以下是我尝试过的一些事情，但都失败了。

Question

我几乎要复制/粘贴Apollo GraphQL Network Layer Docs on Creating Middleware中的示例代码，除非我从apollo-client-preset提取我的依赖关系并且我使用简单的实用程序库返回jwt令牌。这是链接代码......

import { ApolloClient, HttpLink, InMemoryCache, ApolloLink, concat } from 'apollo-client-preset';
import { getSessionToken } from './api/localStorage';

const httpLink = new HttpLink({ uri: 'http://localhost:4000/' });

const authMiddleware = new ApolloLink((operation, forward) => {
  const token = getSessionToken();
  const authorizationHeader = token ? `Bearer ${token}` : null;

  operation.setContext({
    headers: {
      authorization: authorizationHeader,
    }
  });

  return forward(operation);
})

const client = new ApolloClient({
  link: concat(authMiddleware, httpLink),
});

这里有./api/localStorage方法......

export const getSessionToken = () => {
    return AsyncStorage.getItem(AUTH_TOKEN);
}

执行上述代码会产生带有以下标题的HTTP请求......

POST / HTTP/1.1
Host: localhost:4000
Content-Type: application/json
User-Agent: Expo/2.2.0.1011489 CFNetwork/893.14 Darwin/17.3.0
Connection: keep-alive
Accept: */*
Accept-Language: en-us
Authorization: Bearer [object Object]
Accept-Encoding: gzip, deflate
Content-Length: 174

注意Authorization: Bearer [object Object]位

我认为问题非常明显。 AsyncStorage是一个异步函数，我需要在组装授权字符串之前等待promise的解析。然而，解决方案不太明显。我尝试了各种方法，但到目前为止还没有爱。

我见过几个与上述类似的例子。这是How to GraphQL Authentication Module中的另一个。两者都没有显示如何等待asyncstorage承诺首先解决。我知道阿波罗有时会自动等待你的承诺，所以我认为这可能就是这种情况。但似乎不符合我的经验。

那么解决方案是什么？

以下是我尝试过的一些事情，但都失败了。

1。 Promise.then（）

const middlewareAuthLink = new ApolloLink((operation, forward) => {
  getSessionToken().then(token => {
    const authorizationHeader = token ? `Bearer ${token}` : null
    operation.setContext({
      headers: {
        authorization: authorizationHeader
      }
    })
  });

  return forward(operation)
})

这确实正确地构造了授权字符串，但似乎没有创建中间件，因为这不会创建授权标头。对我来说，这似乎是我最好的选择，但我必须做错，原因对我来说并不明显。

POST / HTTP/1.1
Host: localhost:4000
Content-Type: application/json
Connection: keep-alive
Accept: */*
User-Agent: Expo/2.2.0.1011489 CFNetwork/893.14 Darwin/17.3.0
Content-Length: 174
Accept-Language: en-us
Accept-Encoding: gzip, deflate

请注意缺少Authorization标题

2。异步/ AWAIT

我认为这很简单，将其变成异步/等待函数，但不是那么多。这是代码

const middlewareAuthLink = new ApolloLink(async (operation, forward) => {
  const token = await getSessionToken();
  const authorizationHeader = token ? `Bearer ${token}` : null;

  operation.setContext({
    headers: {
      authorization: authorizationHeader,
    }
  });
  return forward(operation)
})

但是这导致了这个超级丑陋的红色死亡错误......

Unhandled (in react-apollo:Apollo(EventList)), ApolloError@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:106405:36
currentResult@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:106516:43
dataForChild@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:101608:79
render@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:101659:49
finishClassComponent@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:4528:102
performUnitOfWork@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:5547:33
workLoop@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:5566:142
_invokeGuardedCallback@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:2707:23
invokeGuardedCallback@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:2681:41
performWork@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:5602:41
scheduleUpdateImpl@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:5723:105
enqueueForceUpdate@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:4341:179
forceUpdate@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:8265:38
forceRenderChildren@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:101579:58
next@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:101554:50
error@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:109797:25
forEach@[native code]
error@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:106747:44
http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:107277:47
http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:107649:29
forEach@[native code]
http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:107648:27
forEach@[native code]
broadcastQueries@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:107644:33
http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:107239:51
tryCallOne@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:10901:14
http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:10987:25
_callTimer@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:12157:15
_callImmediatesPass@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:12193:17
callImmediates@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:12397:31
__callImmediates@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:2301:30
http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:2179:32
__guard@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:2287:11
flushedQueue@http://localhost:19001/node_modules/expo/AppEntry.bundle?platform=ios&dev=true&strict=false&minify=false&hot=false&assetPlugin=/Users/ChrisGeirman/dev/mobile/playground/exp/frogquest-app/node_modules/expo/tools/hashAssetFiles:2178:19
flushedQueue@[native code]
invokeCallbackAndReturnFlushedQueue@[native code]

那么如何在设置标题之前等待AsyncStorage的结果返回？

Answer 1

甚至可能有其他解决方案或更好的解决方案，但这最终对我有用，因此我将其发布为已解决。

MSBuildSdksPath

Answer 2

这是从内存中的缓存加载令牌的替代方法，其性能应比从AsyncStorage进行获取更好。另外，您可以简单地使用一个getter包装器函数来缓存来自AsyncStorage的响应，但是将其作为阿波罗缓存的一部分具有更新令牌时重新渲染的额外好处。

import gql from 'graphql-tag'
import ApolloClient from 'apollo-client'
import { setContext } from 'apollo-link-context'
import { createHttpLink } from 'apollo-link-http'
import { InMemoryCache } from 'apollo-cache-inmemory'
import { ApolloLink } from 'apollo-link'
import AsyncStorage from '@react-native-community/async-storage'

const authLink = setContext(async (_, { headers }) => {
  const context = await client.query({
    query: gql`
      query AuthQuery {
        authToken @client
      }
    `
  })
  const {
    data: { authToken: token }
  } = context
  let extra = {}
  if (token) {
    extra = { authorization: `Bearer ${token}` }
  }
  return {
    headers: {
      ...headers,
      ...extra
    }
  }
})

const httpLink = createHttpLink({
  uri: 'http://localhost:4000/'
})

const cache = new InMemoryCache()

const client = new ApolloClient({
  link: ApolloLink.from([authLink, httpLink]),
  cache
})

client.writeData({ data: { authToken: null } })

AsyncStorage.getItem('token').then((token: string | null) => {
  if (token) {
    client.writeData({ data: { authToken: token } })
  }
})

export { client }

从AsyncStorage检索JWT以使用ApolloClient创建httpLink中间件的问题

以下是我尝试过的一些事情，但都失败了。

1。 Promise.then（）

2。异步/ AWAIT

那么如何在设置标题之前等待AsyncStorage的结果返回？

2 个答案: