Event interceptors

[dmitry-korolev]

TBD

[berezinmv]

Problem

We need to modify event payload before it goes through reducers and epics.

Solution

Interceptor

Declare 'Interceptor' type. Interceptor is a function that accepts and returns event. Also, if interceptor returns null or undefined we assume that event have been canceled.

type Interceptor<T extends Event> = (event: T) => T?

Module

Extend 'Module' type with 'interceptors' property

type Module = {
  ...
  interceptors?: Interceptor[];
}

Helper

Create helper function to intercept only given type of events.

function createInterceptor(eventCreator, (event: Event) => Event?): Interceptor;

Usage

const unmaskValueInterceptor = createInterceptor(setValue, event => {
  event.payload = unmaskPayloadValues(event.payload)
  return event
})

const unmaskModule = {
  name: 'unmask',
  interceptors: [unmaskValueInterceptor]
};

[dmitry-korolev]

I think it can be done with plugins. Closing it temporary.