How to call loading function with React useEffect only once

Understanding the useEffect Hook

This usage of useEffect is similar to the componentDidMount lifecycle method in class components. It allows the function to run once after the first render, optimizing your component for efficient initialization.

Creating a Custom Hook for Initial Load

To extend this approach, you can create a custom hook, we'll name it useMountEffect. This custom hook initializes functions exactly once.

const useMountEffect = (func) => useEffect(func, []);

useMountEffect(yourLoadingFunction); // Use the hook and chill
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Optimizing with useMemo, useCallback, and ConfusedCallback

Keeping function or value references stable is crucial. useMemo and useCallback can save you from unnecessary renders, they tell your effect "No need to run again, it's all still the same here."

Linting Effect Dependencies with ESLint

The eslint-plugin-react-hooks is a useful watchdog. It barks when you forget to add dependencies to useEffects array or when dependencies change too often. So, keep your linting guard dog fed and well, and it'll keep those bugs away.

Writing Proper Data-Independent Functions

Don't keep functions inside your effect if they don't depend on anything from your component. Unlike classroom seat arrangements, outside is usually the best place for them.

Toggle Effect Function with useRef

In some cases, you might want to run your function only under some conditions. useRef can act as a flag and doesn't mind re-renders:

const hasMounted = useRef(false);

useEffect(() => {
  if (!hasMounted.current) {
    hasMounted.current = true;
    yourLoadingFunction(); // Fireworks only on the first render 🎆
  }
}, []); // Still only runs once
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Building Skills on useEffect Optimization

Creating optimized components covers multiple scenarios, each can be treated as a different adventure:

• Data fetching: Use useEffect to load data after the first render. This approach effectively reduces api calls.
• Event listeners: Use useEffect to define and remove event listeners to keep your node tree clean and leak-free.
• WebSockets and subscriptions: Use effects to establish long-lived connections when the component mounts.

Each adventure requires unique tactics with useEffect and hooks for maximum performance.

Mastering Hooks Usage

Hook misuse can lead to roller coaster behavior and Monty Python class comedy bugs. You must avoid common mistakes such as calling hooks inside loops, conditions, or nested functions.