javascript - 将子类别添加到类别数组

Question

我有一个Category对象，每个Category都有SubCategories。为每个Category加载其SubCategories的正确方法是什么？

const getCategories = async () => {
  const { data: categories } = await axios.get(`api/Categories/GetCategories`); 
  return categories;
};

const getSubCategories = async catId => {
  const { data: subCategories } = await axios.get(`../api/SubCategories/GetSubCategories?catId=${catId}`); 
  return subCategories;
};

Answer 1

这是一种简单但次优的方法，因为缺乏异步性。

const categories = getCategories().map(category => {
    return {
        category
        , subCategory: getSubCategories(category.catId)
    }
})

更好的方法是从 getSubCategories 中删除 await 并让它只返回 promise 。

const getSubCategories = async catId => axios.get(`../api/SubCategories/GetSubCategories?catId=${catId}`)

当您返回 Promise 时，它​​们可以异步运行。

const categories = getCategories()

如果您使用的是异步函数，您可以执行以下操作:

const subCategories = await Promise.all(categories.map(category => getSubCategories(category.catId))
const categoriesWithSub = zipWith(categories, subCategories, (category, subCategory) => ({category, subCategory}))

否则

Promise.all(categories.map(category => getSubCategories(category.catId))
.then(subCategories => {
    const categoriesWithSub = zipWith(categories, subCategories, (category, subCategory) => ({category, subCategory}))
})

categoriesWithSub 是具有以下形状的对象数组。

[{
    category: {} // however your original category object looked like.
    , subCategory: [] // The array of subCategories for this category.
}]