Video: TS TSender UI - Providers - Full-Stack Web3 Development Crash Course

## Implementing Global Providers in Your Next.js web3 App When building complex applications, especially in web3 where interactions with wallets and blockchains are common across multiple pages, managing shared configurations and state efficiently is crucial. Repeating setup code on every page leads to redundancy and maintenance headaches. This is where the "Provider" pattern comes into play, offering a clean solution for making functionalities globally accessible. In a Next.js application using the App Router, we can leverage the root `layout.tsx` file combined with a dedicated provider component to achieve this. ### What are Providers in this Context? In React and Next.js, "Providers" typically refer to components designed to supply data, configuration, or functionality down the component tree to their descendants (children). They often utilize React's Context API under the hood. In our web3 application, we rely on several libraries that require configuration and context to function correctly: 1. **Wagmi:** Provides React hooks for interacting with Ethereum blockchains (reading data, sending transactions, etc.). It needs a configuration context provided by `WagmiProvider`. 2. **TanStack Query (React Query):** Used for managing server state, including caching blockchain data fetched via Wagmi. It requires a `QueryClientProvider`. 3. **RainbowKit:** Offers UI components and logic for connecting various wallets. It depends on both Wagmi and its own `RainbowKitProvider` to manage connection state and display modals. Instead of setting up these providers individually on every page that needs wallet connectivity or blockchain interaction, we wrap our entire application with them once. ### The Component Wrapping Pattern The core mechanism involves wrapping child components with provider components. Any component rendered *inside* a provider gains access to the context or features that the provider offers. This is facilitated by React's `children` prop. A parent component renders `{props.children}`, which represents whatever components or elements were passed between its opening and closing tags. ### Centralizing Providers with `layout.tsx` and `providers.tsx` In the Next.js App Router, `src/app/layout.tsx` acts as the root layout, serving as a template for all pages within that segment. This makes it the perfect place to instantiate providers that need to be available globally. **1. Root Layout (`src/app/layout.tsx`)** The root layout imports a custom component, conventionally named `Providers`, and uses it to wrap the main page content, represented by the `children` prop. ```typescript // src/app/layout.tsx import type { Metadata } from "next"; import { Inter } from "next/font/google"; import "./globals.css"; import Providers from "./providers"; // Import the custom provider wrapper const inter = Inter({ subsets: ["latin"] }); export const metadata: Metadata = { title: "My web3 App", description: "Application demonstrating provider pattern", }; export default function RootLayout({ children, }: Readonly<{ children: React.ReactNode; }>) { return ( <html lang="en"> <body className={inter.className}> {/* The Providers component wraps the actual page content */} <Providers>{children}</Providers> </body> </html> ); } ``` Here, `{children}` will dynamically render the specific page component (like `src/app/page.tsx`) being navigated to. By wrapping it in `<Providers>`, we ensure that every page is rendered within the context of our necessary web3 providers. **2. Provider Aggregation (`src/app/providers.tsx`)** This file defines the actual `Providers` component. It imports the specific providers from the libraries (Wagmi, React Query, RainbowKit), initializes any necessary clients (like `QueryClient`), and configures them. Crucially, it also wraps its *own* `children` prop with these library providers. Remember, the `children` being passed *into* this component are ultimately the page components rendered by `layout.tsx`. ```typescript // src/app/providers.tsx 'use client'; // Required because it uses state (useState) and context import { QueryClient, QueryClientProvider } from '@tanstack/react-query'; import { WagmiProvider } from 'wagmi'; import { RainbowKitProvider } from '@rainbow-me/rainbowkit'; // Import necessary styles for RainbowKit components import '@rainbow-me/rainbowkit/styles.css'; import { useState } from 'react'; // Assume `config` is your Wagmi configuration object, imported from elsewhere import { config } from '@/wagmiConfig'; // Example import path export default function Providers({ children }: { children: React.ReactNode }) { // Initialize QueryClient only once using useState const [queryClient] = useState(() => new QueryClient()); return ( // Provide Wagmi context <WagmiProvider config={config}> {/* Provide React Query context */} <QueryClientProvider client={queryClient}> {/* Provide RainbowKit context, enabling wallet connection UI */} <RainbowKitProvider> {/* Render the actual page content passed down from layout.tsx */} {children} </RainbowKitProvider> </QueryClientProvider> </WagmiProvider> ); } ``` This hierarchical wrapping ensures that `WagmiProvider`, `QueryClientProvider`, and `RainbowKitProvider` establish their contexts before any page component renders. It's also the ideal place to import global styles required by provider libraries, like RainbowKit's CSS. **3. Example Page (`src/app/page.tsx`)** Because this page component is rendered *as* the `children` within the structure defined by `layout.tsx` and `providers.tsx`, it automatically exists within the context of all configured providers. Therefore, it can directly use components or hooks that rely on these contexts without any specific setup on the page itself. ```typescript // src/app/page.tsx import { ConnectButton } from "@rainbow-me/rainbowkit"; export default function Home() { return ( <main style={{ padding: '2rem' }}> <h1>Welcome to the App</h1> {/* The ConnectButton works out-of-the-box because RainbowKitProvider is wrapping this page */} <ConnectButton /> <p> This page can use wallet connection features without any local setup. </p> </main> ); } ``` The `<ConnectButton />` from RainbowKit works seamlessly here because `RainbowKitProvider` (along with its dependency `WagmiProvider`) has already been initialized higher up in the component tree within `providers.tsx`. ### Benefits of the Provider Pattern Implementing providers this way offers significant advantages: * **Centralized Configuration:** All setup for Wagmi, React Query, and RainbowKit happens in one place (`providers.tsx`), making configuration updates easier. * **Code Maintainability:** Avoids repetitive setup code on every page. Changes only need to be made in the central provider file. * **DRY (Don't Repeat Yourself):** Adheres to the fundamental programming principle of reducing repetition. * **Cleanliness:** Page components remain focused on their specific content and logic, uncluttered by provider setup boilerplate. By structuring your Next.js web3 application with a dedicated `providers.tsx` component utilized within the root `layout.tsx`, you establish a robust and maintainable foundation for managing global configurations and state, allowing seamless access to essential services like wallet connections across your entire application.

Providers

What you'll learn

Course Description

Who is this course for?

Potential Careers

Meet your instructors

Thanks for checking us out

What you'll learn

Course Description

Who is this course for?

Potential Careers

Meet your instructors