_fields.LineStringField,
             db_fields.ListField,