Consequence

The consequence is the heart of each rule. Here is the only place you can perform side-effects. It is a required key

type Consequence = (
  Action,
  {
    dispatch:Dispatch,
    getState:GetState,
    addRule: (ruleId:string, context:Object) => void,
    removeRule: (ruleId:string) => void,
    effect: (()=>mixed) => void
    context: {
      get: (key:string) => mixed
    }
  }
) => Action | Promise<Action> | Promise<void> | void | () => void

To perform side-effects you should only use methods provided in the arguments. These methods (like dispatch, addRule) are overloaded versions that are able to be canceled. If you use e.g the global addRule function it can lead to unwanted behaviour. Read more about how to perform side-effects in the dispatching actions section.

A consequence can return different types. Based on this return type different things will happen:

• return an action
• return an promise-wrapped action
• return a callback