--- title: Expressions --- The property mapping should return a value that is expected by the Provider/Source. Supported types are documented in the individual Provider/Source. Returning `None` is always accepted and would simply skip the mapping for which `None` was returned. ## Available Functions import Functions from "../expressions/_functions.md"; <Functions /> ## Variables import Objects from "../expressions/_objects.md"; <Objects /> import User from "../expressions/_user.md"; <User /> - `request`: The current request. This may be `None` if there is no contextual request. See ([Django documentation](https://docs.djangoproject.com/en/3.0/ref/request-response/#httprequest-objects)) - Other arbitrary arguments given by the provider, this is documented on the Provider/Source.