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reactjsaxios

How to make cancel-able API call in event conforming to React Strict Mode


I'm hopelessly trying to find a way to send, receive and process an API request in React component, but executed from within an event handler, not directly in useEffect. The requirements are:

  • Using Axios to easily send async requests
  • The request needs to be cancelled when React component unmounts
  • I want this solution to work in strict mode (sending two requests will be fine, but it would be cool if someone shown solution for a single request only)

My current approach suffers from the dreaded auto-cancelling of the request, because the AbortController needs to be instantiated in the root scope of the component (otherwise it will not be reachable both from useEffect cleanup function and from the event handler.

The sekeleton component looks like following:

import { useState, useEffect } from 'react'
import { Button } from 'react-bootstrap'
import { ServiceContainer } from '../../../services/ServiceContainer.ts'

function Login(props: { serviceContainer: ServiceContainer }) {

    const [ email, setEmail ] = useState("");

    const abortController: AbortController = new AbortController();

    function onSuccess() {
        // Do sth
    }

    function onFailure() {
        // Do sth else
    }

    function onButtonClick() {
        
        // This calls Axios internally
        props.serviceContainer.ApiClient.SomeAction(email, abortController, onSuccess, onFailure);
    }

    useEffect(() => {
        return (() => {
            abortController.abort();
        });
    });

    return(
        <Button onClick={onButtonClick}>Click me!</Button>
    );
}

export { Login }

The code above is doomed to fail in Strict Mode, because the abortController.abort() will get called immediately and prevent request from being sent in the first place.

These are potential solutions and workarounds I thought of:

  • Constructing new AbortController each time button is clicked, per each request. I have no idea on how to do it though.
  • Moving AbortController inside useEffect, what usually solves the problem. However, it won't be reachable from the onButtonClick anymore.
  • Extracting the whole request part into separate component. I'd need to pass through props all required parameters (email in the above example) and a way to send back a callback about the result (possibly a set* function? Or an actual callback method created via useCallback()?)
  • Replacing changing state of the component (Enter-Request-Success/Failure) into routing and switching between components (but then passing data will be tricky).

Is there a canonical way of making API calls OUTSIDE the useEffect "component constructor"?


Solution

  • One way would be to make your request from within an Effect triggered by a state change.

    function YourComponent() {
    
      const [fetching, setFetching] = useState(false);
    
      const onSuccess = useCallback((data) => {
        setFetching(false);
        // ...
      }, [])
    
      const onError = useCallback((err) => {
        setFetching(false);
        // ignore abort errors
        if (err instanceof DOMException && err.name == "AbortError") return;
        // do some logging
      }, [])
    
      function onButtonClick() {
        setFetching(true);
      }
    
      useEffect(() => {
        if (!fetching) return;
        const controller = new AbortController();
        apiContext.requestSomething(controller, onSuccess, onError);
    
        return () => {
          controller.abort();
        };
      }, [apiContext, fetching, onSuccess, onError]);
    
      return (
        <button onClick={onButtonClick}>Click me!</button>
      );
    }