如何从一个 DOM 事件中为两个流供电

Question

表单有一个保存按钮。单击时它应该路由到另一个组件并保存表单数据。但是 router$ stream 消耗了 click 事件，而 socket$ stream 没有事件可以采取行动。在下面的代码中，saveClick$ 仅适用于 router$ 但不适用于 socket$。

import sampleCombine from 'xstream/extra/sampleCombine'
import parent from '../../../util/parent'
import xs from 'xstream'
import dataRequest from './dataRequest'

export default ({DOM, onion, props$}) => {
  const saveClick$ = DOM
    .select('.MetaNav__Save')
    .events('click')

  return {
    router$: xs.merge(
      DOM.select('.MetaNav__Cancel')
        .events('click')
        .compose(sampleCombine(onion.state$)),
      saveClick$
        .compose(sampleCombine(onion.state$))
      )
      .map(([e, state]) => `/album/${window.btoa(parent(state.id))}`),
    socket$: saveClick$
      .compose(sampleCombine(onion.state$))
      .map(([e, state]) => ({
        messageType: 'graphql',
        message: `mutation {
          setInfo(info: {title: "${document.getElementById('MetaTitle').value}", description: "${document.getElementById('MetaDescription').value}", favorite: ${document.getElementById('MetaFavorite').checked.toString()}}, id: "${state.id}") {
            id
          }
        }`
      }))
      .startWith(dataRequest(props$))
  }
}

如何获得由同一事件支持的两个流？ imitate() 似乎可以解决问题，但文档说它存在

to allow one thing: circular dependency of streams

这是一个非常基本的用例。感觉好像我缺少一些基本的东西。感谢帮助。

Answer 1

在发送到 router$ 之前复制 saveClick$。

import sampleCombine from 'xstream/extra/sampleCombine'
import parent from '../../../util/parent'
import xs from 'xstream'
import dataRequest from './dataRequest'

export default ({DOM, onion, props$}) => {

  const saveClick$ = DOM.select('.MetaNav__Save')
    .events('click')

  const saveClickSocket$ = saveClick$
    .compose(sampleCombine(onion.state$))
    .map(([e, state]) => ({
      messageType: 'graphql',
      message: `mutation {setInfo(info: {title: "${document.getElementById('MetaTitle').value}", description: "${document.getElementById('MetaDescription').value}", favorite: ${document.getElementById('MetaFavorite').checked.toString()}}, id: "${state.id}") {id}}`
    }))
    .startWith(dataRequest(props$))

  const allClick$ = xs.merge(
    DOM.select('.MetaNav__Cancel')
      .events('click')
      .compose(sampleCombine(onion.state$)),
    saveClick$,
      .compose(sampleCombine(onion.state$))
  )
    .map(([e, state]) => `/album/${window.btoa(parent(state.id))}`),

  return {
    router$: allClick$,
    socket$: saveClickSocket$
  }
}

为清晰起见重构流构造：

const saveClick$ = DOM.select('.MetaNav__Save')
  .events('click')
  .compose(sampleCombine(onion.state$))

const cancelClick$ = DOM.select('.MetaNav__Cancel')
  .events('click')
  .compose(sampleCombine(onion.state$))

const saveClickSocket$ = saveClick$
  .map(([e, state]) => ({
    messageType: 'graphql',
    message: `mutation {setInfo(info: {title: "${document.getElementById('MetaTitle').value}", description: "${document.getElementById('MetaDescription').value}", favorite: ${document.getElementById('MetaFavorite').checked.toString()}}, id: "${state.id}") {id}}`
  }))
  .startWith(dataRequest(props$))

const allClick$ = xs.merge(
  cancelClicks,
  saveClick$,
)
  .map(([e, state]) => `/album/${window.btoa(parent(state.id))}`),

Answer 2

这是一个错误的问题。看评论...

如何从一个 DOM 事件中为两个流供电

how to power two streams from one DOM event

cyclejs

xstream-js