我有一些赛车蜜蜂。在我的Redux商店中,它们是具有名称属性和可能性属性的数组中的对象。对于每只蜜蜂,我想计算其获胜的可能性。计算算法是异步。当我启动所有蜜蜂的计算时,蜜蜂的可能性属性应具有"计算"的值,当蜜蜂的计算完成时,可能性属性应显示一个数字。
我有一个无法修改的函数generateBeeWinLikelihoodCalculator
。
现在,我的代码无法分别计算出蜜蜂获胜的可能性,而我为如何最好地实现这一目标而感到不知所措。我想到将Calcultinglikelihood函数派遣到每个Bee实例并在还原器中调用,但是如何将其返回"计算...",然后当Settimeout运行时,然后返回值?p>
let state = {bees:[{name: 'marie'},{name: 'john'}]}
const reducer = (state, action) => {
switch (action.type) {
case 'FETCH_BEES':
return {
...state,
bees: action.bees,
}
case 'RUN_CALCULATIONS':
return {
...state,
bees: state.bees.map(bee => {
bee.likelihood = action.likelihood
return bee
})
}
case 'DISPLAY_CALCULATIONS':
return {
...state,
bees: state.bees.map(bee => {
bee.likelihood = action.likelihood
return bee
})
}
default: return state
}
}
const runCalculations = (likelihood) => ({
type: 'RUN_CALCULATIONS',
likelihood,
})
const displayCalculations = (likelihood) => ({
type: 'DISPLAY_CALCULATIONS',
likelihood,
})
const store = {
dispatch: (action) => {
state = reducer(state,action)
return state
},
getState: () => {
return state
}
}
//this calculator cannot be modified
const generateBeeWinLikelihoodCalculator = () => {
var delay = 1000 + Math.random() * 1000;
var likelihoodOfAntWinning = Math.random();
return function(callback) {
setTimeout(function() {
callback(likelihoodOfAntWinning)
}, delay);
};
}
const calculatingLikelihood = () => {
store.dispatch(runCalculations('calculating...'))
console.log(JSON.stringify(store.getState()))
const callback = (likelihoodOfBeeWinning) => {
store.dispatch(displayCalculations(likelihoodOfBeeWinning))
console.log(JSON.stringify(store.getState()))
}
return generateBeeWinLikelihoodCalculator()(callback)
}
calculatingLikelihood()
我也会给蜜蜂一个id属性,并将它们作为蜜蜂的地图存储为iD与蜜蜂数组。这使得在状态下更新单个蜜蜂。
您也可以使用诺言或异步/等待。
因此状态变为:
让state = {bees:{1:{id:1,name:'marie'},2:{id:2 name:'john'}}
// Grab the list of Bees
const bees = store.getState().bees
// Work on each bee and update it individually
Object.values(bees).forEach(async bee => {
const likelihood = await calculate(bee)
store.dispatch({ type: 'UPDATE_BEE', payload: { ...bee, likelihood } })
})
// Or you could wait for all calculations to resolve before updating state
const promises = Object.values(bees).map(async bee => {
const likelihood = await calculate(bee)
return { ...bee, likelihood }
})
Promise.all(promises).then(bees => {
store.dispatch({ type: 'UPDATE_BEES', payload: _.keyBy(bees, 'id') })
})