In this blog post, we will explore how to implement drag and drop functionality using the React framework, along with the Suspense feature introduced in React 16.6. Drag and drop is a commonly used user interface pattern that allows users to intuitively move elements on a page by clicking and dragging them.

Table of Contents

• Introduction
• Setting Up the Project
• Implementing Drag and Drop
• Using Suspense to Enhance Performance
• Conclusion

Introduction

Drag and drop functionality can be a complex feature to implement, but with React, we can create reusable components that handle the drag and drop behavior. We will be using the HTML5 drag and drop API which provides the necessary events and methods for implementing this functionality.

Setting Up the Project

First, let’s set up a new React project by running the following commands:

npx create-react-app drag-and-drop-suspense
cd drag-and-drop-suspense

Next, let’s install the required dependencies:

npm install react-dnd react-dnd-html5-backend

Implementing Drag and Drop

To implement drag and drop functionality, we’ll need two components: a draggable component and a droppable component. The draggable component will be the one that can be moved around, and the droppable component will be the target area where the draggable component can be dropped.

Let’s start by creating the draggable component:

import React from 'react';
import { useDrag } from 'react-dnd';

const DraggableItem = ({ item }) => {
  const [{ isDragging }, dragRef] = useDrag({
    item: { type: 'item', ...item },
    collect: monitor => ({
      isDragging: monitor.isDragging(),
    }),
  });

  return (
    <div
      ref={dragRef}
      style=
    >
      {item.name}
    </div>
  );
};

export default DraggableItem;

In this draggable component, we are using the useDrag hook from the react-dnd library to handle the drag behavior. The useDrag hook returns a dragRef that needs to be attached to the component you want to make draggable. We also define the item object that will be passed to the droppable component.

Now let’s create the droppable component:

import React from 'react';
import { useDrop } from 'react-dnd';

const DroppableArea = ({ onDrop }) => {
  const [{ isOver }, dropRef] = useDrop({
    accept: 'item',
    drop: onDrop,
    collect: monitor => ({
      isOver: monitor.isOver(),
    }),
  });

  return (
    <div
      ref={dropRef}
      style=
    >
      Drop here!
    </div>
  );
};

export default DroppableArea;

In the droppable component, we are using the useDrop hook to handle the drop behavior. The useDrop hook accepts an accept prop to specify which type of items can be dropped in this component. In the onDrop function, we can handle what happens when an item is dropped.

Using Suspense to Enhance Performance

React Suspense allows us to handle async operations, such as loading resources, and suspend rendering until the data is ready. In our case, we can use Suspense to lazy load the drag and drop components only when needed.

First, let’s wrap our main component with the Suspense component and define a fallback component to show while the drag and drop components are loading:

import React, { Suspense } from 'react';
import DraggableItem from './DraggableItem';
import DroppableArea from './DroppableArea';

const App = () => {
  return (
    <div>
      <Suspense fallback={<div>Loading...</div>}>
        <DraggableItem item= />
        <DraggableItem item= />
        <DroppableArea onDrop={() => console.log('Item dropped!')} />
      </Suspense>
    </div>
  );
};

export default App;

By wrapping our components with the Suspense component, we can now benefit from lazy loading. The fallback component will be shown until the drag and drop components are loaded.

Conclusion

In this blog post, we have learned how to implement drag and drop functionality using the React framework, along with the Suspense feature. Drag and drop can greatly enhance the user experience of our applications, making it easier for users to interact with elements on a page. By using Suspense, we can also improve the performance of our application by lazy loading components only when needed.

Happy dragging and dropping! 👋

References:

• React DnD Documentation: https://react-dnd.github.io/react-dnd/
• React Suspense Documentation: https://reactjs.org/docs/react-api.html#reactsuspense