Next

Kind: Constant

Source: packages/common/decorators/http/route-params.decorator.ts

Part of: Common

Route handler parameter decorator. Extracts reference to the Next function from the underlying platform and populates the decorated parameter with the value of Next.

Next is a route handler parameter decorator that injects the underlying platform’s next callback into a controller method parameter. It is primarily used in Express-based applications to delegate control to the next middleware or error handler in the request pipeline.

Definition

ts
() => ParameterDecorator

Value

ts
createRouteParamDecorator(
  RouteParamtypes.NEXT,
)

Diagram

mermaid
graph LR
  A[Incoming HTTP Request] --> B[Middleware Pipeline]
  B --> C[Controller Route Handler]
  C --> D[@Next() Decorated Parameter]
  D --> E[next Function]
  E --> F[Next Middleware or Error Handler]

Usage

ts
import { Controller, Get, Next } from '@nestjs/common';
import type { NextFunction } from 'express';

@Controller('users')
export class UsersController {
  @Get()
  findAll(@Next() next: NextFunction) {
    try {
      // Handle the request or delegate to later middleware.
      next();
    } catch (error) {
      next(error);
    }
  }
}

AI Coding Instructions

• Use @Next() only on route-handler parameters where direct access to the platform middleware flow is required.
• Type the injected value as NextFunction when using the Express platform.
• Call next(error) to delegate unexpected errors to registered error-handling middleware.
• Prefer NestJS guards, interceptors, pipes, and exception filters for framework-native request handling when possible.
• Ensure the selected HTTP adapter supports a next callback before relying on this decorator.