addObserver Pipemethod

Description

State Change Post Notification middleware： addObserver is the post-notification middleware for all state change executions under current pipe, adding the middleware in the form of a callback function.

Usage

addObserver(
  (rootStore, [...path], stateKey, value, {mode}) => {}
)

Arguments

rootStore (Object/Array): root store paths (Array = []): action path stateKey (String): state key value (*): The state has changed value, as mode is {mode: ' delete '} then this parameter does not exist. mode(Object = { mode:(String) }): state action type (delete/set/batch)

Returned value

(*): none

Examples

pipe.addObserver(
  (root, ...args)=>{
    const {mode} = args.pop()
    const value = args.pop()
    const stateKey = args.pop()
    const path = args
    //do something
  }
)