Guide to making a personalized decorator in loopback4

Question

Guide to making a personalized decorator in loopback4

  async verifyUserMembership(userId: string, productId: string) {
    if (userId && productId) {
       const userExists = await Product.find({ where: { userId: userId, id: productId } });
       return !!userExists;
    }
    return false;
  }

I am interested in turning this function into a decorator and applying it to the above endpoint. Here is an example:

  @verifyUserMembership()

  @post('/roles')
  async create(
    @requestBody() newUser: User
  ): Promise<Role> {
    return this.roleRepository.create(role);
  }

I'm unsure how to pass the request body to this decorator. Can this function be used as a decorator?

typescript loopbackjs strongloop loopback4

Answer 1

Answer №1

I believe using an interceptor could be a potential solution. Below is a sample code snippet that demonstrates how to use an interceptor:

import {inject, intercept, Interceptor} from '@loopback/context';
import {get, HttpErrors, RestBindings} from '@loopback/rest';

const myInterceptor: Interceptor = async (invocationCtx, next) => {
  // Your custom logic goes here
  
  // If operation is successful
  next();

  // If there is an error
  throw new HttpErrors.NotFound();
};

export class PingController {
  constructor() {}

  @intercept(myInterceptor)
  @post('/test')
  async test(@requestBody() body: any) {
    // Write your implementation logic here
  }
}

Answer 2

I believe using an interceptor could be a potential solution. Below is a sample code snippet that demonstrates how to use an interceptor:

import {inject, intercept, Interceptor} from '@loopback/context';
import {get, HttpErrors, RestBindings} from '@loopback/rest';

const myInterceptor: Interceptor = async (invocationCtx, next) => {
  // Your custom logic goes here
  
  // If operation is successful
  next();

  // If there is an error
  throw new HttpErrors.NotFound();
};

export class PingController {
  constructor() {}

  @intercept(myInterceptor)
  @post('/test')
  async test(@requestBody() body: any) {
    // Write your implementation logic here
  }
}

Guide to making a personalized decorator in loopback4

Answer №1

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