I am trying to set the state of a variable "workspace", but when I console log the data I get an infinite loop. I am calling the axios "get" function inside of useEffect(), and console logging outside of this loop, so I don't know what is triggering all the re-renders. I have not found an answer to my specific problem in this question . Here's my code:
function WorkspaceDynamic({ match }) {
const [proposals, setProposals] = useState([{}]);
useEffect(() => {
getItems();
});
const getItems = async () => {
const proposalsList = await axios.get(
"http://localhost:5000/api/proposals"
);
setProposals(proposalsList.data);
};
const [workspace, setWorkspace] = useState({});
function findWorkspace() {
proposals.map((workspace) => {
if (workspace._id === match.params.id) {
setWorkspace(workspace);
}
});
}
Does anyone see what might be causing the re-render? Thanks!
The effect hook runs every render cycle, and one without a dependency array will execute its callback every render cycle. If the effect callback updates state, ie proposals
, then another render cycle is enqueued, thus creating render looping.
If you want to only run effect once when the component mounts then use an empty dependency array.
useEffect(() => {
getItems();
}, []);
If you want it to only run at certain time, like if the match param updates, then include a dependency in the array.
useEffect(() => {
getItems();
}, [match]);
your use of useEffect is not correct. if your dependency array is empty it gets called every time any state data changes.as a result your useEffect
is called which causes setProposals
then it again causes useEffect
to run and so on
try this
useEffect(() => {
getItems();
} , []); // an empty array means it will be called once only
I think it's the following: useEffect
should have a second param []
to make sure it's executed only once. that is:
useEffect(() => {
getItems();
}, []);
otherwise setProposal
will modify the state which will trigger a re-render, which will call useEffect
, which will make the async call, which will setProposal
, ...
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