我的组件正在调用订阅查询,但由于某种原因,未访问订阅解析程序:其中的断点永远不会被激活。然而在客户端,我得到了GraphQL订阅错误:
“订阅必须返回Async Iterable。收到:未定义”
导致这种情况的原因是什么?
提前致谢所有信息。
订阅查询
const IM_SUBSCRIPTION_QUERY = gql`
subscription getIMsViaSubscription($fromID: String!, $toID: String!){
IMAdded(fromID:$fromID, toID: $toID){
id,
fromID,
toID,
msgText,
myUserData{
id,
name_first,
name_last,
picture_large,
picture_medium,
picture_thumbnail
my_category
}
}
}
`;
RESOLVER
Subscription: {
IMAdded(IMThatWasAdded) {
debugger; <== IS NEVER ACTIVATED
subscribe: withFilter(() => SubscriptionServer.pubsub.asyncIterator(IM_ADDED_CHANNEL), (newIM, args) => {
const callIsFromMsgFoldersComponent = args.toID == 0;
var result;
if (callIsFromMsgFoldersComponent){
result = (newIM.fromID === args.fromID || newIM.toID === args.fromID);
} else {
result = ((newIM.fromID === args.fromID && newIM.toID === args.toID) || (newIM.fromID === args.toID && newIM.toID === args.fromID));
}
return result;
})
COMPONENT
const withDataAndSubscription = graphql(GETIMS_QUERY, {
options({toID}) {
console.log(GETIMS_QUERY);
const fromID = Meteor.userId();
return {
fetchPolicy: 'cache-and-network',
variables: {fromID: `${fromID}`, toID: `${toID}`}
};
}
,
props: props => {
debugger;
return {
loading: props.data.loading,
instant_message: props.data.instant_message,
subscribeToMore: props.data.subscribeToMore,
subscribeToNewIMs: params => {
debugger; <==IS ACTIVATED AS EXPECTED
console.log(IM_SUBSCRIPTION_QUERY); <==IS OKAY
const fromID = Meteor.userId();
const toID = params.toID;
return props.data.subscribeToMore({
document: IM_SUBSCRIPTION_QUERY,
variables: {fromID: `${fromID}`, toID: `${toID}`},
updateQuery: (previousResult, {subscriptionData}) => {
if (!subscriptionData.data) {
return previousResult;
}
const newMsg = subscriptionData.data.createIM;
return update(previousResult, {
instant_message: {
$push: [newMsg],
},
});
}
});
}
};
},
})
;
答案 0 :(得分:0)
服务器端设置和变异/订阅解析器自我的帖子中的代码发生了很大变化,该帖子基于去年年底的Apollo库。以下代码适用于当前的Apollo库,通过this tutorial:
服务器设置
import express from 'express';
import { graphqlExpress, graphiqlExpress } from 'graphql-server-express';
import bodyParser from 'body-parser';
import cors from 'cors';
import { execute, subscribe } from 'graphql';
import { createServer } from 'http';
import { SubscriptionServer } from 'subscriptions-transport-ws';
import schema from '/imports/api/schema';
//SET UP APOLLO QUERY / MUTATIONS / PUBSUB
const METEOR_PORT = 3000;
const GRAPHQL_PORT = 4000;
const server = express();
server.use('*', cors({ origin: 'http://localhost:${METEOR_PORT}' }));
server.use('/graphql', bodyParser.json(), graphqlExpress({
schema
}));
server.use('/graphiql', graphiqlExpress({
endpointURL: '/graphql',
subscriptionsEndpoint: `ws://localhost:${GRAPHQL_PORT}/subscriptions`
}));
// Wrap the Express server
const ws = createServer(server);
ws.listen(GRAPHQL_PORT, () => {
console.log(`GraphQL Server is now running on http://localhost:${GRAPHQL_PORT}`);
// Set up the WebSocket for handling GraphQL subscriptions
new SubscriptionServer({
execute,
subscribe,
schema
}, {
server: ws,
path: '/subscriptions',
});
});
//END OF SET UP APOLLO PUBSUB
MUTATION RESOLVER
Mutation: {
createIM(root, args, context) {
var associatedUsers = [];
associatedUsers.push(args.fromID);
associatedUsers.push(args.toID);
var IDofNewIM;
return Promise.resolve()
.then(() => {
const newIM = connectors.IMs.create(args);
return newIM;
})
.then(IMAdded => {
// publish subscription notification
pubsub.publish(IM_ADDED_CHANNEL, { IMAdded, args});
return IMAdded;
})
.catch((err)=> {
console.log(err);
});
},
SUBSCRIPTION RESOLVER
IMAdded: {
subscribe: withFilter(
() => pubsub.asyncIterator(IM_ADDED_CHANNEL),
(IMAdded, args) => {
IMAdded = IMAdded.IMAdded;
var result = ((IMAdded.fromID === args.fromID && IMAdded.toID === args.toID) || (IMAdded.fromID === args.toID && IMAdded.toID === args.fromID));
return result;
}
)
},