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我创建了一个类foo的元素。然后我打算在发生单击事件后将其类与bar交换。但是，当我单击元素时，订阅了foo和bar的单击事件的流被连续触发。结果，元素的类没有改变。如何订阅其类随时间变化的同一元素的事件？

这是链接：

https://jsbin.com/kanomonexa/edit?html,js,控制台,输出

这是示例代码：

const {div, button, makeDOMDriver} = CycleDOM;
const toggleDriver = (data$)=> {
    data$.subscribe(function(data) {
        if (data.operation === 'remove' ) {
            $(data.selector).removeClass(data.className);
        }
        else if (data.operation === 'add') {
            $(data.selector).addClass(data.className);
        }
        else {
            $(data.selector).toggle(data.className);
        }

    });

    return Rx.Observable.empty();
};

const consoleLogDriver = (data$)=>{
  data$.subscribe(data=> {
        console.log(data);
  });

  return Rx.Observable.empty();
};

const main = (sources) =>{
  const fooClick$ = sources.DOM
  .select('.foo')
  .events('click');
  const fooLog$ = fooClick$.map(_ =>'.foo is Clicked');
  const toggleFoo$ = fooClick$.flatMap(_ => {
    const result = [
      {
        operation: 'remove',
        selector: 'button',
        className: 'foo'
      },
      {
        operation: 'add',
        selector: 'button',
        className: 'bar'
      }
    ];
    return Rx.Observable.fromArray(result);
  });
  
  const barClick$ = sources.DOM
  .select('.bar')
  .events('click');
  const barLog$ = barClick$.map(_ => '.bar is Clicked');
  const toggleBar$ = barClick$.flatMap(_ =>{
    const result = [
      {
        operation: 'remove',
        selector: 'button',
        className: 'bar'
      },
      {
        operation: 'add',
        selector: 'button',
        className: 'foo'
      }
    ];
    return Rx.Observable.fromArray(result);
  });
  
  const log$ = Rx.Observable.merge(
    fooLog$,
    barLog$
  );
  const toggle$ = Rx.Observable.merge(
    toggleFoo$,
    toggleBar$
  );
  
  const vTree$ = Rx.Observable.of(div([
    button('#button.foo',['Click me'])
    
  ]));
  
  return {
    DOM: vTree$,
    consoleLogDriver: log$,
    toggleDriver:toggle$
  };
};

var drivers = {
  DOM: makeDOMDriver('#app'),
  toggleDriver: toggleDriver,
  consoleLogDriver: consoleLogDriver
};

Cycle.run(main, drivers);
<!DOCTYPE html>
<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/4.0.6/rx.all.js"></script>
<script src="https://code.jquery.com/jquery-2.1.4.js"></script>
<script src="https://rawgit.com/cyclejs/cycle-core/v6.0.3/dist/cycle.js"></script>
<script src="https://rawgit.com/cyclejs/cycle-dom/v9.4.0/dist/cycle-dom.js"></script>

  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>
<div id="app"></div>
</body>
</html>

4

1 回答 1

1

您可以delay(0)通过 toggle$ 流将其值安排到下一个事件循环，然后成功更改您的 className：

...
const toggle$ = Observable.merge(...)
  .delay(0)
...

我看到您正在使用 Jquery 来切换您的课程。根据你想做的事情，我想它可能有一些有用的情况（例如：在页面中的其他地方切换一个类，使其超出虚拟 dom 的范围）。

但是你的循环应用程序是由虚拟 dom 处理的，所以我建议你使用正确的工具来完成这项工作，而不是在每次更改时重建你的 vtree$：

...
const currentClassName$ = Rx.Observable
  .merge(
    fooClick$.map(_ => '.bar'),
    barClick$.map(_ => '.foo')
  )
  .delay(0) // fix the bug
  .startWith('.foo');

const vTree$ = currentClassName$
  .map(currentClassName => 
    div([
      button(
        '#button' + currentClassName, ['Click me']
      )
    ]));
...

工作演示

于 2016-04-22T13:21:39.883 回答