打字稿:等待所有承诺

Question

我的承诺遇到了一个小问题.

这是我的功能:

public generateMealPlanForAWeek(myMealProfile: any, totalCalories:number):Promise<any> {
        return new Promise(resolve => {
            let mealplan:Array<any> = [];
            for (let i = 1; i <= 7; i++) {
                this.generateMealPlanForOneDay(myMealProfile, totalCalories).then(data => {
                    mealplan.push(data); // resolves much later
                });
            }
            resolve(mealplan); // is resolved instant
        })
    }

我的问题是,"generateMealPlanForOneDay"将在之后的膳食计划本身得到解决.

Mealplan是一系列物体(在这种情况下是用餐).

当我想保存我的膳食计划时,膳食计划是空的:

this.storage.set('Mealplan', JSON.stringify(mealplan)).then(....) // meal plan is Array[0]

什么是解决我的膳食计划的所有膳食然后保存它的最佳方法？

Answer 1

你可以Promise.all在这种情况下使用.

public generateMealPlanForAWeek(myMealProfile: any, totalCalories:number):Promise<any> {
    var mealPlans = [];
    for (let i = 1; i <= 7; i++) {
       mealPlans.push(this.generateMealPlanForOneDay(myMealProfile, totalCalories));
    }
    return Promise.all(mealPlans);
}

// later
generateMealPlanForAWeek(...).then(mealPlans => ...);