Should I use useselector/useDispatch instead of mapStateToProps

Answer 1

The redux state returned from the useSelector hook can be passed around anywhere else just like its done for mapStateToProps. Example: It can be passed to another function too. Only constraint being that the hook rules has to be followed during its declaration:

1. It has to be declared only within a functional component.

2. During declaration, it can not be inside any conditional block . Sample code below

       function test(displayText) {
          return (
   {displayText}
   );
       }
   
       export function App(props) {
           const displayReady = useSelector(state => {
           return state.readyFlag;
           });
   
           const displayText = useSelector(state => {
           return state.displayText;
           });
   
           if(displayReady) {
               return 
               (
   
                   Outer
                   {test(displayText)}
   
               
   );
           }
           else {
           return null;
           }
       }
   

EDIT: Since OP has asked a specific question - which is about using it within a callback, I would like to add a specific code.In summary, I do not see anything that stops us from using useSelector hook output in a callback. Please see the sample code below, its a snippet from my own code that demonstrates this particular use case.

export default function CustomPaginationActionsTable(props) {
//Read state with useSelector.
const searchCriteria = useSelector(state => {
  return state && state.selectedFacets;
 });

//use the read state in a callback invoked from useEffect hook.
useEffect( ()=>{
  const postParams = constructParticipantListQueryParams(searchCriteria);
  const options = {
    headers: {
        'Content-Type': 'application/json'
    },
    validateStatus: () => true
  };
  var request = axios.post(PORTAL_SEARCH_LIST_ALL_PARTICIPANTS_URI, postParams, options)
      .then(function(response)
        { 
          if(response.status === HTTP_STATUS_CODE_SUCCESS) {
            console.log('Accessing useSelector hook output in axios callback. Printing it '+JSON.stringify(searchCriteria));
            
          }
                    
        })          
      .catch(function(error) {
      });
}, []);
}