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Updating a state variable with a new reference doesn't trigger re-rendering in React

I'm writing a table component for my page in React.
I have a function loadData() that makes a request to an api. Using the api result to update the data state variable, using a new reference.
The problem here is that React doesn't trigger any re-render for the data variable.
const [data, setData] = useState([]);
const loadData = async () => {
try {
...
let response_json = await response.json();
setData(transformData(response_json.items));
...
}
const transformData = (data) => {
if (data === undefined || data === null) {
return [];
}
let new_data = [];
data.forEach((entry,index) => {
new_data.push(cloneElement(props.config.table_entry,{data:entry, key:index}, null));
});
return new_data;
}
I am using this code to change the table's page, making a request with parameters like pageNumber, pageSize, filters. So even with different data and different reference, still it doesn't trigger re-rendering.

This problem has challenged me for like one whole morning was that the data variable continued to updated on every request made but the webpage never re-rendered.
The answer lies here
data.forEach((entry,index) => {
new_data.push(cloneElement(props.config.table_entry,{data:entry, key:index}, null));
});
in the transformData function where it creates a new array of new data, BUT the key property of the component never changed because it was the index of its position in the array returned from the server.
Assigning the key to a unique id solved the problem.

how to detect if user is typing in react native?

I have an application in react native where i'm developing a search feature like Instagram.
It is like if user stop typing show him his query result.
my current approach is messing up redux. And sometimes it returns same element multiple times or sometime random elements which are irrelevant of that query.
right now. I'm calling search api immediately as use start typing in searchbar.
here is code below of my component.
import { getSearchDataApi } from "../../api/search/search";
import { clearSearchData, setSearchData } from "../../redux/action/search";
const SearchScreen =(props)=>{
const [autoFocus,setAutoFocus] = useState(true)
const [keyWord,setKeyWord] = useState(null)
const [isLoading,setIsLoading] = useState(false)
const [isError,setIsError] = useState(false)
const [pageNumber,setPageNumber] = useState(1)
const [loadMore,setLoadMore] = useState(true)
const loadMoreDataFunc =()=>{
if (pageNumber <= props.totalSearchPage) {
setPageNumber(pageNumber+1)
}
else {
setLoadMore(false)
}
}
const searchData = async(keyWord)=>{
console.log(keyWord,pageNumber)
try {
setIsLoading(true)
var searchResponse = await getSearchDataApi(keyWord,pageNumber)
props.setSearchData(searchResponse.data)
setIsLoading(false)
}
catch (e) {
setIsError(true)
console.log("Error --- ", e.response.data.message)
showMessage({
message: e.response.data.message,
type: "danger",
});
}
}
return (
<View>
....
</View>
)
}
const mapStateToProps = (state)=>({
searchData: state.searchReducer.searchData,
totalSearchPage: state.searchReducer.totalSearchPage,
})
export default connect(mapStateToProps,{setSearchData,clearSearchData})(SearchScreen);
I will really every thankful to someone how can help me in fixing. Appreciation in advance!
GOAL :
The goal that i want to achieve is when user stop typing then i call searchAPI with the keyword he/she entered in searchBar that's all.
I have also tried setTimeOut but that made things more worse.

The best solution to your problem is to debounce the state variable that is responsible for the user input. This way, you can use the effect hook to watch for changes on the debounced variable, and call the search API if/when conditions for the search API variables are met.

Well, I have put some effort to solve it with setTimeout once again and i have done it by following code of snippet.
useEffect(()=>{
setPageNumber(1)
props.clearSearchData()
const delayDebounceFn = setTimeout(() => {
console.log(keyWord)
if (keyWord) {
searchData(keyWord)
}
}, 500)
return () => clearTimeout(delayDebounceFn)
},[keyWord])

You can use a setInterval to create a countDown starting from 2 to 0, or 3 to 0, put it a state.
whenever user types, onChange is called, the from the callback you reset the countDown.
using useEffect with the countDown as dependency, you can open the search result whenever the countdown reaches 0. (which means the user hasn't typed anything since 2s ago)
this might help for creating the countdown https://blog.greenroots.info/how-to-create-a-countdown-timer-using-react-hooks

react js How to keep the initial data saved after applying the fitler on array

I am working on a React JS based UI and facing an issue wiht data .
I fetch data from an API and store it in an initial value by using useState hook.
Then I use useEffect to store it in 'lists' via setLists()
const [lists, setLists] = useState([]);
useEffect(()=>{
const url = "https://domain/api/all";
fetch(url).then(response => response.json()).then(response=> {
setLists(response.json.list);
});
Now I am able to use map to enter data in a table
Lists is an array object that has multiple values in it and I want t filter the table based on age and country
let [ageList, setAgeList] = useState([]);
let [countryList, setcoutryList] = useState([]);
useEffect(()=>{
var newList = lists.filter(e=> e.age === age);
setList(newList)
},[age])
useEffect(()=>{
setlist(lists.filter(e=> e.country === country))
},[country])
With this method first attempt of filter works fine by both Age and Country but when I change the value of the filter for age or country then I get empty array which is expected as the new lists variable has entered with last filtered country/age
How can I get over this?

As you noticed, when you overwrite your previous state with the filtered state, you lose the previous state forever. The solution here is to keep the initial value of lists and create a new variable for your filtered lists. Something like this:
const [lists, setLists] = useState([]);
const [ageFilter, setAgeFilter] = useState("");
const [countryFilter, setcountryFilter] = useState("");
const url = "https://domain/api/all";
fetch(url)
.then(response => response.json())
.then(response=> {
setLists(response.json.list);
});
let filteredByCountryAndAge = listfilter((listItem) => {
return (listItem.country === countryFilter && listItem.age === ageFilter);
});
(or however else you are filtering it).
The point being, do not change the value of lists after it is set with the entire list. When filtering, assign the criteria by which you are filtering to state variables, but assign the filtered data to a variable—NOT a state variable.

Do you have control over the fetched data? If so, the obvious solution would be to change the datamodel server side.
If not, I would suggest storing the initial response in a mutable object from useRef.
Edit
const [lists, setLists] = useState([]);
const cache = useRef([]);
useEffect(()=>{
const url = "https://domain/api/all";
fetch(url).then(response => response.json()).then(response=> {
cache.current = response.json.list;
setLists(response.json.list);
});
});

Too many re-renders when accessing data from an API in React

I am making a get request to an API that is linked to my database.
dataApi is a really big object with a lot of objects and arrays nested within it.
Some of the entries from the database are not having the full details that I need so I am filtering them to only show those with a length of > 5.
Now the issue is when I try to get the name of each entry which is split into either Tag1, Tag2 or Tag3.
Before this when I was accessing all the entries and getting the items within them there was no issue.
But when I try to filter them by the name and store the objects corresponding to that name in its state this issue arrises.
Edit:
When I console.log(arr1) it shows all the data but the moment I set the state to it it causes the error.
// Data from all entries in database
const [dataApi, setDataApi] = useState();
// Data for each of the tags
const [tag1, setTag1] = useState();
const [tag2, setTag2] = useState();
const [tag3, setTag3] = useState();
useEffect(() => {
axios.get(URL).then((res) => {
const data = res.data;
setDataApi(data);
});
}, []);
const getTagDetails = data => {
const arr1 = [];
const arr2 = [];
const arr3 = [];
data &&
data.forEach(d => {
// Entries into the database which do not have any tag information
// have a size of 5 and those with all the details have a size of 6
const sizeOfObject = Object.keys(d).length;
// Only need database items with all the details
if (sizeOfObject > 5) {
const name = d["tags"]["L"][0]["M"]["name"]["S"];
// Split the data for the tags into their respective name
// Will be used to set individual datasets for each tag
if (name === "Tag1") {
arr1.push(d);
}
if (name === "Tag2") {
arr2.push(d);
}
if (name === "Tag3") {
arr3.push(d);
}
}
});
setTag1(arr1);
setTag2(arr2);
setTag3(arr3);
};
getTagDetails(dataApi);

I guess the problem is you call getTagDetails(dataApi) inside of file so it causes this infinite rendering problem
Instead remove getTagDetails and try to call this functions after API resolved.
useEffect(() => {
axios.get(URL).then((res) => {
const data = res.data;
getTagDetails(data)
});
}, []);

I think your problem is the way you have structured your getTagDetails function. Each time you render, you call getTagDetails() and the first thing you do is create a new array for each tag. When you call setTag with the new array, it will rerender. You'll probably want to move the getTagDetails logic into the effect so it only runs once on mount (or add a dependency to the dependency array if you need to update on new data)

Bind event handler to document & have access to firebase api data via useEffect

Quick version:
My ultimate goal is to do something like the link below but with an async call to firebase per useEffect where the list data is composed of firebase object content.
https://codesandbox.io/s/usage-pxfy7
Problem
In the code below useEffect encapsulates code that pings firebase and gets some data back called "clients". The data is retrieved perfectly.
I then store that data using useState to two different instances of useState. The data is stored at clientList and clientListForRender.
So far so good.
Now the problem starts.
I have a third instance of useState that takes a number. I want to set a keypress event to the document so that I can use the up/down arrows to toggle the counter and access each value of the clientListForRender array.
When I set the eventListener I do not have access to the array (presumably due to the async calls not being in an order that allows for it).
I am not sure how to write my hooks in a way that gives me the result I want.
Thank you.
const clientsRef = firebase.database().ref('clients');
const [clientList,setClientListState] = useState([]);
const [clientListForRender,setClientListStateForRender] = useState([]);
const [selectedIndex, updateSelectedIndex] = useState(0);
useEffect(() => {
function handleKeyPress(event,arr){
console.log(arr)
if(event.key === "ArrowDown"){
updateSelectedIndex((prev)=>{
return prev += 1
});
}
}
clientsRef.on('child_added', snapshot => {
const client = snapshot.val();
client.key = snapshot.key; // __________________________1. get firebase data
setClientListState(function(prev){
setClientListStateForRender(()=>[client,...prev]); //_______2 store data
// document.addEventListener('keydown', handleKeyPress); <---I am not sure where to put this. I have experimented and
// I decided to omit my cluttered "experiments" to protect your eyes
return[client,...prev]
});
});
},[]);

Ok there are few issues with the code you posted:
1) You should definitely not add your keyboard listener in the child_ added listener ( this means that every time the child_added listener is called, you are going to create a new listener, leading to unexpected results and memory leak)
2) You are calling setState in a setState updater function (the callback function you provided for, setClientListState), which is an anti pattern and makes your code hard to follow and understand, and will cause unexpected effects once the component grows. If you want to update a state based on a previous state then use the useEffect callback
3) the useEffect function takes a second parameter, called array of dependencies. When you have provided it with an empty array, it means that you want your effect to run only once, which is problematic because we see that the function depends on clientsRef variable. ( from this actually comes your problem because the keyboard listener was having the old value of your clientsList which is the empty array, and so it was always returning 0, when keys where pressed, i explained more in the code sandbox)
4)You should return a callback function from the useEffect function to clean the effects you created, turning off the listeners you attached (or else you might have memory leaks depending on how much the component gets mounted/unmounted)
ok here is how the code should be to work:
const clientsRef = firebase.database().ref('clients');
const [clientList, setClientListState] = useState([]);
// I don't understand why you wanted another list, so for now i only use on list
// const [clientListForRender,setClientListStateForRender] = useState([]);
const [selectedIndex, updateSelectedIndex] = useState(0);
useEffect(() => {
function handleKeyPress(event, arr) {
if (event.key === 'ArrowDown') {
updateSelectedIndex(prev => {
if (prev >= clientList.length - 1) {
return (prev = 0);
} else {
return prev + 1;
}
});
}
}
clientsRef.on('child_added', snapshot => {
const client = snapshot.val();
client.key = snapshot.key; // __________________________1. get firebase data
setClientListState(function(prev) {
return [client, ...prev];
});
});
document.addEventListener('keydown', handleKeyPress);
// here you should return a callback to clear/clean your effects
return () => {
document.removeEventListener('keydown', handleKeyPress);
clientsRef.off();
};
// Its important to add these here, or else each time your keyboard listener runs it will have the initial value of
// clientsList ([]), and so clientsList.length = 0, and so you will always updateSelectedIndex(0)
}, [clientList, clientsRef]);
//here render based on selected list as you wish
Finally i have set up a working codesandbox that emulated data fetching based on the example you give https://codesandbox.io/s/usage-4sn92, i added some comments there to help explain what i said above.