zoukankan      html  css  js  c++  java
  • [RxJS] Sharing Streams with Share

    A stream will run with each new subscription added to it. This lesson shows the benefits of using share so that the same stream can be shared across multiple subscriptions.

    const timer$ = starters$
        .switchMap(intervalActions)
        .startWith(data)
        .scan((acc, curr)=> curr(acc))
    
    
    timer$
        .do((x)=> console.log(x))
        .takeWhile((data)=> data.count <= 3)
        .withLatestFrom(
            input$.do((x)=> console.log(x)),
            (timer, input)=> ({count: timer.count, text: input})
        )
        .filter((data)=> data.count === parseInt(data.text))
        .reduce((acc, curr)=> acc + 1, 0)
        .repeat()
        .subscribe(
            (x)=> document.querySelector('#score').innerHTML = `
                ${x}
            `,
            err=> console.log(err),
            ()=> console.log('complete')
        );

    Current code has a problem every time we type in the input, we need to click delete keyborad to delete the input. This is not conveninet. 

    So what we want is every time when the code check whether the value match, then we clean the input:

    const runningGame$ = timer$
        .do((x)=> console.log(x))
        .takeWhile((data)=> data.count <= 3)
        .withLatestFrom(
            input$.do((x)=> console.log(x)),
            (timer, input)=> ({count: timer.count, text: input})
        );
    
    runningGame$
      .subscribe( (x) => input.value = "");
    
     runningGame$
        .filter((data)=> data.count === parseInt(data.text))
        .reduce((acc, curr)=> acc + 1, 0)
        .repeat()
        .subscribe(
            (x)=> document.querySelector('#score').innerHTML = `
                ${x}
            `,
            err=> console.log(err),
            ()=> console.log('complete')
        );

    So we split the code and add another subscribe to clean the input, but now the problem is everytime it console log twice. This is because we have two subscribe on the runningGame$. 

    TO solve this problem, we need to share() the stream:

    const runnintGame$ = timer$
        .do((x)=> console.log(x))
        .takeWhile((data)=> data.count <= 3)
        .withLatestFrom(
            input$.do((x)=> console.log(x)),
            (timer, input)=> ({count: timer.count, text: input})
        )
    .share();

    Now it only log out once, but it doesn't clean the input when we click start again. THis is because we only repeat() this part of code:

     runningGame$
        .filter((data)=> data.count === parseInt(data.text))
        .reduce((acc, curr)=> acc + 1, 0)
        .repeat()

    What we need to do is also make runningGame$ (clean the input) stream repeat itself:

    // To clean the input
    runningGame$
      .repeat()
      .subscribe( (x) => input.value = "");

    ----------------------------

    Code:

    const timer$ = starters$
        .switchMap(intervalActions)
        .startWith(data)
        .scan((acc, curr)=> curr(acc))
    
    
    const runningGame$ = timer$
        .do((x)=> console.log(x))
        .takeWhile((data)=> data.count <= 3)
        .withLatestFrom(
            input$.do((x)=> console.log(x)),
            (timer, input)=> ({count: timer.count, text: input})
        )
    .share();
    
    // To clean the input
    runningGame$
      .repeat()
      .subscribe( (x) => input.value = "");
    
     runningGame$
        .filter((data)=> data.count === parseInt(data.text))
        .reduce((acc, curr)=> acc + 1, 0)
        .repeat()
        .subscribe(
            (x)=> document.querySelector('#score').innerHTML = `
                ${x}
            `,
            err=> console.log(err),
            ()=> console.log('complete')
        );
  • 相关阅读:
    linux 下vi中关于删除某段,某行,或者全部删除的命令
    Crontab的格式
    Crontab的格式
    Eclipse验证码
    jetty插件配置(开发)
    MongoDB使用手册
    Docker学习笔记(1) — docker 常用命令
    debian网易163更新服务器 源
    ssh安装过程
    HTML——列表标签
  • 原文地址:https://www.cnblogs.com/Answer1215/p/5274425.html
Copyright © 2011-2022 走看看