Overview
Chain processing objects to handle requests
Middleware Pattern
4 implementations available
When to Use
- When you need to abstract data access logic
- When you want to make your code testable
- When you need to support multiple data sources
- When you want to decouple business logic from infrastructure
Available Implementations
Logger Middleware
HTTP request logging with timing and sensitive data masking
npx hanma add elysia-logger --framework elysia
Request/response timingSensitive data maskingConfigurable exclusion paths
Security Headers
Security headers middleware with CSP, HSTS, and more
npx hanma add elysia-security-headers --framework elysia
Content-Security-PolicyStrict-Transport-SecurityX-Frame-Options
Compression
Response compression using Bun's native gzip
npx hanma add elysia-compression --framework elysia
Bun native gzipConfigurable thresholdContent-type filtering
Zod Integration
Zod schema integration with validation middleware
npx hanma add elysia-zod --framework elysia
Zod integrationError formattingValidation middleware
Basic Example
// Middleware Pattern implementation example
// This shows the basic structure of middleware pattern in Elysia
// Define your interface
interface IRepository {
findAll(): Promise<T[]>;
findById(id: string): Promise<T | null>;
create(data: CreateDto): Promise<T>;
update(id: string, data: UpdateDto): Promise<T>;
delete(id: string): Promise<void>;
}
// Implement the pattern
class MiddlewareRepository implements IRepository {
async findAll(): Promise<T[]> {
// Implementation
}
async findById(id: string): Promise<T | null> {
// Implementation
}
async create(data: CreateDto): Promise<T> {
// Implementation
}
async update(id: string, data: UpdateDto): Promise<T> {
// Implementation
}
async delete(id: string): Promise<void> {
// Implementation
}
}
// Use the pattern
const repository = new MiddlewareRepository();
const items = await repository.findAll();
Frequently Asked Questions
What is Middleware Pattern?
Chain processing objects to handle requests. It's a well-established software design pattern that helps organize code for better maintainability and testability.
How does Middleware Pattern work with Elysia?
Elysia provides excellent support for this pattern through its dependency injection system and middleware composition.
What are the benefits?
Improved testability, separation of concerns, easier maintenance, and flexibility to change implementations without affecting business logic.
When should I avoid this pattern?
For very simple applications with minimal logic, the pattern may add unnecessary complexity. Use judgment based on project requirements.