Question

我试图通过遍历给定的ID并将其子代附加到树上来构建树结构。它总是分配 user.children ='sample'，而不是从 user.children = usrChild 获取的用户子级，也尝试了 usrArr [index] .children ='sample '

我要实现的目标： 使用userID，我将获取其子项，现在对于每个子项，我将获取其子项，直到没有子项为止。

函数UserProfile.getUserChildren返回包含所有子项的数据的Promise。现在，我们迭代每个孩子并提取他们的孩子

视觉上预期的输出：

从程序上我期望什么：

[
    {   
        text: {
            userID: 1
            name: 'Mike'
        },
        children:[
            {
                text: {
                    userID: 2
                    name: 'John'
                },
                children [
                    {
                        text: {
                            userID: 4
                            name: 'Hero'
                        },
                        children []
                    }
                ]
            },
            {
                text: {
                    userID: 3
                    name: 'Kelvin'
                },
                children []
            }

        ]
    }
]

Node JS中的代码：

let UserProfile = require('./UserProfile');

// Love Dad 83273010
let userID = 51405009;
var allDistributors = Array();
  rootUser = new Object();
  rootUser.text = {userID:userID,name:'Root'};
  rootUser.children = [];
function getUserTree(userID){
  return new Promise( (resolve,reject) => {
    /*
    * UserDownline Return User child Array
    * Format: 
    * [
    *   {   text: {
    *           userID: 45
    *           name: 'Mike'
    *       },
    *       children:[]     
    *   }
    * ]
    * 
    */
     UserProfile.getUserChildren(userID).then(async (data) => {
      if(data.length > 0){
        rootUser.children = data;
        /*
        * Iterating each user to fetch and assign its child
        */
        await rootUser.children.forEach(async (user,index,usrArr) => {

          user.children = 'sample'

          await getUserTree(user.text.title).then( async(usrChild) => {
              /*
                Assigning child to root user
              */
              usrArr[index].children = usrChild; // STILL NOT ABLE TO ASSIGN VALUE and return user.children as 'sample'
          }).then(resolve(rootUser));



        });
        //resolve(rootUser)
        //console.log(rootUser)
        //return Promise.all(rootUser);
      }else
      resolve([]); // return empty child when no child exist
    });
    //return rootUser.children;

    //console.log(rootUser);
  });


}
//console.log(JSON.stringify(rootUser));
getUserTree(userID).then((data) => {
  console.log(JSON.stringify(data));
});

Answer 1

正如Jaromanda X指出的，rootUser.children.foreach返回undefined而不是promise。考虑改用rootUser.children.map。这将返回一个可以使用Promise.all等待的Promises数组，它返回一个数组的Promise。由于map不会修改原始数组，因此您需要将rootUser.children分配给Promise.all

从NodeJS中获取的子详细信息遍历并构建Tree

1 个答案: