LayUi 树形组件tree 实现懒加载模式，展开父节点时异步加载子节点数据

如题。

效果图：

 //lazy属性为true，点开时才加载

 

 

 

引用代码：

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tree-define.js文件：

/**
   * [tree 树形组件]
   * @param  {[type]}  layid   [过滤器ID]
   * @param  {[type]}  data    [数据]
   * @param  {[type]}  showCheckbox [复选框]
   * @param  {[type]}  showLine [连接线]
   * @param  {[type]}  accordion [手风琴模式]
   * @param  {[type]}  onlyIconControl [图标控制展开]
   * @param  {[type]}  isJump [新窗口跳转]
   */
layui.use('tree', function () {
    var $ = layui.$;
    datatree = function (layid, data, showCheckbox, showLine, accordion, onlyIconControl, isJump) {
        if (layid) {
            var _data = data || [];
            var _showCheckbox = showCheckbox || false; //是否显示复选框
            var _showLine = showLine || true; //是否开启连接线。默认 true，若设为 false，则节点左侧出现三角图标。
            var _accordion = accordion || false; //是否开启手风琴模式，默认 false
            var _onlyIconControl = onlyIconControl || false; //是否仅允许节点左侧图标控制展开收缩。默认 false
            var _isJump = isJump || false; //是否允许点击节点时弹出新窗口跳转。默认 false
            var result = {
                onclick: function () { },
                oncheck: function () { },
                onspread: function () { },
                getChecked: function () { },
                setChecked: function () { },
                reload: function () { }
            }
        
                var tree = layui.tree;
                var inst1 = tree.render({
                    elem: '#' + layid,
                    id: layid, //定义索引
                    showCheckbox: _showCheckbox,
                    showLine: _showLine,
                    accordion: _accordion,
                    onlyIconControl: _onlyIconControl,
                    isJump: _isJump,
                    data: _data,
                    text: {
                        defaultNodeName: '无数据',
                        none: '加载数据失败！'
                    },
                    click: function (obj) {
                        
                        result.onclick.call(obj);
                        if (!_showCheckbox) {
                            $('#' + layid).find('.layui-tree-click').removeClass('layui-tree-click');
                            obj.elem.find('span.layui-tree-txt:first').addClass('layui-tree-click');
                        }
                         //console.log(obj.data); //得到当前点击的节点数据
                        // console.log(obj.state); //得到当前节点的展开状态：open、close、normal
                         //console.log(obj.elem); //得到当前节点元素
                        // console.log(obj.data.children); //当前节点下是否有子节点
                    },
                    oncheck: function (obj) {
                        result.oncheck.call(obj);
                        //console.log(obj.data); //得到当前点击的节点数据
                        // console.log(obj.checked); //得到当前节点的展开状态：open、close、normal
                        // console.log(obj.elem); //得到当前节点元素
                    },
                    spread: function (obj) {
                        if (obj.state == 'open') {
                            obj.lazytree = function (data) {
                                tree.lazytree(inst1.config.id, obj.elem, data);
                            }
                            result.onspread.call(obj);
                        }
                    }
                });
                result.getChecked = function () {
                    if (_showCheckbox) {
                        var checkData = tree.getChecked(layid);
                        return checkData;
                    }
                    else {
                        var check = $('#' + layid).find('.layui-tree-click');
                        if (check.length > 0) {
                            return { id: check.parent().parent().parent().attr('data-id') }
                        }
                    }
                }
                result.setChecked = function (data) {
                    if (_showCheckbox) {
                        tree.setChecked(layid, data);
                    }
                }
                result.reload = function () {
                    tree.reload(layid, {});
                }
        
            return result;
        }
    }
});

重写的tree.js:

/**
 
 @Name：layui.tree 树
 @Author：star1029，（一如既往修改2019-12-11 17:09:35）
 @License：MIT

 */

layui.define('form', function(exports){
  "use strict";
  
  var $ = layui.$
  ,form = layui.form
  ,layer = layui.layer
  
  //模块名
  ,MOD_NAME = 'tree'

  //外部接口
  ,tree = {
    config: {}
    ,index: layui[MOD_NAME] ? (layui[MOD_NAME].index + 10000) : 0

    //设置全局项
    ,set: function(options){
      var that = this;
      that.config = $.extend({}, that.config, options);
      return that;
    }
    
    //事件监听
    ,on: function(events, callback){
      return layui.onevent.call(this, MOD_NAME, events, callback);
    }
  }

  //操作当前实例
  ,thisModule = function(){
    var that = this
    ,options = that.config
    ,id = options.id || that.index;
    
    thisModule.that[id] = that; //记录当前实例对象
    thisModule.config[id] = options; //记录当前实例配置项
    
    return {
      config: options
      //重置实例
      ,reload: function(options){
        that.reload.call(that, options);
      }
      ,getChecked: function(){
        return that.getChecked.call(that);
      }
      ,setChecked: function(id){//设置值
        return that.setChecked.call(that, id);
      }
      ,lazytree: function(elem, children){
        return that.tree.lazytree(that, elem, children);
      }
    }
  }
  
  //获取当前实例配置项
  ,getThisModuleConfig = function(id){
    var config = thisModule.config[id];
    if(!config) hint.error('The ID option was not found in the '+ MOD_NAME +' instance');
    return config || null;
  }

  //字符常量
  ,SHOW = 'layui-show', HIDE = 'layui-hide', NONE = 'layui-none', DISABLED = 'layui-disabled'
  
  ,ELEM_VIEW = 'layui-tree', ELEM_SET = 'layui-tree-set', ICON_CLICK = 'layui-tree-iconClick'
  ,ICON_ADD = 'layui-icon-addition', ICON_SUB = 'layui-icon-subtraction', ELEM_ENTRY = 'layui-tree-entry', ELEM_MAIN = 'layui-tree-main', ELEM_TEXT = 'layui-tree-txt', ELEM_PACK = 'layui-tree-pack', ELEM_SPREAD = 'layui-tree-spread'
  ,ELEM_LINE_SHORT = 'layui-tree-setLineShort', ELEM_SHOW = 'layui-tree-showLine', ELEM_EXTEND = 'layui-tree-lineExtend', ELEM_INIT = '.layui-tree-init'
 
  //构造器
  ,Class = function(options){
    var that = this;
    that.index = ++tree.index;
    that.config = $.extend({}, that.config, tree.config, options);
    that.render();
  };

  //默认配置
  Class.prototype.config = {
    data: []  //数据
    
    ,showCheckbox: false  //是否显示复选框
    ,showLine: true  //是否开启连接线
    ,accordion: false  //是否开启手风琴模式
    ,onlyIconControl: false  //是否仅允许节点左侧图标控制展开收缩
    ,isJump: false  //是否允许点击节点时弹出新窗口跳转
    ,edit: false  //是否开启节点的操作图标
    ,loading: true //请求数据时，是否显示loading
    
    ,text: {
      defaultNodeName: '未命名' //节点默认名称
      ,none: '无数据'  //数据为空时的文本提示
    }
  };
  
  //重载实例
  Class.prototype.reload = function(options){
    var that = this;
    
    layui.each(options, function(key, item){
      if(item.constructor === Array) delete that.config[key];
    });
    
    that.config = $.extend(true, {}, that.config, options);
    that.render();
  };

  //主体渲染
  Class.prototype.render = function(){
    var that = this
    ,options = that.config;
    
    that.checkids = [];

    var temp = $('
');
    that.tree(temp);

    var othis = options.elem = $(options.elem);
    if(!othis[0]) return;

    //索引
    that.key = options.id || that.index;
    
    //插入组件结构
    that.elem = temp;
    that.elemNone = $('
'+ options.text.none +'
');
    othis.html(that.elem);

    if(that.elem.find('.layui-tree-set').length == 0){
      return that.elem.append(that.elemNone);
    };
    
    //复选框渲染
    if(options.showCheckbox){
      that.renderForm('checkbox');
    };

    that.elem.find('.layui-tree-set').each(function(){
      var othis = $(this);
      //最外层
      if(!othis.parent('.layui-tree-pack')[0]){
        othis.addClass('layui-tree-setHide');
      };

      //没有下一个节点 上一层父级有延伸线
      if(!othis.next()[0] && othis.parents('.layui-tree-pack').eq(1).hasClass('layui-tree-lineExtend')){
        othis.addClass(ELEM_LINE_SHORT);
      };
      
      //没有下一个节点 外层最后一个
      if(!othis.next()[0] && !othis.parents('.layui-tree-set').eq(0).next()[0]){
        othis.addClass(ELEM_LINE_SHORT);
      };
    });

    that.events();
  };
  
  //渲染表单
  Class.prototype.renderForm = function(type){
    form.render(type, 'LAY-tree-'+ this.index);
  };

  //节点解析
  Class.prototype.tree = function(elem, children){
    var that = this
    ,options = that.config
    ,data = children || options.data;

    //遍历数据
    layui.each(data, function(index, item){
      var hasChild = item.children && item.children.length > 0
      ,packDiv = $('
')
      ,entryDiv = $(['
'
        ,'
'
          ,'
'
            //箭头
            ,function(){
              if(options.showLine){
                if(hasChild || item.lazy){ //lazy 是否开启懒加载，需要配合spread事件使用
                  return '';
                }else{
                  return '';
                };
              }else{
                return '';
              };
            }()
            
            //复选框
            ,function(){
              return options.showCheckbox ? '' : '';
            }()
            
            //节点
            ,function(){
              if(options.isJump && item.href){
                return ''+ (item.title || item.label || options.text.defaultNodeName) +'';
              }else{
                return ''+ (item.title || item.label || options.text.defaultNodeName) +'';
              }
            }()
      ,'
'
      
      //节点操作图标
      ,function(){
        if(!options.edit) return '';
        
        var editIcon = {
          add: ''
          ,update: ''
          ,del: ''
        }, arr = ['
'];
        
        if(options.edit === true){
          options.edit = ['update', 'del']
        }
        
        if(typeof options.edit === 'object'){
          layui.each(options.edit, function(i, val){
            arr.push(editIcon[val] || '')
          });
          return arr.join('') + '
';
        }
      }()
      ,'
'].join(''));

      //如果有子节点，则递归继续生成树
      if(hasChild){
        entryDiv.append(packDiv);
        that.tree(packDiv, item.children);
      };

      elem.append(entryDiv);
      
      //若有前置节点，前置节点加连接线
      if(entryDiv.prev('.'+ELEM_SET)[0]){
        entryDiv.prev().children('.layui-tree-pack').addClass('layui-tree-showLine');
      };
      
      //若无子节点，则父节点加延伸线
      if(!hasChild){
        entryDiv.parent('.layui-tree-pack').addClass('layui-tree-lineExtend');
      };

      //展开节点操作
      that.spread(entryDiv, item);
      
      //选择框
      if(options.showCheckbox){
        item.checked && that.checkids.push(item.id);
        that.checkClick(entryDiv, item);
      }
      
      //操作节点
      options.edit && that.operate(entryDiv, item);
      
    });
  };

  //懒加载节点
  Class.prototype.lazytree = function(elem, children){
    var that = this
    ,options = that.config
    ,id = elem.attr('data-id');
    var change = function(data){
      layui.each(data, function(index, e){
        if(e.id===id){
          data[index].children = children;
          return false;
        }
        if(e.children && e.children.length > 0){
          change(e.children);
        }
      });
    }
    //追加数据
    change(options.data);
    that.loading(elem, true);
    var packDiv = $('
');
    elem.append(packDiv);
    that.tree(packDiv, children);
    //复选框渲染
    if(options.showCheckbox){
      that.renderForm('checkbox');
    };
  }

  //请求loading
  Class.prototype.loading = function(elem, hide){
    var that = this
    ,options = that.config;
    if(options.loading){
      if(hide){
        that.layInit && that.layInit.remove();
        delete that.layInit;
        that.elem.find(ELEM_INIT).remove();
      } else {
        that.layInit = $(['
'
          ,''
        ,'
'].join(''));
        elem.append(that.layInit);
      }
    }
  };

  //展开节点
  Class.prototype.spread = function(elem, item){
    var that = this
    ,options = that.config
    ,entry = elem.children('.'+ELEM_ENTRY)
    ,elemMain = entry.children('.'+ ELEM_MAIN)
    ,elemIcon = entry.find('.'+ ICON_CLICK)
    ,elemText = entry.find('.'+ ELEM_TEXT)
    ,touchOpen = options.onlyIconControl ? elemIcon : elemMain //判断展开通过节点还是箭头图标
    ,state = '';
    
    //展开收缩
    touchOpen.on('click', function(e){
      if(that.layInit) return false;
      var packCont = elem.children('.'+ELEM_PACK)
      ,iconClick = touchOpen.children('.layui-icon')[0] ? touchOpen.children('.layui-icon') : touchOpen.find('.layui-tree-icon').children('.layui-icon');

      //若没有子节点
      if(!packCont[0]){
        state = 'normal';
      }else{
        if(elem.hasClass(ELEM_SPREAD)){
          elem.removeClass(ELEM_SPREAD);
          packCont.slideUp(200);
          iconClick.removeClass(ICON_SUB).addClass(ICON_ADD); 
        }else{
          elem.addClass(ELEM_SPREAD);
          packCont.slideDown(200);
          iconClick.addClass(ICON_SUB).removeClass(ICON_ADD);

          //是否手风琴
          if(options.accordion){
            var sibls = elem.siblings('.'+ELEM_SET);
            sibls.removeClass(ELEM_SPREAD);
            sibls.children('.'+ELEM_PACK).slideUp(200);
            sibls.find('.layui-tree-icon').children('.layui-icon').removeClass(ICON_SUB).addClass(ICON_ADD);
          };
        };
      };

      //展开产生的回调
      if(state==='normal' && item.lazy){
        var _spread = elem.hasClass(ELEM_SPREAD);
        if(elem.hasClass(ELEM_SPREAD)){
          elem.removeClass(ELEM_SPREAD);
          packCont.slideUp(200);
          iconClick.removeClass(ICON_SUB).addClass(ICON_ADD); 
        }else{
          elem.addClass(ELEM_SPREAD);
          packCont.slideDown(200);
          iconClick.addClass(ICON_SUB).removeClass(ICON_ADD);

          //是否手风琴
          if(options.accordion){
            var sibls = elem.siblings('.'+ELEM_SET);
            sibls.removeClass(ELEM_SPREAD);
            sibls.children('.'+ELEM_PACK).slideUp(200);
            sibls.find('.layui-tree-icon').children('.layui-icon').removeClass(ICON_SUB).addClass(ICON_ADD);
          };
        };
        //判断展开收缩状态
        if(elem.hasClass(ELEM_SPREAD)){
          state = 'open';
        } else {
          state = 'close';
        }
        options.spread && options.spread({
          elem: elem
          ,state: state
          ,data: item
        });
        that.loading(elem);
      }
      
    });
    
    //点击回调
    elemText.on('click', function(){
      var othis = $(this);
      
      //判断是否禁用状态
      if(othis.hasClass(DISABLED)) return;
      
      //判断展开收缩状态
      if(elem.hasClass(ELEM_SPREAD)){
        state = options.onlyIconControl ? 'open' : 'close';
      } else {
        state = options.onlyIconControl ? 'close' : 'open';
      }
      
      //点击产生的回调
      options.click && options.click({
        elem: elem
        ,state: state
        ,data: item
      });
    });
  };
  
  //计算复选框选中状态
  Class.prototype.setCheckbox = function(elem, item, elemCheckbox){
    var that = this
    ,options = that.config
    ,checked = elemCheckbox.prop('checked');
    
    if(elemCheckbox.prop('disabled')) return;

    //同步子节点选中状态
    if(typeof item.children === 'object' || elem.find('.'+ELEM_PACK)[0]){
      var childs = elem.find('.'+ ELEM_PACK).find('input[same="layuiTreeCheck"]');
      childs.each(function(){
        if(this.disabled) return; //不可点击则跳过
        this.checked = checked;
      });
    };

    //同步父节点选中状态
    var setParentsChecked = function(thisNodeElem){
      //若无父节点，则终止递归
      if(!thisNodeElem.parents('.'+ ELEM_SET)[0]) return;

      var state
      ,parentPack = thisNodeElem.parent('.'+ ELEM_PACK)
      ,parentNodeElem = parentPack.parent()
      ,parentCheckbox =  parentPack.prev().find('input[same="layuiTreeCheck"]');

      //如果子节点有任意一条选中，则父节点为选中状态
      if(checked){
        parentCheckbox.prop('checked', checked);
      } else { //如果当前节点取消选中，则根据计算“兄弟和子孙”节点选中状态，来同步父节点选中状态
        parentPack.find('input[same="layuiTreeCheck"]').each(function(){
          if(this.checked){
            state = true;
          }
        });
        
        //如果兄弟子孙节点全部未选中，则父节点也应为非选中状态
        state || parentCheckbox.prop('checked', false);
      }
      
      //向父节点递归
      setParentsChecked(parentNodeElem);
    };
    
    setParentsChecked(elem);

    that.renderForm('checkbox');
  };
  
  //复选框选择
  Class.prototype.checkClick = function(elem, item){
    var that = this
    ,options = that.config
    ,entry = elem.children('.'+ ELEM_ENTRY)
    ,elemMain = entry.children('.'+ ELEM_MAIN);
    
    
    
    //点击复选框
    elemMain.on('click', 'input[same="layuiTreeCheck"]+', function(e){
      layui.stope(e); //阻止点击节点事件

      var elemCheckbox = $(this).prev()
      ,checked = elemCheckbox.prop('checked');
      
      if(elemCheckbox.prop('disabled')) return;
      
      that.setCheckbox(elem, item, elemCheckbox);

      //复选框点击产生的回调
      options.oncheck && options.oncheck({
        elem: elem
        ,checked: checked
        ,data: item
      });
    });
  };

  //节点操作
  Class.prototype.operate = function(elem, item){
    var that = this
    ,options = that.config
    ,entry = elem.children('.'+ ELEM_ENTRY)
    ,elemMain = entry.children('.'+ ELEM_MAIN);

    entry.children('.layui-tree-btnGroup').on('click', '.layui-icon', function(e){
      layui.stope(e);  //阻止节点操作

      var type = $(this).data("type")
      ,packCont = elem.children('.'+ELEM_PACK)
      ,returnObj = {
        data: item
        ,type: type
        ,elem:elem
      };
      //增加
      if(type == 'add'){
        //若节点本身无子节点
        if(!packCont[0]){
          //若开启连接线，更改图标样式
          if(options.showLine){
            elemMain.find('.'+ICON_CLICK).addClass('layui-tree-icon');
            elemMain.find('.'+ICON_CLICK).children('.layui-icon').addClass(ICON_ADD).removeClass('layui-icon-file');
          //若未开启连接线，显示箭头
          }else{
            elemMain.find('.layui-tree-iconArrow').removeClass(HIDE);
          };
          //节点添加子节点容器
          elem.append('
');
        };

        //新增节点
        var key = options.operate && options.operate(returnObj)
        ,obj = {};
        obj.title = options.text.defaultNodeName;
        obj.id = key;
        that.tree(elem.children('.'+ELEM_PACK), [obj]);
        
        //放在新增后面，因为要对元素进行操作
        if(options.showLine){
          //节点本身无子节点
          if(!packCont[0]){
            //遍历兄弟节点，判断兄弟节点是否有子节点
            var siblings = elem.siblings('.'+ELEM_SET), num = 1
            ,parentPack = elem.parent('.'+ELEM_PACK);
            layui.each(siblings, function(index, i){
              if(!$(i).children('.'+ELEM_PACK)[0]){
                num = 0;
              };
            });

            //若兄弟节点都有子节点
            if(num == 1){
              //兄弟节点添加连接线
              siblings.children('.'+ELEM_PACK).addClass(ELEM_SHOW);
              siblings.children('.'+ELEM_PACK).children('.'+ELEM_SET).removeClass(ELEM_LINE_SHORT);
              elem.children('.'+ELEM_PACK).addClass(ELEM_SHOW);
              //父级移除延伸线
              parentPack.removeClass(ELEM_EXTEND);
              //同层节点最后一个更改线的状态
              parentPack.children('.'+ELEM_SET).last().children('.'+ELEM_PACK).children('.'+ELEM_SET).last().addClass(ELEM_LINE_SHORT);
            }else{
              elem.children('.'+ELEM_PACK).children('.'+ELEM_SET).addClass(ELEM_LINE_SHORT);
            };
          }else{
            //添加延伸线
            if(!packCont.hasClass(ELEM_EXTEND)){
              packCont.addClass(ELEM_EXTEND);
            };
            //子节点添加延伸线
            elem.find('.'+ELEM_PACK).each(function(){
              $(this).children('.'+ELEM_SET).last().addClass(ELEM_LINE_SHORT);
            });
            //如果前一个节点有延伸线
            if(packCont.children('.'+ELEM_SET).last().prev().hasClass(ELEM_LINE_SHORT)){
              packCont.children('.'+ELEM_SET).last().prev().removeClass(ELEM_LINE_SHORT);
            }else{
              //若之前的没有，说明处于连接状态
              packCont.children('.'+ELEM_SET).last().removeClass(ELEM_LINE_SHORT);
            };
            //若是最外层，要始终保持相连的状态
            if(!elem.parent('.'+ELEM_PACK)[0] && elem.next()[0]){
              packCont.children('.'+ELEM_SET).last().removeClass(ELEM_LINE_SHORT);
            };
          };
        };
        if(!options.showCheckbox) return;
        //若开启复选框，同步新增节点状态
        if(elemMain.find('input[same="layuiTreeCheck"]')[0].checked){
          var packLast = elem.children('.'+ELEM_PACK).children('.'+ELEM_SET).last();
          packLast.find('input[same="layuiTreeCheck"]')[0].checked = true;
        };
        that.renderForm('checkbox');
      
      //修改
      }else if(type == 'update'){
        var text = elemMain.children('.'+ ELEM_TEXT).html();
        elemMain.children('.'+ ELEM_TEXT).html('');
        //添加输入框，覆盖在文字上方
        elemMain.append('');
        //获取焦点
        elemMain.children('.layui-tree-editInput').val(text).focus();
        //嵌入文字移除输入框
        var getVal = function(input){
          var textNew = input.val().trim();
          textNew = textNew ? textNew : options.text.defaultNodeName;
          input.remove();
          elemMain.children('.'+ ELEM_TEXT).html(textNew);
          
          //同步数据
          returnObj.data.title = textNew;
          
          //节点修改的回调
          options.operate && options.operate(returnObj);
        };
        //失去焦点
        elemMain.children('.layui-tree-editInput').blur(function(){
          getVal($(this));
        });
        //回车
        elemMain.children('.layui-tree-editInput').on('keydown', function(e){
          if(e.keyCode === 13){
            e.preventDefault();
            getVal($(this));
          };
        });

      //删除
      } else {
        layer.confirm('确认删除该节点 "'+ (item.title || '') +'" 吗？', function(index){
          options.operate && options.operate(returnObj); //节点删除的回调
          returnObj.status = 'remove'; //标注节点删除
          
          layer.close(index);
          
          //若删除最后一个，显示空数据提示
          if(!elem.prev('.'+ELEM_SET)[0] && !elem.next('.'+ELEM_SET)[0] && !elem.parent('.'+ELEM_PACK)[0]){
            elem.remove();
            that.elem.append(that.elemNone);
            return;
          };
          //若有兄弟节点
          if(elem.siblings('.'+ELEM_SET).children('.'+ELEM_ENTRY)[0]){
            //若开启复选框
            if(options.showCheckbox){
              //若开启复选框，进行下步操作
              var elemDel = function(elem){
                //若无父结点，则不执行
                if(!elem.parents('.'+ELEM_SET)[0]) return;
                var siblingTree = elem.siblings('.'+ELEM_SET).children('.'+ELEM_ENTRY)
                ,parentTree = elem.parent('.'+ELEM_PACK).prev()
                ,checkState = parentTree.find('input[same="layuiTreeCheck"]')[0]
                ,state = 1, num = 0;
                //若父节点未勾选
                if(checkState.checked == false){
                  //遍历兄弟节点
                  siblingTree.each(function(i, item1){
                    var input = $(item1).find('input[same="layuiTreeCheck"]')[0]
                    if(input.checked == false && !input.disabled){
                      state = 0;
                    };
                    //判断是否全为不可勾选框
                    if(!input.disabled){
                      num = 1;
                    };
                  });
                  //若有可勾选选择框并且已勾选
                  if(state == 1 && num == 1){
                    //勾选父节点
                    checkState.checked = true;
                    that.renderForm('checkbox');
                    //向上遍历祖先节点
                    elemDel(parentTree.parent('.'+ELEM_SET));
                  };
                };
              };
              elemDel(elem);
            };
            //若开启连接线
            if(options.showLine){
              //遍历兄弟节点，判断兄弟节点是否有子节点
              var siblings = elem.siblings('.'+ELEM_SET), num = 1
              ,parentPack = elem.parent('.'+ELEM_PACK);
              layui.each(siblings, function(index, i){
                if(!$(i).children('.'+ELEM_PACK)[0]){
                  num = 0;
                };
              });
              //若兄弟节点都有子节点
              if(num == 1){
                //若节点本身无子节点
                if(!packCont[0]){
                  //父级去除延伸线，因为此时子节点里没有空节点
                  parentPack.removeClass(ELEM_EXTEND);
                  siblings.children('.'+ELEM_PACK).addClass(ELEM_SHOW);
                  siblings.children('.'+ELEM_PACK).children('.'+ELEM_SET).removeClass(ELEM_LINE_SHORT);
                };
                //若为最后一个节点
                if(!elem.next()[0]){
                  elem.prev().children('.'+ELEM_PACK).children('.'+ELEM_SET).last().addClass(ELEM_LINE_SHORT);
                }else{
                  parentPack.children('.'+ELEM_SET).last().children('.'+ELEM_PACK).children('.'+ELEM_SET).last().addClass(ELEM_LINE_SHORT);
                };
                //若为最外层最后一个节点，去除前一个结点的连接线
                if(!elem.next()[0] && !elem.parents('.'+ELEM_SET)[1] && !elem.parents('.'+ELEM_SET).eq(0).next()[0]){
                  elem.prev('.'+ELEM_SET).addClass(ELEM_LINE_SHORT);
                };
              }else{
                //若为最后一个节点且有延伸线
                if(!elem.next()[0] && elem.hasClass(ELEM_LINE_SHORT)){
                  elem.prev().addClass(ELEM_LINE_SHORT);
                };
              };
            };
          
          }else{
            //若无兄弟节点
            var prevDiv = elem.parent('.'+ELEM_PACK).prev();
            //若开启了连接线
            if(options.showLine){
              prevDiv.find('.'+ICON_CLICK).removeClass('layui-tree-icon');
              prevDiv.find('.'+ICON_CLICK).children('.layui-icon').removeClass(ICON_SUB).addClass('layui-icon-file');
              //父节点所在层添加延伸线
              var pare = prevDiv.parents('.'+ELEM_PACK).eq(0);
              pare.addClass(ELEM_EXTEND);

              //兄弟节点最后子节点添加延伸线
              pare.children('.'+ELEM_SET).each(function(){
                $(this).children('.'+ELEM_PACK).children('.'+ELEM_SET).last().addClass(ELEM_LINE_SHORT);
              });
            }else{
            //父节点隐藏箭头
              prevDiv.find('.layui-tree-iconArrow').addClass(HIDE);
            };
            //移除展开属性
            elem.parents('.'+ELEM_SET).eq(0).removeClass(ELEM_SPREAD);
            //移除节点容器
            elem.parent('.'+ELEM_PACK).remove();
          };

          elem.remove();
        });
        
      };
    });
  };

  //部分事件
  Class.prototype.events = function(){
    var that = this
    ,options = that.config
    ,checkWarp = that.elem.find('.layui-tree-checkedFirst');
    
    //初始选中
    that.setChecked(that.checkids);
    
    //搜索
    that.elem.find('.layui-tree-search').on('keyup', function(){
      var input = $(this)
      ,val = input.val()
      ,pack = input.nextAll()
      ,arr = [];

      //遍历所有的值
      pack.find('.'+ ELEM_TEXT).each(function(){
        var entry = $(this).parents('.'+ELEM_ENTRY);
        //若值匹配，加一个类以作标识
        if($(this).html().indexOf(val) != -1){
          arr.push($(this).parent());
          
          var select = function(div){
            div.addClass('layui-tree-searchShow');
            //向上父节点渲染
            if(div.parent('.'+ELEM_PACK)[0]){
              select(div.parent('.'+ELEM_PACK).parent('.'+ELEM_SET));
            };
          };
          select(entry.parent('.'+ELEM_SET));
        };
      });

      //根据标志剔除
      pack.find('.'+ELEM_ENTRY).each(function(){
        var parent = $(this).parent('.'+ELEM_SET);
        if(!parent.hasClass('layui-tree-searchShow')){
          parent.addClass(HIDE);
        };
      });
      if(pack.find('.layui-tree-searchShow').length == 0){
        that.elem.append(that.elemNone);
      };

      //节点过滤的回调
      options.onsearch && options.onsearch({
        elem: arr
      });
    });

    //还原搜索初始状态
    that.elem.find('.layui-tree-search').on('keydown', function(){
      $(this).nextAll().find('.'+ELEM_ENTRY).each(function(){
        var parent = $(this).parent('.'+ELEM_SET);
        parent.removeClass('layui-tree-searchShow '+ HIDE);
      });
      if($('.layui-tree-emptyText')[0]) $('.layui-tree-emptyText').remove();
    });
  };

  //得到选中节点
  Class.prototype.getChecked = function(){
    var that = this
    ,options = that.config
    ,checkId = []
    ,checkData = [];
    
    //遍历节点找到选中索引
    that.elem.find('.layui-form-checked').each(function(){
      checkId.push($(this).prev()[0].value);
    });
    
    //遍历节点
    var eachNodes = function(data, checkNode){
      layui.each(data, function(index, item){
        layui.each(checkId, function(index2, item2){
          if(item.id == item2){
            var cloneItem = $.extend({}, item);
            delete cloneItem.children;
            
            checkNode.push(cloneItem);
            
            if(item.children){
              cloneItem.children = [];
              eachNodes(item.children, cloneItem.children);
            }
            return true
          }
        });
      });
    };

    eachNodes($.extend({}, options.data), checkData);
    
    return checkData;
  };

  //设置选中节点
  Class.prototype.setChecked = function(checkedId){
    var that = this
    ,options = that.config;

    //初始选中
    that.elem.find('.'+ELEM_SET).each(function(i, item){
      var thisId = $(this).data('id')
      ,input = $(item).children('.'+ELEM_ENTRY).find('input[same="layuiTreeCheck"]')
      ,reInput = input.next();
      
      //若返回数字
      if(typeof checkedId === 'number'){
        if(thisId == checkedId){
          if(!input[0].checked){
            reInput.click();
          };
          return false;
        };
      } 
      //若返回数组
      else if(typeof checkedId === 'object'){
        layui.each(checkedId, function(index, value){
          if(value == thisId && !input[0].checked){
            reInput.click();
            return true;
          }
        });
      };
    });
  };

  //记录所有实例
  thisModule.that = {}; //记录所有实例对象
  thisModule.config = {}; //记录所有实例配置项
  
  //重载实例
  tree.reload = function(id, options){
    var that = thisModule.that[id];
    that.reload(options);
    
    return thisModule.call(that);
  };
  
  //获得选中的节点数据
  tree.getChecked = function(id){
    var that = thisModule.that[id];
    return that.getChecked();
  };
  
  //设置选中节点
  tree.setChecked = function(id, checkedId){
    var that = thisModule.that[id];
    return that.setChecked(checkedId);
  };

  //懒加载增加节点
  tree.lazytree = function(id, elem, children){
    var that = thisModule.that[id];
    return that.lazytree(elem, children);
  };
    
  //核心入口
  tree.render = function(options){
    var inst = new Class(options);
    return thisModule.call(inst);
  };

  exports(MOD_NAME, tree);
})

扩展这个tree.js的原作者链接：https://www.cnblogs.com/han1982/p/11535627.html#!comments

【HG-Layui-UI通用后台管理框架V1.0版】

下载地址：

https://www.cnblogs.com/han1982/p/12003454.html