How to Create a Custom Hook in React: A Step-by-Step Tutorial

How to Create a Custom Hook in React: A Step-by-Step Tutorial

Creating a custom hook is straightforward once you know the steps. Here is a tutorial using a real useFetch example.

Step 1: Identify the Logic to Extract

Find stateful logic you are repeating. If you fetch data in multiple components with the same loading, error, and data pattern, that is a perfect candidate for a useFetch hook.

Step 2: Name It Starting With use

Create a function called useFetch. The 'use' prefix is required so the lint plugin and readers know it is a hook.

Step 3: Move the State and Effects Inside

Move the useState calls for data, loading, and error, and the useEffect that fetches, into the custom hook. The logic is identical; it just lives in a separate function.

Step 4: Accept Arguments

Make the hook flexible by accepting arguments, like a URL. This lets the same hook serve different fetches.

Step 5: Return What the Component Needs

Return the data, loading, and error, typically as an array or object. The calling component destructures what it needs.

Step 6: Use the Hook in a Component

Call useFetch inside a component, exactly like you would call useState. The component receives the data and renders it, without the fetching logic cluttering it.

Step 7: Follow the Rules of Hooks

The custom hook must follow the rules of hooks: call hooks at the top level, not in conditions or loops. The lint plugin enforces this inside the custom hook too.

The Takeaway

To create a custom hook: identify repeated logic, name it starting with 'use', move state and effects inside, accept arguments, return what the component needs, use it in a component, and follow the rules of hooks.