3

您如何取消订阅 Relay Modern 中的订阅？

我已经按照如何使用 GraphQL React + Relay的订阅教程进行操作，但是 Relay Modern 网站也没有提及您如何取消订阅。

任何帮助都是极好的。

更新 - - - - -

根据 Lee Byron（参见 GitHub 问题），您只需要dispose() 调用requestSubscription()

对示例进行以下修改后：

./src/subscriptions/NewVoteSubscription.js（添加return到requestSubscription）

export default () => {
    const subscriptionConfig = {
    subscription: newVoteSubscription,
    variables: {},
    updater: proxyStore => {
        const createVoteField = proxyStore.getRootField('Vote')
        const newVote = createVoteField.getLinkedRecord('node')
        const updatedLink = newVote.getLinkedRecord('link')
        const linkId = updatedLink.getValue('id')
        const newVotes = updatedLink.getLinkedRecord('_votesMeta')
        const newVoteCount = newVotes.getValue('count')

        const link = proxyStore.get(linkId)
        link.getLinkedRecord('votes').setValue(newVoteCount, 'count')
    },
    onError: error => console.log(`An error occured:`, error)
  }

  return requestSubscription(
      environment,
      subscriptionConfig
  )

./src/components/LinkList.js (在组件上设置订阅然后使用componentWillUnmount它dispose())

componentDidMount() {
    this.subscription = NewVoteSubscription()
}

componentWillUnmount() {
    this.subscription.dispose()
}

这是我得到的错误：

Uncaught TypeError: Cannot read property 'dispose' of undefined
    at RelayObservable.js:94
    at doCleanup (RelayObservable.js:453)
    at Object.unsubscribe (RelayObservable.js:474)
    at RelayObservable.js:330
    at doCleanup (RelayObservable.js:453)
    at Object.unsubscribe (RelayObservable.js:474)
    at doCleanup (RelayObservable.js:450)
    at Object.unsubscribe [as dispose] (RelayObservable.js:474)
    at LinkList.componentWillUnmount (LinkList.js:18)
    at callComponentWillUnmountWithTimerInDev (react-dom.development.js:11123)
    at HTMLUnknownElement.callCallback (react-dom.development.js:1309)
    at Object.invokeGuardedCallbackDev (react-dom.development.js:1348)
    at invokeGuardedCallback (react-dom.development.js:1205)
    at safelyCallComponentWillUnmount (react-dom.development.js:11131)
    at commitUnmount (react-dom.development.js:11421)
    at unmountHostComponents (react-dom.development.js:11362)
    at commitDeletion (react-dom.development.js:11392)
    at commitAllHostEffects (react-dom.development.js:12279)
    at HTMLUnknownElement.callCallback (react-dom.development.js:1309)
    at Object.invokeGuardedCallbackDev (react-dom.development.js:1348)
    at invokeGuardedCallback (react-dom.development.js:1205)
    at commitAllWork (react-dom.development.js:12384)
    at workLoop (react-dom.development.js:12695)
    at HTMLUnknownElement.callCallback (react-dom.development.js:1309)
    at Object.invokeGuardedCallbackDev (react-dom.development.js:1348)
    at invokeGuardedCallback (react-dom.development.js:1205)
    at performWork (react-dom.development.js:12808)
    at batchedUpdates (react-dom.development.js:13262)
    at performFiberBatchedUpdates (react-dom.development.js:1656)
    at stackBatchedUpdates (react-dom.development.js:1647)
    at batchedUpdates (react-dom.development.js:1661)
    at Object.batchedUpdatesWithControlledComponents [as batchedUpdates] (react-dom.development.js:1674)
    at dispatchEvent (react-dom.development.js:1884)
4

2 回答 2

4

并设置 RelayEnvironment

function setupSubscription(config, variables, cacheConfig, observer) {
  const query = config.text;

  const subscriptionClient = new SubscriptionClient(websocketURL, {
    reconnect: true
  });

  const client = subscriptionClient.request({ query, variables }).subscribe({
    next: result => {
      observer.onNext({ data: result.data });
    },
    complete: () => {
      observer.onCompleted();
    },
    error: error => {
      observer.onError(error);
    }
  });

  return {
    dispose: client.unsubscribe
  };
}
于 2017-10-12T16:31:12.560 回答
0

由于relay-modern@6您需要 return observable 否则它将由于此错误而崩溃：RelayObservable: Unhandled Error TypeError: source.subscribe is not a function

代替

return {
    dispose: client.unsubscribe
};

你需要回报

return Observable.create(() => {
  // return cleanup function
  return yourFunctionToCleanUp;
});

您可以从中导入 Observable 的位置relay-runtime。

喜欢：

import {
  Observable,
} from 'relay-runtime';

因此，当您this.subscription.dispose()在componentWillUnmount现实中调用时，它将调用 function yourFunctionToCleanUp()。

于 2019-11-14T08:04:52.620 回答