OOP & Decorators Architecture

Velociradix provides a dedicated Decorators & Dependency Injection module (velociradix/decorators), allowing you to write clean, class-based controllers (similar to NestJS or Spring Boot) while maintaining maximum C++ native routing performance.

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1. Quick Example

import { createApp } from "velociradix";
import {
  Controller,
  Get,
  Post,
  Body,
  Param,
  Query,
  Use,
  Injectable,
  Inject,
} from "velociradix/decorators";

// 1. Define an Injectable Service
@Injectable()
class UserService {
  private users = [
    { id: 1, name: "Alice", role: "admin" },
    { id: 2, name: "Bob", role: "user" },
  ];

  findAll() {
    return this.users;
  }
  findOne(id: number) {
    return this.users.find((u) => u.id === id);
  }
  create(data: { id: number; name: string; role: string }) {
    this.users.push(data);
    return data;
  }
}

// 2. Define a Decorated Controller
@Controller("/users")
class UserController {
  @Inject(UserService)
  private userService: UserService;

  @Get("/")
  getAllUsers(@Query("role") role: string) {
    const all = this.userService.findAll();
    return role ? all.filter((u) => u.role === role) : all;
  }

  @Get("/:id")
  getUserById(@Param("id") id: string) {
    const user = this.userService.findOne(Number(id));
    return user || { error: "Not found" };
  }

  @Post("/")
  createUser(@Body() body: { id: number; name: string; role: string }) {
    return this.userService.create(body);
  }
}

// 3. Register Controller onto App
const app = createApp();
app.registerController(UserController);

app.listen(3000);

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2. Available Decorators

Class Decorators

• @Controller(prefix?, options?): Marks class as a route group with an optional URL prefix.
• @Injectable(): Marks a class as a registered injectable dependency in the IoC container.

Method Decorators (Route Verbs)

• @Get(path?)
• @Post(path?)
• @Put(path?)
• @Delete(path?)
• @Patch(path?)
• @Head(path?)
• @Options(path?)
• @All(path?)

Parameter Decorators

• @Body(property?): Injects request body or specific field.
• @Param(name?): Injects route parameter (e.g. :id).
• @Query(name?): Injects query string parameter.
• @Headers(name?): Injects HTTP request header.
• @Ctx(): Injects the full Velociradix Context object.
• @State(property?): Injects ctx.state.

Middleware Decorators

• @Use(...middlewares): Applies middlewares to an entire controller class or specific action method.
• @Validate(schema): Applies automatic schema validation to an action method.

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3. TypeScript Setup

Ensure your tsconfig.json enables experimental decorators:

{
  "compilerOptions": {
    "experimentalDecorators": true,
    "emitDecoratorMetadata": true
  }
}