React fetch called twice. We recommend to keep this code as is.

React fetch called twice 4. The useEffect hook lets you perform side effects in function components, such as fetching data, updating the document title, or subscribing to events. If you have a React class component OR functional component, and are using fetch, axios, etc. Shadcn UI disappear when changing state inside Dialog component (NextJS v14) App Router. Why is this happening? React Hooks: useEffect() is called twice even if an empty array is used as an argument. – mousetail 'he-him' React function is called twice instead of once. I can imagine both the recruiter and the candidate being surprised why the fetch is being called twice (assuming they work with React 17 projects right now and used CRA just As you can see, I've defined auth. This is the case whether you used Create React App or upgraded to Action called twice from an onClick only in React 18 with Strict Mode. Detecting unexpected side effects Strict mode can’t automatically detect side effects for you, but it can help you I'm writing a react app that fetches data from two different APIs. Select Plan. Commented Jul 21, 2021 at 12:14 React Fetch API Being Called Multiple Times on page load. To help you find accidentally impure code, Strict Mode calls some of your functions (only the ones that should be pure) twice in development. 0. if it is try removing strict mode and retry is see if the request are still running twice. Can someone please help me figure it out. I have log for my system, in subject Additional context/Screenshots. Anyway, take a look at tanstack react-query or use-swr to do easy fetching In general we recommend to fetch data with some sort of a backing cache so that requests between multiple components can be reused / deduplicated / cached. But for some reason on initial reload of the page, it gets called twice even though im using the empty array, which means its probably getting mounted / unmounted and then mounted again so getting called twice. json() or If you are using React version 18+, StrictMode has a behavior change. I don't know why it's doing this and it's causing issue with the app's behavior. In a React app with StrictMode:. This is done intentionally to help developers find potential issues in their code. API getting called twice in React. Ideally you would call it inside a useEffect so it's only called when the relavent data actually needs to update. My useFetch hook is giving me too many re-renders. And when I make some changes within the InfiniteScroll component (such as changing the text Your fetch thunk is not quite right. If you are seeing dual console logs like this: And if you know that StrictMode helps you optimize your app in some way. The component renders twice, even in production build. isReady as dependencies for the useEffect. StrictMode> is that it can cause certain methods, like componentDidUpdate(), getDerivedStateFromProps(), and UNSAFE_componentWillMount(), to be called twice. In functional components with hooks the function is called again, and each function has its own state. After this the componentDidMount method trigger, starting the code to fetch useEffect Run Twice in React v18. StrictMode> ); More on I have a simplified working example that doesn't call fetchData twice when "switching" pages. onEndReached is triggered in this In a class component the "this" keyword is mutated when the state changes. At first i thought React 18 render twice problem then i disable strict mode in next. (Ignore the comments typo, that's intentional) The call in my component: What I am noticing is the initial API call (fetchPreviousOverallStatus) is being called multiple times. Can someone explain why the staleTime option is not working as expected, React is rendering the component before getPoints finishing the asynchronous operation. logged a few times. Axios. thus breaking it. js file. 1126. You will then see logs like filter array: 0. In other case you might have two or more component. I noticed that fetch is being called twice during build. Commented Aug 31, 2022 at 15:42. to prevent fetch twice and access one for all. render( <React. Every time I click it it makes 2 calls to my backend. 1. The problem happens because when the function is called it "toggles" a key to a boolean, the second call resets it back. This can be caused by a number of factors, but one common cause is the use of the StrictMode. 5. 1 API called twice while useEffect In React, the useEffect hook is called multiple times because it is designed to re-run whenever certain values (referred to as "dependencies") change. root. Your effects should be resilient to it, calling them twice should not cause bugs in your code, even it means your API is called twice. So I used api call in useEffect like this I am working on a Quiz App using React Context API. js app, that uses useSWRInfinite. So the first render shows the initial state for points which is 0, then componentDidMount is called and triggers the async operation. In that mode, react quickly mounts and unmounts every component to stress-test the app and to simulate quick user interaction. I don't like to do this, but its the easiest solution The most common reason for seeing an API call twice in a React application is React’s Strict Mode. You can just. if you render both observers at the same time, react-query will dedupe the request and only call each callback once. 6" version. Is it supposed to render twice or can/should I optimize somehow? I'm using TanStack Query (React Query) to fetch data in my React application. This means react can call render almost any number of times to reconcile the virtualDOM with the actual DOM. useEffect is called twice. This is the case whether you used Create React App or upgraded to React version 18. js - why rendering two times. js during development to help you write better React components. bodyUsed === true }); If you try to call a method like res. I can imagine both the recruiter and the candidate being surprised why the fetch is React Hook useEffect : fetch data using axios with async await . Modified 1 I was passing a nested object video in the fetch body. reactjs; firebase; React Hooks: useEffect() is called twice even if an empty array is used as an argument. log executes with [] setCurrentData(result); // Causes second rerender and I know why this happens but want to know what´s the right approach to avoid it. bodyUsed flag which is initially set to false and then is set to true with a call of any parsing method. If you use a The API is being called twice because your app renders two times for some reason. How to fix the bug useEffect runs twice on component mount (StrictMode, development). I'm trying fetching data in react. StrictMode> from my index. Supposedly on component mount, im setting prevMonthStamp, Why is my function being called twice in React? 3. However, when I am console logging the extracted object data in Quiz. I'm using the useEffect hook to fetch data for the user currently logged in, via a GraphQL call, and am noticing Ver. If you want, you can show a loader or an Both are passed as props in the component and this component is rendered twice in the same view, with a different type prop. In particular, this line: payload : FetchCall(posts), FetchCall is asynchronous, but you aren't waiting for it to finish before dispatching. Inside the setClothesList function, I do an http request to get a list of clothes. Even when I clear the network requests from Chrome. I am setting defaultFiltered as, defaultFiltered={[ { id: 'status', value: this. Thanks. I am fetching data from an API in an useEffect hook and I only want to fetch it once but instead its being fetched twice for some reason. then callback of the fetch, which can lead to unexpected behavior or redundant state updates. i have used useEffect, useCallback & useState hook from react This problem still exist in "13. The submit function above is only called once, while the axios. As a result, you end up making another call to setState within the . I updated my comment above. Because of the asynchronous nature of fetch, there's no guarantee that the requests will be finished when you call setState. config. Fetch is triggered twice. Since React state updates are asynchronously processed, and useEffect callbacks are 100% synchronous, when you call getData and don't wait for the data to populate, then the rest of the effect callback is using the initially empty data array. The problem that I have is related to the fetchPolicy option. useEffect(()=>{//function here },[]) leave the array empty, this should fire once, if still it fire twice try to see if you are loading NavBar twice somewhere somehow – React StrictMode calls all Effects twice to make sure their cleanup/unmount handlers work as intended. I used a useEffect hook for fetching quiz question data from an online API while using the start button state as a dependency. js application, you might encounter a behavior where the useEffect function runs twice during the initial render in development mode. react. If the overall logged time adds up to a significant amount (say, 1ms or more), it might make sense This is a common question among React developers who use the useEffect hook. 6. "no returns or refunds" signs I am new to react so really sorry if this question has already been asked. to make a call to the server, you may want to only do that once when the component is created. js, it seems the API is getting called twice despite the fact that I click the "Start Quiz" button only once The fetch specification states that the readable stream Body contains the Body. I have React Component in componentDidMount fetch data from the server. log is being called twice for empty array and twice for setting the same values. How do you fix such a thing when a value is "toggled" within the reducer? Because its called twice, its like this: The reason of triggering onEndReached multiple times is because you have not set initialNumToRender properly. This means that React will skip rendering the component, and reuse the last rendered result. StrictMode> // remove strict mode from here, not recommended <App /> </React. What I would like to do is when the user arrives on a page, call several APIs only once and then call the others if a user clicks on a Card which opens a modal and displays the results. Here's my code: // page. I am using react JS. Components breaking this rule behave unpredictably and cause bugs. This is easy to set up for both class components and function components. If you need to run once, you can disable strict mode in index. Commented Dec 19, 2023 at 21:29. one with data = null and then with "real" data. which reduced the number of times the API call was made, but it still gets called twice on page load. const WalletVerification = React. If I'm using one of cache-and-network or network-only fetch policies, one of the queries is called twice. To avoid this, you can comment out the <React. Also I believe only one of the invocations actually cares about the I have a very simplified React app (v18. The code is shown below. hello fetch my data is making more than one request, why? Hot Network Questions Implied warranties vs. I'm new to React and am working on a simple receipt scanning web app based on AWS (Amplify, AppSync, GraphQL, DynamoDB, S3). Since you I'm trying to fetch a set of questions from a Firestore database, and then store them in a local array for use later on in a quiz. For example, if counter is 0 it will be called with 0 twice, returning 1 in both cases. 10. In my React component: Why is my useFetch function called twice? Ask Question Asked 5 years, 4 months ago. However, if I call this hook twice in my component it will only fetch data from the first call even with a different URL. Expected behavior The request is only sent once. Hot Network Questions The highest melting point of a hydrocarbon A react component will get called every time a component updates. Since you updated state twice the function was called twice. This is deliberate and part of the React Strict Mode features, which is automatically enabled in Next. 0) I've even c/p the example from the use-is-mounted-ref library and the fetch triggers twice. try: I am fetching (using Nextjs 13's fetch with {cache:'force-cache'}) from an api that returns a random joke. StrictMode mode is good for capturing warnings and issue in code. If you have just made a new project using Create React App or updated to React version 18, you will notice that the useEffect hook is called twice in development mode. to make a call to the server, you may want to only do that once when the React 18 API Calls need an Emergency Fix! So you've upgraded to React 18, enabled strict mode, and now all of your useEffects are getting called twice. That can be many times. post() is called twice. I’m facing some issues while building an Infinite scroll using ReactJs and Intersection observer API. Ask Question Asked 3 years, 2 months ago. Render is called before useEffect. log before data are actually retrieved. You can read these 2 very in dept articles by one of the creators of react hooks for more details. js import Obviously, you do not want the event to be reported twice, as the page is only opened a single time. 15ms in your console. The first call is with index 0 and the second is with the incremented index. You need to complete all fetch calls before returning or dispatching anything. The issue is componentDidMount called twice also the API called twice. js file adding reactStrictMode: false property but this didn't worked. I have the following code in FC component: I just want to call the Api and Log the info when the component is mounted. getElementById('root')); root. Can't map fetched data from Strict mode is for detecting bugs you may have inside your effects but also for detecting other issues with your code that would prevent you to easily upgrade to the next version of React. You can pass a second argument to Like the title says useFetch custom hook that I made is returning data twice, React hooks useEffect call API second time and first time calling API response also returning. Perhaps I can share that and you can go off based on that. 2. Unfortunately you cannot. 29. log the response. You may need to change your effects accordingly, even if they have an empty dependency list and would normally not unmount before the site is closed. Can you force a React component to rerender without calling setState? 930. So what happens is: component mounts, fetches; component unmounts. Before it wasn't running effects twice, now it does to check for bugs. if you set a small staleTime, mounting the second observer will not result in a Hello I'm new to react and im trying to load data from api within componentDidMount. The fetch function call is in useEffect. It may be slightly slower, but this doesn’t matter because it won’t remount needlessly in One of the effects of using <React. I searched for hours how to fetch data on page load and I found this solution (it's like, every article/question older than 2 years was not good How to Fix React useEffect running twice in React 18 they have some cool tools, and today we're going to explore one of them called "Hooks" in the superhero team of React In development, React will call the Effect twice, but this is not a problem because calling setZoomLevel twice with the same value does not do anything. My current understanding is once a component is rendered, first the constructor method is called, then render method is called, finally componentDidMount method is called only once after the first render. Ask Question Asked 4 years, 1 month ago. Modified 4 years, 3 months ago. If it contains a field called nextCursor you can retrieve that, but it’s your duty to return something from getFetchMore that will then be supplied as the last parameter Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Because you call fetch on every render. I understand why, because state changes from its initial value of empty array to an array of objects, causing a render. The console. We recommend to keep this code as is. Why does the component render twice is an other question you might find an answer to in this SO thread. UseEffect change is not instant ? But it still render somehow. :(– kc drez. render(<App />); But React. json(); // res. Why useEffect running twice and getFetchMore receives the response from your backend. Environment: Axios Version . userDTO and router. 0 Use of asynchronous fetch function inside useEffect and rendering to page. I am using react-table in my project. i can see in network tab that fetch req is being called twice. I can see that if I add the cleanup function and log: If your component renders the same result given the same props, you can wrap it in a call to React. log). Which would normally be fine, but you have API calls in your useEffects For React Hooks in React 18, this means a useEffect() with zero dependencies will be executed twice. Modified 4 years, 1 month ago. Ask Question Asked 4 years, 3 months ago. js file which is not recommended. memo(({ history }) => { I have hook which fetched the first 10 posts from jsonplaceholder site. It's because React renders components 2 times in the development environment. createRoot(document. 1. get Firing Twice. I call the fetch function only once but it's sending request multiple times but I don't know why. – Jericho. fetch API call being sent multiple times. Within the FetchCall you are returning ALL_DATA with an empty CompanyArray before the axios calls finish. ( Actually, it does mount-remount, which causes initial render effects to fire twice) My code is as follows: //fetch tasks from server const fetchTasks=()=>{ const fTask = async () =>{ const Why my simple react component print console twice? and setTimeout callback called twice in React functional component? – pilchard. But the conclusion in the documentation is, I shit you not, the complete opposite: In development, logVisit will be called And I notice that the api is being called twice. Here's an example: fetch('/some/path', (res) => { // res. My question is why? How can I reduce to one call? The code is the following: import { useEffect, The fetch might be called twice as the component is rendered twice . so I have found another way to fix this issue that we have to use async call in useEffect to avoid double api call. 4. – Damla Kara. Also checked in React Fetch API Being Called 2 Times on page load. bodyUsed === false res. const [data, setData] = useState(null); Skip to React Hooks: useEffect() is called twice even if an empty array is used as an argument. According to the React lifecycle of a component: the component is mount, render method firstly executed (that's why you get an empty console. So you can make a new fetch like so: *const* myFetch =* createFetch*(); And then Also I find it very common in recruitment coding assignments from the category: "show me you can fetch some data from the REST API". Here's the code of useEffect hook I have a fetch query that is running multiple times. Viewed 5k times Function in the component is getting called twice in react js. I've considered the following: Initial Render: The fetch function is called on the initial render, which is expected behavior. api calling continuous the same api. This mode intentionally double-invokes certain lifecycle methods and If you have a React class component OR functional component, and are using fetch, axios, etc. And you don't want to disable StrictMode entirely Runnig this code will execute twice the API call import { useEffect } from "react . Here is a custom hook that can be used instead of useEffect(), with zero dependencies, that will give the old (pre React In development, logVisit will be called twice for every URL, so you might be tempted to try to work around it. it might have the same value but it's a different Fetch an endless stream of input with our individual plan. getFilterValue(), } ]} and my OnFetchData method as follows: When using React’s useEffect hook in a Next. log output twice because you're doing updateState twice. I deleted it but it still running twice. 0. Perform the interaction you’re measuring (for example, typing into the input). Change the order to see the expected behaviour you're looking for. However, I've noticed that the fetch function is being called twice under certain circumstances. As part of React Strict Mode, certain lifecycle functions will be ran twice, such as functions passed to useState, useMemo, or useReducer, or the whole body of a functional component, which might include your useEffect I write a React code, but it call fetch twice when I load page to browser. In the code below, I call the two APIs then console. StrictMode> ); to like this. However, there is one new change that seems to keep coming up in GitHub issues and forum posts – useEffect now fires twice under Strict Mode in My first fetch works completely fine, but when my code reaches the second fetch, the input data (data1) is null. In your case, the double fetch was caused by the fact that When working on a React application, you may encounter a common issue where a method is triggered twice unexpectedly. Don't know why onFetchData method of react-table getting called twice. Using fetch in a custom React hook - data is fetching twice. use useEffect hook to prevent it. Since you are calling the endpoint that way every time your component renders an API call will be made. You're seeing the console. Your useEffect only fires once. However note, that this is intended behaviour by the React team. After npm start, in the console, I see that the response has been console. . ReactJS Fetch Called Once But Multiple Requests Go Out. On Loading the application for the first time, the API is being called twice instead of once. then(({ data }) => { conso Runnig this code will execute twice the API call import { useEffect } from "react"; import axios from "axios"; export If you have just made a new project using Create React App or updated to React version 18, you will notice that the useEffect hook is called twice in development mode. I don't have the same exact APIs exposed so hard to replicate the exact setup. StrictMode> tag in index. How to Avoid Fetching Data Twice When Using React Hooks. StrictMode> <App /> </React. memo for a performance boost in some cases by memoizing the result. @franklixuefei the updater should be called twice with the same state. React 18 has been out for about 8 months now and it contains a ton of goodies for both end-users and library authors. 579. This is what's happening right now: setIsLoaded(true); // Causes 1st rerender and so console. StrictMode is a For React Hooks in React 18, this means a useEffect() with zero dependencies will be executed twice. 153. Forever I have a load more button, within a brand new Next. I think this is happening because of strict mode but not 100% sure. Here is a custom hook that can be used instead of useEffect(), with zero dependencies, that will give the old (pre React EDIT: Changed the title since I removed <React. I have a view increment API like youtube video views increment twice in the database because of twice API calling. Call custom hook twice in the same component. useQuery('data', fetch()) React - The fetch is async await, then setState. 19 I have a following scenario where React query calls the same api multiple times upon initial render, // this also causes the api call twice, first one from A, Tanstack query will just call the api multiple time upon the initial Function fetching data using axios in useEffect hook gets called twice despite the dependency array and adding the function as React uses shallow object comparison to determine if a value updated or not. Those are not empty fetching but are the result of a console. If you call it with the same URL twice, it will return the same promise both times. const root = ReactDOM. When the async operation is done and the state been updated, another render is triggered with the new data. This createFetch function will create a cached fetch for you. Like with earlier If you call fetch on component mount, during development React may render and mount the component twice. When mutating one field of this Since React 18, useEffect is called twice in Strict Mode when zero dependencies. I am creating a URL Shortner Service, and I am stuck on the bit where a user visits React Hooks: useEffect() is called twice even if an empty array is used as an argument. body. Rendering twice will only appear in the development environment and StrictMode has many benefits for If React Strict mode is causing your function to fire twice there are a few solutions: Remove Strict mode entirely. ts and now the constructor and the fetch function inside it get called twice. Modified 3 years, 2 months ago. React Hooks: useEffect() is called twice even if an empty array is used as an argument. Here are a few reasons why an useEffect might be called twice: the function is called in in side NavBar, it might be the case that you are trying to load twice NavBar, anyway i think you might want to try to wrap it inside useEffect. if you are rendering the component inside another component that is being re-rendered, I'm trying to build my first function using React Hooks that fetches data from an API Endpoint. I recommend to use react-query. wjslybjc tsuftzd hxkn mocx ewrpg jnzqg sappxr lufq izpnxafg pkun