Creating a custom useDraggableEffect hook for handling side effects related to draggable elements

11 Oct 2023

Introduction

In web development, draggable elements are commonly used to enable intuitive user interactions. However, handling side effects related to draggable elements can be a bit challenging. In this blog post, we will explore how to create a custom useDraggableEffect hook to handle these side effects more efficiently.

What is a Hook?

In React, hooks are functions that allow you to reuse stateful logic between components. They enable us to write reusable logic without the need for class components or higher-order components.

Why Do We Need a Custom Hook?

By default, React doesn’t provide a built-in solution for handling side effects related to draggable elements. Therefore, creating a custom hook can help us simplify and manage these side effects more effectively in our codebase.

Creating the useDraggableEffect Hook

To create our custom useDraggableEffect hook, we need to follow these steps:

Import the necessary dependencies:

import { useEffect } from 'react';

Define the useDraggableEffect function:

const useDraggableEffect = (ref, onDragStart, onDragEnd) => {
  useEffect(() => {
    const element = ref.current;

    const handleDragStart = () => {
      onDragStart();
    };

    const handleDragEnd = () => {
      onDragEnd();
    };

    element.addEventListener('dragstart', handleDragStart);
    element.addEventListener('dragend', handleDragEnd);

    return () => {
      element.removeEventListener('dragstart', handleDragStart);
      element.removeEventListener('dragend', handleDragEnd);
    };
  }, [ref, onDragStart, onDragEnd]);
};

Using the useDraggableEffect Hook:

const MyComponent = () => {
  const draggableRef = useRef(null);

  useDraggableEffect(draggableRef, () => {
    console.log('Drag started!');
  }, () => {
    console.log('Drag ended!');
  });

  return (
    <div ref={draggableRef} draggable={true}>
      Drag me!
    </div>
  );
};

Explanation

In step 1, we import the useEffect hook from React, which allows us to handle side effects.
In step 2, we define the useDraggableEffect function that takes a ref to the draggable element, as well as two callbacks: onDragStart and onDragEnd. Inside the useEffect hook, we add event listeners for the ‘dragstart’ and ‘dragend’ events.
We define separate functions handleDragStart and handleDragEnd to trigger the respective callbacks. We then attach these functions to the dragstart and dragend events of the draggable element.
We also return a cleanup function from the useEffect hook to remove the event listeners when the component unmounts.
In step 3, we demonstrate the usage of the useDraggableEffect hook in a component. We create a draggableRef using the useRef hook and pass it along with the onDragStart and onDragEnd callbacks to the useDraggableEffect hook. We then use the draggableRef to assign the ref prop to the draggable element.

Conclusion

Creating a custom useDraggableEffect hook allows us to encapsulate the side effects related to draggable elements in a reusable and manageable way. By writing a few lines of code, we can handle the complex interactions of draggable elements effectively. This helps improve the maintainability and readability of our codebase.

#draggable #sideeffects