Fixing Hydration Errors in Next.js 14 with Shadcn Dialog Component

Hydration errors in Next.js can be frustrating, especially when working with complex UI libraries like Shadcn. If you’ve encountered the error:

Error: Hydration failed because the initial UI does not match what was rendered on the server.

This guide will help you understand the cause and provide practical solutions to resolve the issue.

The Problem

The primary cause of this error in your Next.js application is mismatched DOM structure between the server-rendered HTML and the client-rendered React components. Specifically, using Shadcn’s SheetTrigger component with a nested Button creates invalid HTML:

<button>
  <button></button>
</button>

This violates HTML specifications and results in hydration errors. This issue occurs because both SheetTrigger and Button render <button> elements by default.

The Solution

1. Use asChild Prop for SheetTrigger

Shadcn’s SheetTrigger component, built on Radix UI, includes an asChild prop. Setting this prop allows you to use a custom component (like Button) without rendering an additional DOM element.

Updated Code:

import {
  Sheet,
  SheetContent,
  SheetDescription,
  SheetHeader,
  SheetTitle,
  SheetTrigger,
} from '@/components/ui/sheet'
import { Button } from '@/components/ui/button'
import Link from 'next/link'

export default async function JobUI({ params }: { params: { slug: string } }) {
  const data = await getData(params.slug)

  return (
    <div className="flex gap-3">
      <ImageGallery images={data.images} />

      <Sheet>
        <SheetTrigger asChild>
          <Button>View Information</Button>
        </SheetTrigger>
        <SheetContent className="w-96">
          <SheetHeader>
            <SheetTitle className="mt-5">
              <p>{data.name}</p>
              <p className="text-orange-500">Category: {data.categoryName}</p>
            </SheetTitle>

            <SheetDescription>
              <p className="text-sm font-bold">Description</p>
              <p>{data.description}</p>
            </SheetDescription>

            <SheetDescription>
              <p className="text-sm font-bold">Objective</p>
              <p>{data.objective}</p>
            </SheetDescription>

            <Link href={data.link} target="_blank">
              <Button>Project Link</Button>
            </Link>
          </SheetHeader>
        </SheetContent>
      </Sheet>
    </div>
  )
}

Why asChild Works

Using asChild prevents SheetTrigger from rendering its default <button> element. Instead, it passes all functionality and behavior to the Button component, avoiding nested <button> tags.

2. Avoid Suppressing Hydration Warnings

Some developers use suppressHydrationWarning={true} as a quick fix. While this suppresses errors, it does not resolve the root cause and can lead to unintended side effects. Avoid this approach unless absolutely necessary.

3. Debugging Other Components

If you’re using other Radix components (e.g., Tooltip, Tabs), similar issues might arise. Always check for nested DOM elements and use the asChild prop where applicable.

Example with TabsTrigger:

<TabsTrigger asChild>
  <Button>Tab 1</Button>
</TabsTrigger>

Additional Tips

Validate Server-Side and Client-Side Rendering

Ensure your components render identical HTML on the server and client. Use Next.js’s useEffect to handle client-only logic when needed.

Example:

import { useEffect, useState } from 'react'

const ClientOnlyComponent = () => {
  const [isClient, setIsClient] = useState(false)

  useEffect(() => {
    setIsClient(true)
  }, [])

  if (!isClient) return null

  return <div>Client-only content</div>
}

Conclusion

Hydration errors in Next.js, especially with Shadcn components, can be resolved by understanding the underlying issues with nested DOM elements. By leveraging the asChild prop and ensuring consistent server and client rendering, you can create seamless and error-free applications.

Key Takeaways

• Use asChild to avoid invalid nested DOM structures.
• Avoid suppressing hydration warnings without fixing the root cause.
• Validate your components for consistent server and client rendering.

Following these practices ensures your Next.js application works flawlessly with Shadcn UI components.