Use Inject outside class

[lgmf]

import {UseAfter} from "@tsed/platform-middlewares";
import {useDecorators} from "@tsed/core";

export function CustomStatus(code: number) {
  return useDecorators(
    UseAfter((req: any, res: any, next: any) => {
      res.status(code);
      next();
    })
  );
}

I've seen this example on the docs.

How can I use the DI in this case?

[Romakita]

Why?

[Romakita]

Optimization:

@Middleware()
class MyMiddlewareImpl implements MiddlewareMethods {
  static params: MyMiddlewareParams;

  async use(@Context() ctx: Context) {
    const code = ctx.endpoint.store.get("code") || ctx.endpoint.parent.store.get("code");

    ctx.set("code", code);
  }
}

Use Next decorator is not necessary in most case because Ts.ED handle async method/Observable/Stream. Next is just here to wrap an Express middleware. But even then, it's not necessary.

[lgmf]

No problem at all!

Got it.

Thanks a lot for the help :D

[Romakita]

You can mark this topic as answered ;)

[lgmf]

Done!

If you wanna paste the answer in a different comment to make it easier to find I can mark it later as the answer

[Romakita]

@lgmf done ;)

[Romakita]

Use a middleware on class and/or endpoint and store data

This example show you, how you can create a custom decorator to collect metadata on class and/or on class method and register a middleware.

import {Context, Middleware, MiddlewareMethods, UseBeforeEach} from "@tsed/common";
import {StoreSet, useDecorators} from "@tsed/core";

interface MyMiddlewareParams {
  code: number;
}

@Middleware()
class MyMiddlewareImpl implements MiddlewareMethods {
  static params: MyMiddlewareParams;

  async use(@Context() ctx: Context) {
    const code = ctx.endpoint.store.get("code") || ctx.endpoint.parent.store.get("code");

    ctx.set("code", code);
  }
}

export function MyMiddleware(code: number) {
  return useDecorators(StoreSet("code", code), UseBeforeEach(MyMiddlewareImpl));
}

The trick is around this code: const code = ctx.endpoint.store.get("code") || ctx.endpoint.parent.store.get("code");

SetStore is always contextualized. So if you use SetStore on top of the class. The metadata is stored on target. But if you use it on endpoint, the metadata is automatically attached to the EndpointMetadata.store.

Usage on controller

import {Controller} from "@tsed/di";
import {Get} from "@tsed/schema";
import {Context} from "@tsed/common";

import {MyMiddleware} from "../../middlewares/MyMiddleware";

@Controller("/test")
@MyMiddleware(999) // by default
export class HelloWorldController {

  @Get("/scenario-1")
  @MyMiddleware(777) // specific to the current endpoint
  work(@Context("code") code: number) {
    return {code}; // 777
  }

  @Get("/scenario-2")
  doesntWork(@Context("code") code: number) {
    return {code};  // 999 - value set on controller
  }
}

See you
Romain

[lgmf]

It worked!

Thanks