使用 RX JS 在函数之间进行暂停答案

【问题标题】：Using RX JS to make a pause between functions使用 RX JS 在函数之间进行暂停
【发布时间】：2021-10-06 14:38:18
【问题描述】：

我有一些（大约 10 个左右）对 API 的请求，并且该 API 的限制为每秒 1 个请求。我想使用 RX JS 在每个函数后暂停。我的代码如下所示：

const source = interval(1000);
const getData = async() => { 
    let info = {
        date: new Date(),
        id: initialId,
    };
    if (fetchInitialResponse(initialId) ) { //external function that checks whether entry exists
       info['Names'] = await fetchResponse( getUrl(ADDRESSOTHERNAMES), process.env.OTHERNAMESFOUND);
       info['Address'] = await fetchResponse( getUrl(ADDRESSADDRESS), process.env.ADDRESSFOUND);
       info['Individuals'] = await fetchResponse( getUrl(ADDRESSINDIVIDUALS), process.env.INDIVIDUALSFOUND);
       //and so on with about 10 functions
        mongoConnect(true, info) //external function that writes the recieved info to mongodb 
    }
} 

const subscribe = source.subscribe( () => getData() );

如何在每个 'await fetchResponse' 函数后暂停？

【问题讨论】：

标签： javascript rxjs

【解决方案1】：

这应该将您的调用间隔 1 秒（使用 zip），然后将响应构建到一个信息对象中为您（使用 reduce）。

const initialId = 1234; // Or whatever

const data$ = of({
  date: new Date(),
  id: initialId
}).pipe(
  filter(({id}) => fetchInitialResponse(id)),

  switchMap(info => {
    const apiCalls = [

      from(fetchResponse( 
        getUrl(ADDRESSOTHERNAMES), 
        process.env.OTHERNAMESFOUND
      )).pipe(
        map(names => ({...info, names}))
      ),

      from(fetchResponse( 
        getUrl(ADDRESSADDRESS), 
        process.env.ADDRESSFOUND
      )).pipe(
        map(address => ({...info, address}))
      ),

      from(fetchResponse( 
        getUrl(ADDRESSINDIVIDUALS), 
        process.env.INDIVIDUALSFOUND
      )).pipe(
        map(individuals => ({...info, individuals}))
      ),

      //and so on with about 10 functions
    ];

    return zip(interval(1000), apiCalls);
  }),

  reduce(Object.assign)

).subscribe(info => mongoConnect(true, info));

【讨论】：