ModelInfoChoicesBaseViewSet

Overview

Base of the two choice endpoints, which list the {label, value} options of one field or filter on a registered model.

The URL names the model by app_label and model (the lowercase model name that its content type stores) and the field or filter by field. A request passes three checks in order:

1. The model must be registered with register or register_serializer. Otherwise the endpoint answers 404 with Unable to find the content type "<app_label>.<model>". The model that a relation points at does not need to be registered.
2. resolve_choices finds the field or filter. A name that the model does not offer answers 404, and the message lists the valid names.
3. check_permissions checks read on the model, plus list on the related model when the options are another model's rows. A missing permission answers 403. The codenames go through PERMISSION_NAMES_MAPPING. The viewset sets no permission_classes, so these are the only permission checks.

Every value is a string, whatever the column type. Responses are paginated like other VUEDA lists. The search and ordering filter backends are removed, so the endpoints take no search or ordering parameter.

__init__

Constructor. Called in the URLconf; can contain helpful extra keyword arguments, and other things.

Signature

__init__(args, kwargs)

Parameters

Name	Type	Required	Default	Description
args		no
kwargs		no

Source

server/vueda/info/viewsets.py:132

canonical

Signature

canonical(unknown)

Parameters

Name	Type	Required	Default	Description
unknown		yes

check_permissions

For fields: If the choices are hard coded on a field, then we check 'read' on the current model. If the choices are a foreign key then we check 'read' on the current model and 'list' on the related model.

For filters: If the choices are hard coded on the filter, then we check 'read' on the current model, because you may not be able to 'list' it. If the choices are a foreign key on the filter, then we check 'read' on the current model and 'list' on the related model.

For serializer-only fields (neither a model field nor a model relation): We check 'read' on the current model, and for a related field also 'list' on the model of the field's queryset.

An unknown field name never reaches this check, because resolve_choices raises Http404 for it first.

Signature

check_permissions(self, request)

Parameters

Name	Type	Required	Default	Description
self		yes
request		yes

Source

server/vueda/info/viewsets.py:160

dispatch

Dispatch the incoming request to the appropriate handler method.

This method implements the core request/response lifecycle for Django REST Framework views:

1. Wraps the incoming Django HttpRequest in a REST framework Request.
2. Performs content negotiation, authentication, permission, and throttling checks.
3. Resolves and calls the appropriate HTTP method handler (e.g. get(), post(), put()).
4. Handles any exceptions raised during processing and converts them into appropriate Response objects.
5. Finalizes and returns the response with proper rendering and headers applied.

Signature

dispatch(self, request, app_label, model, field, args, kwargs)

Parameters

Name	Type	Required	Default	Description
self		yes
request		yes
app_label		yes
model		yes
field		yes
args		no
kwargs		no

Source

server/vueda/info/viewsets.py:191

get_content_type_instance

Signature

get_content_type_instance(self)

Parameters

Name	Type	Required	Default	Description
self		yes

Source

server/vueda/info/viewsets.py:216

get_formatted_name_lookup_expression

Signature

get_formatted_name_lookup_expression(self, queryset)

Parameters

Name	Type	Required	Default	Description
self		yes
queryset		yes

Source

server/vueda/info/viewsets.py:208

initial

Runs anything that needs to occur prior to calling the method handler.

Signature

initial(self, request, args, kwargs)

Parameters

Name	Type	Required	Default	Description
self		yes
request		yes
args		no
kwargs		no

Source

server/vueda/info/viewsets.py:198

resolve_choices

Resolve the addressed field, the permissions it requires, and the state that get_queryset needs to build the choices.

DRF calls check_permissions before it calls the handler, so resolution cannot wait for get_queryset. Subclasses store their resolved state on the instance, raise Http404 for a field the model does not offer, and tolerate repeat calls.

Signature

resolve_choices(self)

Parameters

Name	Type	Required	Default	Description
self		yes

Source

server/vueda/info/viewsets.py:149

choices_content_types

choices_resolved

filter_backends

object

permission_classes

queryset

serializer_class

Source

server/vueda/info/viewsets.py:104