NestJS上下文在graphql订阅中未定义_Graphql_Nestjs

NestJS上下文在graphql订阅中未定义

graphql nestjs

NestJS上下文在graphql订阅中未定义,graphql,nestjs,Graphql,Nestjs,有人能帮我吗，为什么我的订阅中没有定义上下文 @Subscription(returns => CommentsDto, { filter: (payload, variables, context) => { console.log({ payload, variables, context }) // <------------ context context undefined const isSameCode = variabl

有人能帮我吗，为什么我的订阅中没有定义上下文

@Subscription(returns => CommentsDto, {
    filter: (payload, variables, context) => {
        console.log({ payload, variables, context })  // <------------ context context undefined
        const isSameCode = variables.code === payload.newComment.code
        const isAuthorized = context.req.headers.clientauthorization === payload.clientauthorization
        return isSameCode && isAuthorized
    },
})
newComment(
    @Context() context,  
    @Args(({ name: 'code', type: () => String })) code: string,
) {
    console.log(context) // <------------ undefined 
    return this.publisherService.asyncIterator('newComment')
}

感谢您的帮助，因为在订阅的情况下Req和Res是未定义的，所以当您尝试记录上下文时，它是未定义的

要使上下文可用，您需要更改用于返回上下文（可在连接变量中找到）的保护。总而言之：

=>http/query和http中使用的req、res
=>WebSocket/订阅中使用的连接

现在，要正确获取上下文，您必须严格执行以下步骤：

修改应用程序模块文件以使用GraphqlModuleImport

修改Extract User Guard和Auth Guard（或您正在使用的任何防护）返回查询/变异和订阅案例的数据

使用订阅中的上下文接收数据

在身份验证服务中添加jwtTokenPayload提取器函数

Opitonal：Typescript的助手函数和DTO

1-详情：

 GraphQLModule.forRootAsync({
      //import AuthModule for JWT headers at graphql subscriptions
      imports: [AuthModule],
      //inject Auth Service
      inject: [AuthService],
      useFactory: async (authService: AuthService) => ({
        debug: true,
        playground: true,
        installSubscriptionHandlers: true,
        // pass the original req and res object into the graphql context,
        // get context with decorator `@Context() { req, res, payload, connection }: GqlContext`
        // req, res used in http/query&mutations, connection used in webSockets/subscriptions
        context: ({ req, res, payload, connection }: GqlContext) => ({
          req,
          res,
          payload,
          connection,
        }),
        // subscriptions/webSockets authentication
        typePaths: ["./**/*.graphql"],
        resolvers: { ...resolvers },
        subscriptions: {
          // get headers
          onConnect: (connectionParams: ConnectionParams) => {
            // convert header keys to lowercase
            const connectionParamsLowerKeys: Object = mapKeysToLowerCase(
              connectionParams,
            );
            // get authToken from authorization header
            let authToken: string | false = false;

            const val = connectionParamsLowerKeys["authorization"];

            if (val != null && typeof val === "string") {
              authToken = val.split(" ")[1];
            }

            if (authToken) {
              // verify authToken/getJwtPayLoad
              const jwtPayload: JwtPayload = authService.getJwtPayLoad(
                authToken,
              );

              // the user/jwtPayload object found will be available as context.currentUser/jwtPayload in your GraphQL resolvers
              return {
                currentUser: jwtPayload.username,
                jwtPayload,
                headers: connectionParamsLowerKeys,
              };
            }
            throw new AuthenticationError("authToken must be provided");
          },
        },
        definitions: {
          path: join(process.cwd(), "src/graphql.classes.ts"),
          outputAs: "class",
        },
      }),
    }),

2-详细信息：我的getRequest函数示例来自扩展AuthGuard（jwt）类的ExtractUserGuard类

更改为：

  getRequest(context: ExecutionContext) {
    const ctx = GqlExecutionContext.create(context);
    const request = ctx.getContext().req;
    return request;}

为此：


 getRequest(context: ExecutionContext) {
    const ctx = GqlExecutionContext.create(context);
// req used in http queries and mutations, connection is used in websocket subscription connections, check AppModule
    const { req, connection } = ctx.getContext();
    // if subscriptions/webSockets, let it pass headers from connection.context to passport-jwt
    const requestData =
      connection && connection.context && connection.context.headers
        ? connection.context
        : req;
    return requestData;
}

3-现在您可以在解析器中获取此数据

  @Subscription("testSubscription")
  @UseGuards(ExtractUserGuard)
  async testSubscription(
    @Context("connection") connection: any,
  ): Promise<JSONObject> {
    const subTopic = `${Subscriptions_Test_Event}.${connection.context.jwtPayload.email}`;
    console.log("Listening to the event:", subTopic);

    return this.pubSub.asyncIterator(subTopic);
  }

5-Helper函数和DTO示例（我在项目中使用的）

DTO：

辅助功能：

export function mapKeysToLowerCase(
  inputObject: Record<string, any>,
): Record<string, any> {
  let key;
  const keys = Object.keys(inputObject);
  let n = keys.length;
  const newobj: Record<string, any> = {};
  while (n--) {
    key = keys[n];
    newobj[key.toLowerCase()] = inputObject[key];
  }
  return newobj;
}

导出函数MapKeyStore小写(
输入对象：记录，
)：记录{
让钥匙；
常量键=Object.keys（inputObject）；
设n=keys.length；
const newobj:Record={}；
而（n--）{
键=键[n]；
newobj[key.toLowerCase（）]=inputObject[key]；
}
返回newobj；
}

因为在订阅的情况下，Req和Res是未定义的，所以当您尝试记录上下文时，它是未定义的