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React State / DOM Not Updating When All Items Deleted

I'm building an app with React and Firebase Realtime Database. Objects are added to an array and sent to the database.
The arrays are updated in React and the result is sent to the database.
The functionality to remove items/objects from the list works fine when there are more than one (i.e. button clicked, database, DOM and state updated immediately).
However, whenever there's one item left and you click its delete button, it's deleted from the database but the state and React DOM aren't updated - you have to refresh the page for it to be removed.
I've tried using different methods to update the database in case it triggered a different response but that didn't work - any ideas would be greatly appreciated:
import React, {useState, useEffect} from 'react'
import { Button } from "react-bootstrap";
import Exercise from "./Exercise";
import AddNewWorkout from "./AddNewWorkout";
import { v4 as uuidv4 } from "uuid";
import WorkoutComponent from './WorkoutComponent';
import AddNewExercise from "./AddNewExercise"
import { database, set, ref, onValue, update } from "../firebase"
const Dashboard = ({user}) => {
const [selectedWorkout, setSelectedWorkout] = useState();
const [workouts, setWorkouts] = useState([])
const [creatingNewWorkout, setCreatingNewWorkout] = useState(false);
const [addingNewExercise, setAddingNewExercise] = useState(false)
function selectWorkout(number) {
const selection = [...workouts].filter(workout => number == workout.id);
setSelectedWorkout(selection[0])
}
function toggleNewWorkoutStatus(e) {
e.preventDefault()
setCreatingNewWorkout(creatingNewWorkout => !creatingNewWorkout)
}
function toggleNewExerciseStatus() {
setAddingNewExercise(addingNewExercise => !addingNewExercise)
}
function writeData() {
const newWorkouts = [...workouts]
const workoutTitle = document.getElementById("workoutTitle").value || new Date(Date.now()).toString()
const workoutDate = document.getElementById("workoutDate").value;
newWorkouts.push({
id: uuidv4(),
title: workoutTitle,
date: workoutDate,
exercises: []
})
set(ref(database, `${user.uid}/workouts/`), newWorkouts )
}
function addWorkoutToListDB(e) {
e.preventDefault();
writeData(user.uid)
}
function removeWorkoutFromList(id) {
const newWorkouts = [...workouts].filter(workout => id !== workout.id);
update(ref(database, `${user.uid}`), {"workouts": newWorkouts} )
}
function addExerciseToWorkout(e) {
e.preventDefault();
if (selectedWorkout === undefined) {
alert("No workout selected")
return
}
const newWorkouts = [...workouts]
const exerciseID = uuidv4();
const exerciseName = document.getElementById("exerciseName").value
const exerciseSets = document.getElementById("exerciseSets").value
const exerciseReps = document.getElementById("exerciseReps").value
const exerciseWeight = document.getElementById("exerciseWeight").value
const exercisetTarget = document.getElementById("exercisetTarget").checked
const exerciseNotes = document.getElementById("exerciseNotes").value;
const newExercise = {
id: exerciseID,
name: exerciseName,
sets: exerciseSets,
reps: exerciseReps,
weight: `${exerciseWeight}kg`,
target: exercisetTarget,
notes: exerciseNotes,
}
for (let key of newWorkouts) {
if (key.id === selectedWorkout.id) {
if (key.exercises) {
key.exercises.push(newExercise)
} else {
key.exercises = [newExercise]
}
}
}
update(ref(database, `${user.uid}`), {"workouts": newWorkouts} )
}
function removeExerciseFromWorkout(id) {
const newWorkouts = [...workouts];
for (let workout of newWorkouts) {
if(selectedWorkout.id === workout.id) {
if (!workout.exercises) {return}
workout.exercises = workout.exercises.filter(exercise => exercise.id !== id)
}
}
const newSelectedWorkout = {...selectedWorkout}
newSelectedWorkout.exercises = newSelectedWorkout.exercises.filter(exercise => exercise.id !== id)
setSelectedWorkout(newSelectedWorkout)
update(ref(database, `${user.uid}`), {"workouts": newWorkouts} )
}
useEffect(() => {
function getWorkoutData() {
const dbRef = ref(database, `${user.uid}`);
onValue(dbRef, snapshot => {
if (snapshot.val()) {
console.log(snapshot.val().workouts)
setWorkouts(workouts => workouts = snapshot.val().workouts)
}
}
)
}
getWorkoutData()
},[])
return (
<div>
{creatingNewWorkout && <AddNewWorkout addWorkoutToListDB={addWorkoutToListDB} toggleNewWorkoutStatus={toggleNewWorkoutStatus} /> }
<div id="workoutDiv">
<h2>Workouts</h2><p>{selectedWorkout ? selectedWorkout.title : "No workout selected"}</p>
<Button type="button" onClick={toggleNewWorkoutStatus} className="btn btn-primary">Add New Workout</Button>
{workouts && workouts.map(workout => <WorkoutComponent key={workout.id} removeWorkoutFromList={removeWorkoutFromList} selectWorkout={selectWorkout} workout={workout}/> )}
</div>
<div>
<h2>Exercise</h2>
{addingNewExercise && <AddNewExercise selectedWorkout={selectedWorkout} addExerciseToWorkout={addExerciseToWorkout} toggleNewExerciseStatus={toggleNewExerciseStatus}/> }
<Button type="button" onClick={toggleNewExerciseStatus} className="btn btn-primary">Add New Exercise</Button>
{selectedWorkout && selectedWorkout.exercises && selectedWorkout.exercises.map(exercise => <Exercise removeExerciseFromWorkout={removeExerciseFromWorkout} key={exercise.id} exercise={exercise}/>)}
</div>
</div>
)
}
export default Dashboard
If it helps, the data flow I'm working to is:
New array copied from state
New array updated as necessary
New array sent to database
Database listener triggers download of new array
New array saved to state
I have tried to use different methods (set, update and remove) in case that triggered the onValue function.
I have also tried to send null values and deleting empty nodes if the array that will be sent to the db is empty.
The above methods didn't have any impact, there was still a problem with the last array element that was only resolved by refreshing the browser.
I have tried to remove the array dependency and add the workout state as a dependency, resulting in the following error: "Warning: Maximum update depth exceeded. This can happen when a component calls setState inside useEffect, but useEffect either doesn't have a dependency array, or one of the dependencies changes on every render."

I think I understand where the issue was:
In the useEffect call, I set up the state to only be updated if the value in returned from the database was null (to prevent an error I ran into). However, this meant that state wasn't being updated at all when I deleted the last item from the array.
I appear to have fixed this by adding an else clause.
useEffect(() => {
function getWorkoutData() {
const dbRef = ref(database, `${user.uid}`);
onValue(dbRef, snapshot => {
if (snapshot.val()) {
console.log(snapshot.val().workouts)
setWorkouts(workouts => workouts = snapshot.val().workouts)
} else {
setWorkouts(workouts => workouts = [])
}
}
)
}
getWorkoutData()
},[])
`````

Why does my component fail to construct Url?

I'm fairly new to React development and hope someone can help me with this problem. I'm coding along with a YouTube video https://www.youtube.com/watch?v=XtMThy8QKqU&t=10138s (2:55:00 shows what it is supposed to do)and for some reason I can't find the mistake I'm making. When I test my app on localhost the window in which the trailer is supposed to play is only displayed when I click certain movie covers but not when I click on others. my other problem is that it will never actually play a trailer. The console displays the error you can hopefully see here [1]: https://i.stack.imgur.com/vC6Sh.jpg
import movieTrailer from "movie-trailer";
import React, { useEffect, useState } from "react";
import YouTube from "react-youtube";
import axios from "./axios";
import "./Row.css"
const base_url = "https://image.tmdb.org/t/p/original/";
function Row({ title, fetchUrl, isLargeRow }) {
const [movies, setMovies] = useState([]);
const [trailerUrl, setTrailerUrl] = useState("");
//A snippet of code which runs based on a specific condition or variable
useEffect(() => {
// if brackets are blank [] it means run once when row loads, and don't run again
async function fetchData() {
const request = await axios.get(fetchUrl);
// console.log(request.data.results);
setMovies(request.data.results)
return request;
// async function fetchData() {
// try{
// const request = await axios.get(fetchUrl);
// console.log(request);
// return request;
// }
// catch (error){
// console.log(error);
// }
}
fetchData();
}, [fetchUrl]);
const opts = {
height: '390',
width: '100%',
playerVars: {
// https://developers.google.com/youtube/player_parameters
autoplay: 1,
},
};
//console.log(movies);
const handleClick = (movie) => {
if (trailerUrl){
setTrailerUrl('');
} else {
movieTrailer(movie?.name || "")
.then ((url) => {
const urlParams = new URLSearchParams(new URL(url).search);
setTrailerUrl(urlParams.get("v"));
}).catch(error => console.log(error));
}
};
return(
<div className="row">
<h2>{title}</h2>
<div className="row__posters">
{movies.map(movie => (
<img
key={movie.id}
onClick={() => handleClick(movie)}
className= {`row__poster ${isLargeRow && "row__posterLarge"}`}
src={`${base_url}${isLargeRow ? movie.poster_path : movie.backdrop_path}`} alt={movie.name}/>
))}
</div>
{trailerUrl && <YouTube videoId="{trailerUrl}" opts={opts} /> }
</div>
)
}
export default Row

Invalid property name in movie
Taking a look at the tmdb docs it will show you what the properties of each object has. In this case, there is no name. Try using something like movie.title
In your handleClick() function you could use movie?.title.
Trying to use movie.name will give back a null value. Which errors out movieTrailer() and you get no YouTube url back.

Create handle function like this and the call it in your return function and use however you want... mainly should be used by using onClick method

In react, how can I store data immediately if there's none and use it right away?

I'm having trouble using LocalStorage data.
I used storejs (localStorage library), therefore store.getItem equals to localStorage.getItem and store.setItem equals to localStorage.setItem.
please check my code.
const test = () => {
useEffect(() => {
const res = store.getItem('data')
// I'm trying toexecutes following code if store returns undefined.
if(!res) {
store.setItem('data', [{name:'aden', age:17}])
store.getItem('data')
}
},[])
return <></>
}
I know this code doesn't work. However, What I'm trying to do is when component mounts and there's nothing in LocalStorage, I want to immediately setItem to LocalStorage, and fetch the item right away.
However, with that code, I get nothing from the LocalStorage, It seems like I'm having misconception on lifecycle of react.
How can I solve the problem?

Try this:
import React, { useState } from "react";
const Test = () => {
const [user, setUser] = useState(JSON.parse(localStorage.getItem("user")));
const addToLocalStorage = () => {
const payload = [{ name: "aden", age: 17 }];
setUser(payload);
localStorage.setItem("user", JSON.stringify(payload));
};
return (
<>
<div>
{user?.length > 0 &&
user.map((e) => <span key={e.name}>name:{e.name}</span>)}
</div>
<button onClick={addToLocalStorage}>Add to localStorage</button>
</>
);
};
export default Test;

useEffect(() => {
const res = store.getItem('data')
// I'm trying toexecutes following code if store returns undefined.
if(!res) {
store.setItem('data', [{name:'aden', age:17}])
store.getItem('data')
}
},[])
Maybe you should type store.setItem

How to instantly display data after an API call in react hooks

I don't understand why the second line, which reads data from the props, is not displayed as instantly as the first, i would like them to be displayed instantly
I update the state when a button is clicked, which calls api, data is coming in, the state is updating, but the second line requires an additional press to display
How to display both lines at once after a call? What's my mistake?
I'm using react hooks, and i know that required to use useEffect for re-render component, i know, that how do work asynchronous call,but i'm a little confused, how can i solve my problem, maybe i need to use 'useDeep effect' so that watching my object properties, or i don't understand at all how to use 'useEffect' in my situation, or even my api call incorrectly?
I have tried many different solution methods, for instance using Promise.all, waiting for a response and only then update the state
index.js
import React from "react";
import ReactDOM from "react-dom";
import App from "./test";
ReactDOM.render(<App />, document.getElementById("root"));
app.js
import React, { useState, useEffect } from "react";
import ReactDOM from "react-dom";
const useDataApi = (initialState) => {
const [state, setState] = useState(initialState);
const stateCopy = [...state];
const setDate = (number, value) => {
setState(() => {
stateCopy[number].date = value;
return stateCopy;
});
};
const setInfo = async () => {
stateCopy.map((item, index) =>
getFetch(item.steamId).then((res) => setDate(index, res.Date))
);
};
const getFetch = async (id) => {
if (id === "") return;
const requestID = await fetch(`https://api.covid19api.com/summary`);
const responseJSON = await requestID.json();
console.log(responseJSON);
const result = await responseJSON;
return result;
};
return { state, setState, setInfo };
};
const Children = ({ data }) => {
return (
<>
<ul>
{data.map((item) => (
<li key={item.id}>
{item.date ? item.date : "Not data"}
<br></br>
</li>
))}
</ul>
</>
);
};
const InfoUsers = ({ number, steamid, change }) => {
return (
<>
<input
value={steamid}
numb={number}
onChange={(e) => change(number, e.target.value)}
/>
</>
);
};
function App() {
const usersProfiles = [
{ date: "", id: 1 },
{ date: "", id: 2 }
];
const profiles = useDataApi(usersProfiles);
return (
<div>
<InfoUsers number={0} change={profiles.setID} />
<InfoUsers number={1} change={profiles.setID} />
<button onClick={() => profiles.setInfo()}>Get</button>
<Children data={profiles.state} loading={profiles} />
</div>
);
}
export default App;
To get the data, just click GET
In this example, completely removed useEffect, maybe i don’t understand how to use it correctly.
P.s: Sorry for bad english

You don't need stateCopy, as you have it in the callback of the setState:
const setInfo = async () => {
// we want to update the component only once
const results = await Promise.all(
state.map(item => getFetch(item.steamId))
);
// 's' is the current state
setState(s =>
results.map((res, index) => ({ ...s[index], date: res.Date })
);
};

Filtering an array and then mapping it isn't displaying results with React Hooks

import React, { useState, useEffect } from "react";
import axios from "axios";
const App = () => {
let [countries, setCountries] = useState([]);
const [newCountry, newStuff] = useState("");
const hook = () => {
//console.log("effect");
axios.get("https://restcountries.eu/rest/v2/all").then((response) => {
console.log("promise fulfilled");
setCountries(response.data);
//console.log(response.data);
});
};
const filter = (event) => {
newStuff(event.target.value);
if (event.target.value === undefined) {
return
} else {
let value = event.target.value;
console.log(value);
countries = countries.filter((country) => country.name.startsWith(value));
setCountries(countries);
console.log(countries);
}
};
useEffect(hook, []);
return (
<div>
<p>find countries</p>
<input value={newCountry} onChange={filter} />
<ul>
{countries.map((country) => (
<li key={country.name.length}>{country.name}</li>
))}
</ul>
</div>
);
};
export default App;
So I have a search bar so that when you enter a few characters it will update the state and show the countries that start with the respective first characters. However, nothing is being shown when I enter input into my search bar. Also, my filter function, when I console.log my countries array which is supposed to have the countries that start with the characters I entered, it's always an empty array.

You need some changes in order to make this work:
Use two states for countries, one for the list you
get in the initial render and another for the current filter
countries.
const [countriesStore, setCountriesStore] = useState([]); // this only change in the first render
const [countries, setCountries] = useState([]); // use this to print the list
I recomed to use any tool to manage the state and create a model for
the countries ther you can make the side effect there and create an
action that update the countries store. I'm using Easy Peasy in
my current project and it goes very well.
Take care of the filter method because startsWith
method is not case-insensitive. You need a regular expression or
turn the current country value to lower case. I recommend to use
includes method to match seconds names like island in the search.
const filterCountries = countriesStore.filter(country => {
return country.name.toLowerCase().includes(value);
});
Remove the if condition in the filter in order to include the
delete action in the search and get the full list again if
everything is removed.
Just in the case, empty the search string state in the first
render
useEffect(() => {
hook();
setSearchString("");
}, []);
Replace the length in the list key. You can use the name and trim to remove space.
<li key={country.name.trim()}>{country.name}</li>
The final code look like this:
export default function App() {
const [countriesStore, setCountriesStore] = useState([]);
const [countries, setCountries] = useState([]);
const [searchString, setSearchString] = useState("");
const hook = () => {
axios.get("https://restcountries.eu/rest/v2/all").then(response => {
console.log("promise fulfilled");
setCountriesStore(response.data);
setCountries(response.data);
});
};
const filter = event => {
setSearchString(event.target.value);
let value = event.target.value;
const filterCountries = countriesStore.filter(country => {
return country.name.toLowerCase().includes(value);
});
setCountries(filterCountries);
};
useEffect(() => {
hook();
setSearchString("");
}, []);
return (
<div>
<p>find countries</p>
<input value={searchString} onChange={filter} />
<ul>
{countries.map(country => (
<li key={country.name.trim()}>{country.name}</li>
))}
</ul>
</div>
);
}

You need to wrap your hook into async useCallback:
const hook = useCallback(async () => {
const {data} = await axios.get("https://restcountries.eu/rest/v2/all");
setCountries(data);
}, []);
you are not able to mutate state countries. Use immutable way to update your state:
const filter = (event) => {
newStuff(event.target.value);
if (event.target.value === undefined) {
return
} else {
let value = event.target.value;
setCountries(countries.filter((country) => country.name.startsWith(value)));
}
};
And useState is asynchronous function. You will not see result immediately. Just try to console.log outside of any function.