GraphQL订阅:调用apolloClient.subscribe时出错

Question

我想我的后端订阅设置是正确的。我在客户端使用了角，当我试图调用subscribe时，我得到了一个错误

passwordUpdatedSubscription = gql`
subscription passwordUpdated{passwordUpdated{name password}}
`;

// Apollo Subscription
var subscription = this.apollo.subscribe({
  query: this.passwordUpdatedSubscription
});

subscription.subscribe(
  {
    next(data) {
      console.log(data);
    },
    error(err) { console.error('err', err); },
  }
);

这就是控制台{"type":"subscription_fail","id":0,"payload":{"errors":[{"message":"Cannot read property 'subscribe' of undefined"}]}}中出现的错误

也许我在后端漏掉了什么？我是否需要在setupFunctions中定义SubscriptionManager

这是我的SubscriptionManager

const sub = require('graphql-subscriptions');
const pubSub = new sub.PubSub();
const manager = new sub.SubscriptionManager({
    schema,
    pubSub
});

这是我在graphQL中的模式

const graphql = require('graphql');

var schema = graphql.buildSchema(`
    type Subscription {
      passwordUpdated: User
    }
    type Mutation {
      setMessage(message: String): String,
      updateUserPassword(userName: String, password: String): User!
    }

    type Query {
      getMessage: String,
      getUsers: [User],
      findUsers(userName: String): [User]
    }

    type User {
        name: String,
        password: String
    }
`);

Answer 1

是的，您缺少安装功能。您可以看看这个链接graphql订阅docu或示例。

订阅管理器可能如下所示：

​

const manager = new sub.SubscriptionManager({
  schema,
  pubSub,

  setupFunctions: {
    passwordUpdated: (options, args) => ({ // name of your graphQL subscription
      passwordUpdatedChannel: { // name of your pubsub publish-tag
        filter: () => {
          return true
        },
      },
    }),
  },
});

​

当您调用pubsub发布函数时，您必须像这样编写它：pubsub.publish("passwordUpdatedChannel")。

Sidenode:您可能希望添加已将密码更改为订阅的用户的id。如果您这样做，您可以将它添加到filter选项中，可能类似于下面的filter: (user) => {return user.id === args.userId}