trigger a function on state change when condition is met-CodePudding

I have initial state null in redux store but i want to trigger a function when that state is populated with a promise response if it met a condition in state. this is my state in redux.

const Initial_state = { 
     orderStatus: null,
  }

when promise resolve state is updated like this

orderStatus={status:200,message:'order place"}

i want to run a function in my component whenever state is changed and only if status is 200. But if i use if statement it returns error as status does not exits in state initially

CodePudding user response：

if i well understand your question you should use the useEffect hook. Here is the documentation https://reactjs.org/docs/hooks-reference.html#useeffect.

So finally in your component you should have something like this :

useEffect(() => {
  if (orderStatus?.status === 200) {
    // Do something when status is 200
  }
}, [orderStatus]);

I also want to suggest to define an empty object rather than null for you default value on the redux store :

const Initial_state = { 
  orderStatus: {},
}

Hoping my answer can help you in your search.