Question

我正在我的Loopback 4应用上设置Bearer Token身份验证，并且遵循以下常规实现：https://github.com/strongloop/loopback-next/tree/master/packages/authentication。

在我的src/providers/auth-strategy.provider.ts中，我需要对存储库对象的引用才能查询我的数据源。我希望通过在正在使用的类的构造函数中使用@repository装饰器进行依赖项注入来实现此目标。

但是，当我在由findOne()装饰器创建的存储库引用中调用@repository时，会产生以下错误：

TypeError: Cannot read property 'findOne' of undefined

这是我的auth-strategy.provider.ts版本：

import {Provider, inject, ValueOrPromise} from '@loopback/context';
import {Strategy} from 'passport';
import {
  AuthenticationBindings,
  AuthenticationMetadata,
} from '@loopback/authentication';
import {IVerifyOptions} from 'passport-http-bearer';
import {ApiClient} from '../models';
import {ApiClientRepository} from '../repositories';
import {Strategy as BearerStrategy} from 'passport-http-bearer';
import {repository} from '@loopback/repository';

export class BearerStrategyProvider implements Provider<Strategy | undefined> {
  constructor(
    @inject(AuthenticationBindings.METADATA)
    private metadata: AuthenticationMetadata,
    @repository(ApiClientRepository)
    private apiClientRepository: ApiClientRepository,
  ) {}

  value(): ValueOrPromise<Strategy | undefined> {
    // The function was not decorated, so we shouldn't attempt authentication
    if (!this.metadata) {
      return undefined;
    }

    const name = this.metadata.strategy;
    if (name === 'BearerStrategy') {
      return new BearerStrategy(this.verify);
    } else {
      return Promise.reject(`The strategy ${name} is not available.`);
    }
  }

  async verify(
    token: string,
    done: (error: any, user?: any, options?: IVerifyOptions | string) => void,
  ) {
    // call cb(null, false) when user not found
    // call cb(null, user) when user is authenticated
    let apiClient: ApiClient | null;
    try {
      apiClient = await this.apiClientRepository.findOne({
        where: {Token: token},
      });
      if (apiClient) {
        console.log("Found CLIENT!!! Here: " + apiClient.Email);
        done(null, {user: apiClient});
      } else {
        // if token not found in DB:
        done('Authentication Error.', false);
      }
    } catch (e) {
      console.log(e);
    }
  }
}

Answer 1

实际上，我认为在您的情况下，问题与此相同： https://github.com/strongloop/loopback-next/issues/1835

您应该将您的verify函数的上下文绑定到您的类，否则this不是BearerStrategyProvider而是BearerStrategy，则this.apiClientRepository在该类中不存在。您可以这样绑定它：

return new BearerStrategy(this.verify.bind(this));

环回4：@repository依赖项注入失败（TypeError：无法读取未定义的属性'findOne'）

1 个答案: