react_to_events.md

React to Actions

The main purpose of redux-ruleset is to react to dispatched actions. You can define the action type(s) a rule should react to with the target key. The rule will react to every action-type you define here. If you set the target to '*' the rule will react to ANY action.

import {addRule} from 'redux-ruleset'

addRule({
  id: 'PING_PONG',
  target: 'PING', // rule will be executed for every action with type PING
  consequence: () => ({type: 'PONG'})
})

addRule({
  id: 'TRIGGER_PRODUCT_SEARCH',
  target: ['SET_COLOR_FILTER', 'SET_QUERY'], // rule will be executed for both actions
  consequence: () => ({type: 'FETCH_PRODUCTS'})
})

addRule({
  id: 'LOGGER',
  target: '*', // rule will be executed for every action
  consequence: action => console.log(action)
})

A rule will only be touched when the target matches. This is because rules are stored in a map, where the key is it's target. This gives redux-ruleset a huge performance boost. Even if you add dozens of rules you won't come into performance problems, because only a few rules will get touched per action.

In addition, it's possible to add conditions, when a rule should be executed. When the target matches we can control with the condition key, whether the consequence should be applied or not.

import {addRule} from 'redux-ruleset'

addRule({
  id: 'LOG_COLOR',
  target: 'SET_FILTER',
  condition: action => action.meta.filterKey === 'COLOR',
  consequence: action => console.log('you set color to' + action.payload)
})

dispatch({ type: 'SET_FILTER', meta: {filterKey: 'COLOR'}, payload: 'silver' })
// => you set color to silver

dispatch({ type: 'SET_FILTER', meta: {filterKey: 'SIZE'}, payload: 'big' })
// => nothing happens

As long as the condition does not match, the consequence won't be executed.