oak decorators

Project implements decorators like implementation of Nest.js for Deno’s web framework oak.

Usage

The following are the core files that need to be created in the first step.

// ./main.ts
import { Application } from "https://deno.land/x/oak/mod.ts";
import { assignModule } from "https://deno.land/x/oak_decorators/mod.ts";
import { AppModule } from "./app.module.ts";

const app = new Application();
app.use(assignModule(AppModule));

await app.listen({ port: 8000 });

// ./app.module.ts
import { Module } from "https://deno.land/x/oak_decorators/mod.ts";
import { AppController } from "./app.controller.ts";

@Module({
  controllers: [AppController],
  routePrefix: "v1",
})
export class AppModule {}

// ./app.controller.ts
import { Controller, Get, Headers } from "https://deno.land/x/oak_decorators/mod.ts";

@Controller()
export class AppController {
  @Get()
  get(@Headers("user-agent") userAgent: string) {
    return { status: "ok", userAgent };
  }
}

Here’s a brief overview of those core files:

name	description
`app.module.ts`	The root module of the application.
`app.controller.ts`	A basic controller with a single route.
`main.ts`	The entry file of the application which uses the core middleware assignModule to use decorations.

Docs

Modules

A module is a class annotated with a @Module() decorator. The @Module() decorator provides metadata that the application makes use of to organize the application structure.
Each application has at least one module, a root module, and each modules can have child modules.

The @Module() decorator takes those options:

name	description
`controllers`	the set of controllers defined in this module which have to be instantiated
`providers`	the providers that will be instantiated by the injector
`modules`	the set of modules defined as child modules of this module
`routePrefix`	the prefix name to be set in route as the common ULR for controllers.

import { Module } from "https://deno.land/x/oak_decorators/mod.ts";
import { AppController } from "./app.controller.ts";
import { SampleModule } from "./sample/sample.module.ts";

@Module({
  modules: [SampleModule],
  controllers: [AppController],
  routePrefix: "v1",
})
export class AppModule {}

Controllers

Routing

A controller is a class annotated with a @Controller() decorator. Controllers are responsible for handling incoming requests and returning responses to the client. The @Controller() decorator take a route path prefix optionally.

import { Controller, Get } from "https://deno.land/x/oak_decorators/mod.ts";

@Controller('sample')
export class SampleController {
  @Get()
  findAll(): string {
    return 'OK';
  }
}

The @Get() HTTP request method decorator before the findAll() method tells the application to create a handler for a specific endpoint for HTTP requests.

For http methods, you can use @Get(), @Post(), @Put(), @Patch(), @Delete().

Request object

Handlers often need access to the client request details.
HHere’s a example to access the request object using @Req() decorator.

import { Controller, Get, Req } from "https://deno.land/x/oak_decorators/mod.ts";

@Controller('sample')
export class SampleController {
  @Get()
  findAll(@Req() request: Request): string {
    return 'OK';
  }
}

Below is a list of the provided decorators.

name
`@Request()`
`@Response()`
`@Next()`
`@Query(key?: string)`
`@Param(key?: string)`
`@Body(key?: string)`
`@Headers(name?: string)`
`@Ip()`

Providers

Providers are responsible for main business logic as services, repositories, factories, helpers, and so on.
The main idea of a provider is that it can be injected as dependency.

// ./sample.service.ts
import { Injectable } from "https://deno.land/x/oak_decorators/mod.ts";

@Injectable()
export class SampleService {
  get() {
    return { status: "ok" };
  }
}

// ./sample.controller.ts
import { Controller, Get } from "https://deno.land/x/oak_decorators/mod.ts";
import { SampleService } from "./sample.service.ts";

@Controller('sample')
export class SampleController {
  constructor(private readonly sampleService: SampleService) {}

  @Get()
  get() {
    return this.sampleService.get();
  }
}

// ./sample.module.ts
import { Module } from "https://deno.land/x/oak_decorators/mod.ts";
import { SampleController } from "./sample.controller.ts";
import { SampleService } from "./sample.service.ts";

@Module({
  controllers: [SampleController],
  providers: [SampleService],
})
export class SampleModule {}