examSystem-Anxin/src/app/http-interceptors/tree.service.ts

import { Injectable } from '@angular/core';

@Injectable()
export class TreeService {


    toTree(olddata) {
        let newdata = []
        function getparentNode(parentId) {
            return olddata.find((item) => {
                return item.id == parentId
            })
        }
        olddata.forEach(item => {
            item.key = item.id
            item.title = item.name
            var parentNode = getparentNode(item.parentId);
            if (parentNode) {
                if (!parentNode.children) {
                    parentNode.children = []
                }

                if (parentNode.children.length == 0) {
                    item.isTop = true;
                } else {
                    item.isTop = false;
                    parentNode.children[parentNode.children.length - 1].isBottom = false;
                }
                item.isBottom = true;

                parentNode.children.push(item)
            } else {
                if (!item.parentId) {//如果parentId为null
                    newdata.push(item)
                }
            }
        });
        return newdata;
    }
}