@aaronpowell/graphql-cosmosdb-subscriptions 中文文档教程
CosmosDB GraphQL Subscriptions 
此软件包包含对 Apollo GraphQL 订阅 的支持，使用 Azure CosmosDB 更改源。
Installation
通过 npm 或 GitHub Packages 安装：
$> npm install --save @aaronpowell/graphql-cosmosdb-subscriptions
Usage
您需要一个 SignalR 服务帐户（如果您没有 Azure 帐户 免费注册)。 复制连接字符串并在您创建 SignalRPubSub 实例时提供它：
import { CosmosDBPubSub } from "@aaronpowell/graphql-cosmosdb-subscriptions";
const cosmosPubSub = new CosmosDBPubSub(
new CosmosClient(process.env.COSMOS_CONNECTION_STRING || "")
.database(process.env.COSMOS_DB || "")
.container(process.env.COSMOS_CONTAINER || "")
);
与大多数 pubsub 库不同，您不需要直接发布，当 Change Feed 收到消息时就会收到消息。 创建订阅时，您订阅了一个 CosmosDB 分区键值（在下面的示例中，type 是分区键，我们在 type = 'message' 时订阅）。
export const resolvers = {
Query: {
async hello(parent, args, { dataSources }) {
const text = `Message! ${Date.now()}`;
await dataSources.messages.createOne({
id: Date.now() + "",
text,
type: "message",
});
return text;
},
},
Subscription: {
getMessage: {
subscribe: () => cosmosPubSub.asyncIterator(["message"]),
},
},
};
CosmosDB GraphQL Subscriptions
This package contains support for Apollo GraphQL Subscriptions, using the Azure CosmosDB Change Feed.
Installation
Install via npm or GitHub Packages:
$> npm install --save @aaronpowell/graphql-cosmosdb-subscriptions
Usage
You'll need a SignalR Service account (if you don't have an Azure account sign up for free). Copy the connection string and provide it when you create an instance of SignalRPubSub:
import { CosmosDBPubSub } from "@aaronpowell/graphql-cosmosdb-subscriptions";
const cosmosPubSub = new CosmosDBPubSub(
new CosmosClient(process.env.COSMOS_CONNECTION_STRING || "")
.database(process.env.COSMOS_DB || "")
.container(process.env.COSMOS_CONTAINER || "")
);
Unlike most pubsub libraries, you don't need to publish directly, messages are received when the Change Feed receives messages. When creating the subscription, you subscribe to a CosmosDB partition key value (in the below example type is the partition key and we're subscription when type = 'message').
export const resolvers = {
Query: {
async hello(parent, args, { dataSources }) {
const text = `Message! ${Date.now()}`;
await dataSources.messages.createOne({
id: Date.now() + "",
text,
type: "message",
});
return text;
},
},
Subscription: {
getMessage: {
subscribe: () => cosmosPubSub.asyncIterator(["message"]),
},
},
};
