Using an object with empty Properties, having all properties inside AdditionalProperties

[ErikKoinberg]

I have a usage case in which I need the user to define a set of custom properties. I do not want nor need any normal properties. Adding any would just be unnecessary and obtrusive. Is it possible to make an object with empty "properties" or at least hide a fields inside of that for the end user, as a possible fix?

[ErikKoinberg]

I solved this using widget: hidden

[pirate]

I think this should be re-opened as the original use-case should still be supported by the library without a workaround.

In my case I'm using django-pydantic-field and I have a field like this: my_mapping: Dict[str, str] = Field(default={}) that has no properties/keys pre-defined.

I need the widget working and visible to allow users to edit this value and add str: str mapping entries.

I think django-jsonform should support objects with no properties or keys defined as long as they have additionalProperties set.

I've also noticed that if the object is already populated with some user-provided additional parameters that aren't defined in properties/keys, they don't show up in the UI at all. This makes it hard to implement these forms to edit Dict[str, str] because entries "disappear" after the user hits save and refreshes.

Related issue: https://github.com/surenkov/django-pydantic-field/issues/64

[pirate]

As a workaround I've monkey-patched JSONFormWidget to achieve the desired behavior:

from django.contrib import admin

from django_jsonform.widgets import JSONFormWidget
from django_pydantic_field.v2.fields import PydanticSchemaField

from project.models import Dependency

def patch_schema_for_jsonform(schema):
    """recursively patch a schema dictionary in-place to fix any missing properties/keys on objects"""

    # base case: schema is type: "object" with no properties/keys
    if schema.get('type') == 'object' and not ('properties' in schema or 'keys' in schema):
        if 'default' in schema and isinstance(schema['default'], dict):
            schema['properties'] = {
                key: {"type": "string", "default": value}
                for key, value in schema['default'].items()
            }
            # setting the actual value as a default on a hardcoded property is still not ideal as it doesn't allow the user to remove this entry from the UI, but at least it shows up
        else:
            schema['properties'] = {}

    # recursive case: iterate through all values and process any sub-objects
    for key, value in schema.items():
        if isinstance(value, dict):
            patch_schema_for_jsonform(value)

class PatchedJSONFormWidget(JSONFormWidget):
    def get_schema(self):
        self.schema = super().get_schema()
        patch_schema_for_jsonform(self.schema)
        return self.schema

class DependencyAdmin(admin.ModelAdmin):
    formfield_overrides = {PydanticSchemaField: {"widget": PatchedJSONFormWidget}}

admin.site.register(Dependency, DependencyAdmin)