Question

我认为我正确设置了后端订阅。我在客户端使用angular，当我尝试调用subscribe时出现错误

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); },
  }
);

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

也许我在后端错过了一些东西？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中的架构

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，你缺少设置功能。您可以查看此链接graphql subscription docu或example。

您的订阅管理器可能如下所示：

＆＃13;

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
        },
      },
    }),
  },
});

＆＃13;

当您调用pubsub发布函数时，您必须像pubsub.publish("passwordUpdatedChannel")一样编写它。

Sidenode：您可能希望将已更改密码的用户的ID添加到订阅中。如果您这样做，可以将其添加到过滤器选项，可能看起来像filter: (user) => {return user.id === args.userId}

GraphQL订阅：调用apolloClient.subscribe

1 个答案: