您如何映射Apollo中GraphQl订阅的PubSub值？

发布于 2025-02-07 17:01:11 字数 1408 浏览 1 评论 0原文

我正在阿波罗制作GraphQL后端，我想使用订阅。我遵循了阿波罗的文档，并且使用graphql-subscriptions获得了基本订阅。此软件包还通过fifilter 函数进行过滤。但是，我不想发出通过pubsub发布的所有数据，因为其中一些数据仅用于过滤目的。

前任。

// GraphQL Schema
type Subscription {
  mySubscription(filter: MySubscriptionFilter!): ID!
}

// Publishing the event
pubsub.publish("MY_SUBSCRIPTION", { id: "2092330", username: "asdf", roles: [ "USER", "MODERATOR" ] });

// Handling the event for a subscription
const resolvers = {
  Subscriptions: {
    mySubscription: {
      subscribe: withFilter(
        () => pubsub.asyncIterator("MY_SUBSCRIPTION"),
        (payload, variables) => {
          return customFiltering(payload, variables);
        }
      )
    }
  }
}

这将返回具有类型的对象：{id，用户名，角色}。但是，用户名和角色字段仅用于过滤。我最终需要返回一个类型{mySubScription：id}的对象，因为这就是我的GraphQl Schema所说的。

有办法做这样的事情吗？

// Handling the event for a subscription
const resolvers = {
  Subscriptions: {
    mySubscription: {
      subscribe: withFilter(
        () => pubsub.asyncIterator("MY_SUBSCRIPTION"),
        (payload, variables) => {
          return customFiltering(payload, variables);
        }
      ).map(x => {
        return { mySubsription: x.id }
      }) // Map function where x is the payload from the pubsub
    }
  }
}

原文

I'm making a GraphQL backend in Apollo, and I'd like to use subscriptions. I followed Apollo's docs, and I've gotten basic subscriptions working using graphql-subscriptions. This package also comes with filtering via the built-in withFilter function. However, I don't want to emit all of the data published via PubSub because some of this data is used for filtering purposes only.

Ex.

// GraphQL Schema
type Subscription {
  mySubscription(filter: MySubscriptionFilter!): ID!
}

// Publishing the event
pubsub.publish("MY_SUBSCRIPTION", { id: "2092330", username: "asdf", roles: [ "USER", "MODERATOR" ] });

// Handling the event for a subscription
const resolvers = {
  Subscriptions: {
    mySubscription: {
      subscribe: withFilter(
        () => pubsub.asyncIterator("MY_SUBSCRIPTION"),
        (payload, variables) => {
          return customFiltering(payload, variables);
        }
      )
    }
  }
}

This returns an object with the type: { id, username, roles }. However, the username and roles fields are only used for filtering. I ultimately need to return an object of type { mySubscription: id }, because that's what my GraphQL schema says.

Is there a way to do something like this?

// Handling the event for a subscription
const resolvers = {
  Subscriptions: {
    mySubscription: {
      subscribe: withFilter(
        () => pubsub.asyncIterator("MY_SUBSCRIPTION"),
        (payload, variables) => {
          return customFiltering(payload, variables);
        }
      ).map(x => {
        return { mySubsription: x.id }
      }) // Map function where x is the payload from the pubsub
    }
  }
}

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相对绾红妆 2025-02-14 17:01:12

哎呀，看来我忽略了订阅中的解决函数。

来自graphql-subscriptions

”

您也可以通过在订阅中添加解决方法来操纵已发布的有效载荷：

const SOMETHING_UPDATED = 'something_updated';

export const resolvers = {
  Subscription: {
    somethingChanged: {
      resolve: (payload, args, context, info) => {
        // Manipulate and return the new value
        return payload.somethingChanged;
      },
      subscribe: () => pubsub.asyncIterator(SOMETHING_UPDATED),
    },
  },
}

Whoops, it looks like I overlooked the resolve function in a subscription.

From the graphql-subscriptions github page

Payload Manipulation

You can also manipulate the published payload, by adding resolve methods to your subscription:

const SOMETHING_UPDATED = 'something_updated';

export const resolvers = {
  Subscription: {
    somethingChanged: {
      resolve: (payload, args, context, info) => {
        // Manipulate and return the new value
        return payload.somethingChanged;
      },
      subscribe: () => pubsub.asyncIterator(SOMETHING_UPDATED),
    },
  },
}

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