createTransform

Creates a transformer, which can be applied to persist configurations.

Transformers are use to apply operations to your data during prior it being persisted or hydrated.

One use case for a transformer is to handle data that can't be parsed to a JSON string. For example a Map or Set. To handle these data types you could utilise a transformer that converts the Map/Set to/from an Array or Object.

This helper has been directly copied from redux-persist (opens new window), with the intention of maximising our compatibility with the redux-persist ecosystem.

redux-persist (opens new window) already has a robust set of transformer packages (opens new window) that have been built for it.

API

The function accepts the following arguments:

• inbound (data: any, key: string) => any; optional

  This function will be executed against data prior to it being persisted by the configured storage engine.

• outbound (data: any, key: string) => any; optional

  This function will be executed against data prior after it is extracted from the configured storage engine.

• configuration Object; optional

  Additional configuration for the transform. An object supporting the following properties.

  • whitelist Array<string>; optional

    The data keys that this transformer would apply to.

  • blacklist Array<string>; optional

    The data keys that this transformer would not apply to.