How to fix the useEffect won't update unless refresh-CodePudding

//real time database listner :
const getJobStatusSnapshot = ()=> {

    const que = query(jobsCollectionRef, where("auth_ID", "==", user.uid))
    const unsubscribe = onSnapshot(que, (querySnapshot) => {
    const temp = [];
    querySnapshot.forEach((doc) => {
        // cities.push(doc.data());
        temp.push({...doc.data(), id:doc.id})
        // console.log({...doc.data(), id:doc.id})
        setJobDoc(temp)
    });
    
    

    })
    unsubscribe();

}

useEffect(()=>{
    getJobStatusSnapshot()
},[])

Sometime it doesn't retrieve the data. I tried to pass [jobDoc]. But it gives me the same results. And then suddenly returns bunch of errors. Also, I noticed that if I wanna retrieve the data first time, I have to comment out > unsubscribe()

CodePudding user response：

if you set your useEffect dependencies to [jobDoc] it will be trigger on mount and on jobDoc value update which happen inside setJobDoc(temp), so it will be infinite loop which give you a bunch of errors. So if you only provide that code, I think you should listen to [user] or [user.uid]. Everytime the user or user.uid change it will rerun the getJobStatusSnapshot.

useEffect(()=>{
    getJobStatusSnapshot()
},[user])

CodePudding user response：

You are setting [] as dependency in useEffect, that means it only will perform that action when loading the page.

https://reactjs.org/docs/hooks-effect.html