GraphQL订阅:调用apolloClient.subscribe的错误

问题描述:

我想我的后端订阅设置正确。我使用的角度在客户端上,当我尝试打电话subscribe我得到一个错误GraphQL订阅:调用apolloClient.subscribe的错误

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); }, 
    } 
); 

然后这是错误控制台出现 {"type":"subscription_fail","id":0,"payload":{"errors":[{"message":"Cannot read property 'subscribe' of undefined"}]}}

在后端也许我失去了一些东西?我是否需要在SubscriptionManager中定义setupFunctions

这是我SubscriptionManager

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

这是我在graphQL

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 
    } 
`); 
+0

错误是告诉你,在这种情况下apollo客户端是未定义的。你已经检查过吗? –

+0

@ Locco0_0,我已检查过。它不是没有定义的。其他操作如'watchQuery'和'mutation'正在工作,虽然 –

+0

好,所以请在服务器上显示Subscription Manager。你使用哪个节点包?我想你错过了设置功能。你使用什么样的发布订阅? –

模式是你缺少的设置功能。你可以看看这个链接graphql subscription docuexample

你的订阅管理器看起来是这样的:

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

当你调用PubSub的发布,你必须把它写这样pubsub.publish("passwordUpdatedChannel")功能。

Sidenode:您可能想要将密码已更改为用户的用户的ID添加到订阅中。如果你这样做,你可以将它添加到过滤器选项,可能看起来像这样filter: (user) => {return user.id === args.userId}

+0

谢谢!它解决了问题! –