I have noticed that hooks set functions are asynchonous but I need to call a function once my new value has been set.
This is how my state looks:
const[agenda, setAgenda] = useState([{ id: "0", date:new Date(2022,0,21,13,25,0), titulo: "Test 1", obs:'Lorem ipsum dolor sit amet', prioridade:1,local:'-',lugar:'', diatodo:false },
{ id: "1", date:new Date(2022,0,21,13,25,0), titulo: "Test 2", obs:'Lorem ipsum dolor sit amet', prioridade:1,local:'-',lugar:'', diatodo:false }])
It's an array so I don't know how to do it, I have tried doing this:
setAgenda({[...agenda,obj]},testFunction);
Visual Studio Code gives me the following error though: Error
How should I do it? Thanks in advance
CodePudding user response：
This is an invalid way of setting the state.
The function for setting the state only take one argument.
If you want a function to run when the state changes you will have to use the useEffect hook. This useEffect hook will have the state as a dependency.
useEffect(() => {
//do stuff
}, [agenda]);
Also, if you defined your function the same component, you will have to do one of those 3 things (your choice):
- Write the function directly inside the useEffect.
- Add the function as a dependency of useEffect.
- Wrap the function with a useCallback.
https://reactjs.org/docs/hooks-effect.html