Custom Vars

As mentioned in the vars page, Reflex vars must be JSON serializable.

This means we can support any Python primitive types, as well as lists, dicts, and tuples. However, you can also create more complex var types using dataclasses (recommended), TypedDict, or Pydantic models.

Defining a Type

In this example, we will create a custom var type for storing translations using a dataclass.

Once defined, we can use it as a state var, and reference it from within a component.

Alternative Approaches

Using TypedDict

You can also use TypedDict for defining custom var types:

Using Pydantic Models

Pydantic models are another option for complex data structures:

For complex data structures, dataclasses are recommended as they provide a clean, type-safe way to define custom var types with good IDE support.