ant-design-vue/es/vc-tree/useMaxLevel.js

An enterprise-class UI design language and Vue-based implementation

import { shallowRef, ref, watchEffect } from 'vue';
export default function useMaxLevel(keyEntities) {
  var maxLevel = ref(0);
  var levelEntities = shallowRef();
  watchEffect(function () {
    var newLevelEntities = new Map();
    var newMaxLevel = 0;
    var keyEntitiesValue = keyEntities.value || {}; // Convert entities by level for calculation

    for (var key in keyEntitiesValue) {
      if (Object.prototype.hasOwnProperty.call(keyEntitiesValue, key)) {
        var entity = keyEntitiesValue[key];
        var level = entity.level;
        var levelSet = newLevelEntities.get(level);

        if (!levelSet) {
          levelSet = new Set();
          newLevelEntities.set(level, levelSet);
        }

        levelSet.add(entity);
        newMaxLevel = Math.max(newMaxLevel, level);
      }
    }

    maxLevel.value = newMaxLevel;
    levelEntities.value = newLevelEntities;
  });
  return {
    maxLevel: maxLevel,
    levelEntities: levelEntities
  };
}