src/lay/modules/form.js
function(){
        var TIPS = '请选择', CLASS = 'layui-form-select', TITLE = 'layui-select-title'
        ,NONE = 'layui-select-none', initValue = '', thatInput
        ,selects = elemForm.find('select')
        
        //隐藏 select
        ,hide = function(e, clear){
          if(!$(e.target).parent().hasClass(TITLE) || clear){
            $('.'+CLASS).removeClass(CLASS+'ed ' + CLASS+'up');
            thatInput && initValue && thatInput.val(initValue);
          }
          thatInput = null;
        }
        
        //各种事件
        ,events = function(reElem, disabled, isSearch){
          var select = $(this)
          ,title = reElem.find('.' + TITLE)
          ,input = title.find('input')
          ,dl = reElem.find('dl')
          ,dds = dl.children('dd')
          ,index =  this.selectedIndex //当前选中的索引
          ,nearElem; //select 组件当前选中的附近元素，用于辅助快捷键功能
          
          if(disabled) return;
          
          //展开下拉
          var showDown = function(){
            var top = reElem.offset().top + reElem.outerHeight() + 5 - $win.scrollTop()
            ,dlHeight = dl.outerHeight();
            
            index = select[0].selectedIndex; //获取最新的 selectedIndex
            reElem.addClass(CLASS+'ed');
            dds.removeClass(HIDE);
            nearElem = null;

            //初始选中样式
            dds.eq(index).addClass(THIS).siblings().removeClass(THIS);

            //上下定位识别
            if(top + dlHeight > $win.height() && top >= dlHeight){
              reElem.addClass(CLASS + 'up');
            }
            
            followScroll();
          }
          
          //隐藏下拉
          ,hideDown = function(choose){
            reElem.removeClass(CLASS+'ed ' + CLASS+'up');
            input.blur();
            nearElem = null;
            
            if(choose) return;
            
            notOption(input.val(), function(none){
              var selectedIndex = select[0].selectedIndex;
              
              //未查询到相关值
              if(none){
                initValue = $(select[0].options[selectedIndex]).html(); //重新获得初始选中值
                
                //如果是第一项，且文本值等于 placeholder，则清空初始值
                if(selectedIndex === 0 && initValue === input.attr('placeholder')){
                  initValue = '';
                };

                //如果有选中值，则将输入框纠正为该值。否则清空输入框
                input.val(initValue || '');
              }
            });
          }
          
          //定位下拉滚动条
          ,followScroll = function(){  
            var thisDd = dl.children('dd.'+ THIS);
            
            if(!thisDd[0]) return;
            
            var posTop = thisDd.position().top
            ,dlHeight = dl.height()
            ,ddHeight = thisDd.height();
            
            //若选中元素在滚动条不可见底部
            if(posTop > dlHeight){
              dl.scrollTop(posTop + dl.scrollTop() - dlHeight + ddHeight - 5);
            }
            
            //若选择玄素在滚动条不可见顶部
            if(posTop < 0){
              dl.scrollTop(posTop + dl.scrollTop() - 5);
            }
          };
          
          //点击标题区域
          title.on('click', function(e){
            reElem.hasClass(CLASS+'ed') ? (
              hideDown()
            ) : (
              hide(e, true), 
              showDown()
            );
            dl.find('.'+NONE).remove();
          }); 
          
          //点击箭头获取焦点
          title.find('.layui-edge').on('click', function(){
            input.focus();
          });
          
          //select 中 input 键盘事件
          input.on('keyup', function(e){ //键盘松开
            var keyCode = e.keyCode;
            
            //Tab键展开
            if(keyCode === 9){
              showDown();
            }
          }).on('keydown', function(e){ //键盘按下
            var keyCode = e.keyCode;

            //Tab键隐藏
            if(keyCode === 9){
              hideDown();
            }
            
            //标注 dd 的选中状态
            var setThisDd = function(prevNext, thisElem1){
              var nearDd, cacheNearElem
              e.preventDefault();

              //得到当前队列元素  
              var thisElem = function(){
                var thisDd = dl.children('dd.'+ THIS);
                
                //如果是搜索状态，且按 Down 键，且当前可视 dd 元素在选中元素之前，
                //则将当前可视 dd 元素的上一个元素作为虚拟的当前选中元素，以保证递归不中断
                if(dl.children('dd.'+  HIDE)[0] && prevNext === 'next'){
                  var showDd = dl.children('dd:not(.'+ HIDE +',.'+ DISABLED +')')
                  ,firstIndex = showDd.eq(0).index();
                  if(firstIndex >=0 && firstIndex < thisDd.index() && !showDd.hasClass(THIS)){
                    return showDd.eq(0).prev()[0] ? showDd.eq(0).prev() : dl.children(':last');
                  }
                }

                if(thisElem1 && thisElem1[0]){
                  return thisElem1;
                }
                if(nearElem && nearElem[0]){
                  return nearElem;
                }
       
                return thisDd;
                //return dds.eq(index);
              }();
              
              cacheNearElem = thisElem[prevNext](); //当前元素的附近元素
              nearDd =  thisElem[prevNext]('dd:not(.'+ HIDE +')'); //当前可视元素的 dd 元素

              //如果附近的元素不存在，则停止执行，并清空 nearElem
              if(!cacheNearElem[0]) return nearElem = null;
              
              //记录附近的元素，让其成为下一个当前元素
              nearElem = thisElem[prevNext]();

              //如果附近不是 dd ，或者附近的 dd 元素是禁用状态，则进入递归查找
              if((!nearDd[0] || nearDd.hasClass(DISABLED)) && nearElem[0]){
                return setThisDd(prevNext, nearElem);
              }
              
              nearDd.addClass(THIS).siblings().removeClass(THIS); //标注样式
              followScroll(); //定位滚动条
            };
            
            if(keyCode === 38) setThisDd('prev'); //Up 键
            if(keyCode === 40) setThisDd('next'); //Down 键
            
            //Enter 键
            if(keyCode === 13){ 
              e.preventDefault();
              dl.children('dd.'+THIS).trigger('click');
            }
          });
          
          //检测值是否不属于 select 项
          var notOption = function(value, callback, origin){
            var num = 0;
            layui.each(dds, function(){
              var othis = $(this)
              ,text = othis.text()
              ,not = text.indexOf(value) === -1;
              if(value === '' || (origin === 'blur') ? value !== text : not) num++;
              origin === 'keyup' && othis[not ? 'addClass' : 'removeClass'](HIDE);
            });
            var none = num === dds.length;
            return callback(none), none;
          };
          
          //搜索匹配
          var search = function(e){
            var value = this.value, keyCode = e.keyCode;
            
            if(keyCode === 9 || keyCode === 13 
              || keyCode === 37 || keyCode === 38 
              || keyCode === 39 || keyCode === 40
            ){
              return false;
            }
            
            notOption(value, function(none){
              if(none){
                dl.find('.'+NONE)[0] || dl.append('<p class="'+ NONE +'">无匹配项</p>');
              } else {
                dl.find('.'+NONE).remove();
              }
            }, 'keyup');
            
            if(value === ''){
              dl.find('.'+NONE).remove();
            }
            
            followScroll(); //定位滚动条
          };
          
          if(isSearch){
            input.on('keyup', search).on('blur', function(e){
              var selectedIndex = select[0].selectedIndex;
              
              thatInput = input; //当前的 select 中的 input 元素
              initValue = $(select[0].options[selectedIndex]).html(); //重新获得初始选中值
              
              //如果是第一项，且文本值等于 placeholder，则清空初始值
              if(selectedIndex === 0 && initValue === input.attr('placeholder')){
                initValue = '';
              };
              
              setTimeout(function(){
                notOption(input.val(), function(none){
                  initValue || input.val(''); //none && !initValue
                }, 'blur');
              }, 200);
            });
          }

          //选择
          dds.on('click', function(){
            var othis = $(this), value = othis.attr('lay-value');
            var filter = select.attr('lay-filter'); //获取过滤器
            
            if(othis.hasClass(DISABLED)) return false;
            
            if(othis.hasClass('layui-select-tips')){
              input.val('');
            } else {
              input.val(othis.text());
              othis.addClass(THIS);
            }

            othis.siblings().removeClass(THIS);
            select.val(value).removeClass('layui-form-danger')
            layui.event.call(this, MOD_NAME, 'select('+ filter +')', {
              elem: select[0]
              ,value: value
              ,othis: reElem
            });

            hideDown(true);
            return false;
          });
          
          reElem.find('dl>dt').on('click', function(e){
            return false;
          });
          
          $(document).off('click', hide).on('click', hide); //点击其它元素关闭 select
        }
        
        selects.each(function(index, select){
          var othis = $(this)
          ,hasRender = othis.next('.'+CLASS)
          ,disabled = this.disabled
          ,value = select.value
          ,selected = $(select.options[select.selectedIndex]) //获取当前选中项
          ,optionsFirst = select.options[0];
          
          if(typeof othis.attr('lay-ignore') === 'string') return othis.show();
          
          var isSearch = typeof othis.attr('lay-search') === 'string'
          ,placeholder = optionsFirst ? (
            optionsFirst.value ? TIPS : (optionsFirst.innerHTML || TIPS)
          ) : TIPS;

          //替代元素
          var reElem = $(['<div class="'+ (isSearch ? '' : 'layui-unselect ') + CLASS 
          ,(disabled ? ' layui-select-disabled' : '') +'">'
            ,'<div class="'+ TITLE +'">'
              ,('<input type="text" placeholder="'+ placeholder +'" '
                +('value="'+ (value ? selected.html() : '') +'"') //默认值
                +(isSearch ? '' : ' readonly') //是否开启搜索
                +' class="layui-input'
                +(isSearch ? '' : ' layui-unselect') 
              + (disabled ? (' ' + DISABLED) : '') +'">') //禁用状态
            ,'<i class="layui-edge"></i></div>'
            ,'<dl class="layui-anim layui-anim-upbit'+ (othis.find('optgroup')[0] ? ' layui-select-group' : '') +'">'
            ,function(options){
              var arr = [];
              layui.each(options, function(index, item){
                if(index === 0 && !item.value){
                  arr.push('<dd lay-value="" class="layui-select-tips">'+ (item.innerHTML || TIPS) +'</dd>');
                } else if(item.tagName.toLowerCase() === 'optgroup'){
                  arr.push('<dt>'+ item.label +'</dt>'); 
                } else {
                  arr.push('<dd lay-value="'+ item.value +'" class="'+ (value === item.value ?  THIS : '') + (item.disabled ? (' '+DISABLED) : '') +'">'+ item.innerHTML +'</dd>');
                }
              });
              arr.length === 0 && arr.push('<dd lay-value="" class="'+ DISABLED +'">没有选项</dd>');
              return arr.join('');
            }(othis.find('*')) +'</dl>'
          ,'</div>'].join(''));
          
          hasRender[0] && hasRender.remove(); //如果已经渲染，则Rerender
          othis.after(reElem);          
          events.call(this, reElem, disabled, isSearch);
        });
      }
function(){
        var TIPS = '请选择', CLASS = 'layui-form-select', TITLE = 'layui-select-title'
        ,NONE = 'layui-select-none', initValue = '', thatInput
        ,selects = elemForm.find('select')
        
        //隐藏 select
        ,hide = function(e, clear){
          if(!$(e.target).parent().hasClass(TITLE) || clear){
            $('.'+CLASS).removeClass(CLASS+'ed ' + CLASS+'up');
            thatInput && initValue && thatInput.val(initValue);
          }
          thatInput = null;
        }
        
        //各种事件
        ,events = function(reElem, disabled, isSearch){
          var select = $(this)
          ,title = reElem.find('.' + TITLE)
          ,input = title.find('input')
          ,dl = reElem.find('dl')
          ,dds = dl.children('dd')
          ,index =  this.selectedIndex //当前选中的索引
          ,nearElem; //select 组件当前选中的附近元素，用于辅助快捷键功能
          
          if(disabled) return;
          
          //展开下拉
          var showDown = function(){
            var top = reElem.offset().top + reElem.outerHeight() + 5 - $win.scrollTop()
            ,dlHeight = dl.outerHeight();
            
            index = select[0].selectedIndex; //获取最新的 selectedIndex
            reElem.addClass(CLASS+'ed');
            dds.removeClass(HIDE);
            nearElem = null;

            //初始选中样式
            dds.eq(index).addClass(THIS).siblings().removeClass(THIS);

            //上下定位识别
            if(top + dlHeight > $win.height() && top >= dlHeight){
              reElem.addClass(CLASS + 'up');
            }
            
            followScroll();
          }
          
          //隐藏下拉
          ,hideDown = function(choose){
            reElem.removeClass(CLASS+'ed ' + CLASS+'up');
            input.blur();
            nearElem = null;
            
            if(choose) return;
            
            notOption(input.val(), function(none){
              var selectedIndex = select[0].selectedIndex;
              
              //未查询到相关值
              if(none){
                initValue = $(select[0].options[selectedIndex]).html(); //重新获得初始选中值
                
                //如果是第一项，且文本值等于 placeholder，则清空初始值
                if(selectedIndex === 0 && initValue === input.attr('placeholder')){
                  initValue = '';
                };

                //如果有选中值，则将输入框纠正为该值。否则清空输入框
                input.val(initValue || '');
              }
            });
          }
          
          //定位下拉滚动条
          ,followScroll = function(){  
            var thisDd = dl.children('dd.'+ THIS);
            
            if(!thisDd[0]) return;
            
            var posTop = thisDd.position().top
            ,dlHeight = dl.height()
            ,ddHeight = thisDd.height();
            
            //若选中元素在滚动条不可见底部
            if(posTop > dlHeight){
              dl.scrollTop(posTop + dl.scrollTop() - dlHeight + ddHeight - 5);
            }
            
            //若选择玄素在滚动条不可见顶部
            if(posTop < 0){
              dl.scrollTop(posTop + dl.scrollTop() - 5);
            }
          };
          
          //点击标题区域
          title.on('click', function(e){
            reElem.hasClass(CLASS+'ed') ? (
              hideDown()
            ) : (
              hide(e, true), 
              showDown()
            );
            dl.find('.'+NONE).remove();
          }); 
          
          //点击箭头获取焦点
          title.find('.layui-edge').on('click', function(){
            input.focus();
          });
          
          //select 中 input 键盘事件
          input.on('keyup', function(e){ //键盘松开
            var keyCode = e.keyCode;
            
            //Tab键展开
            if(keyCode === 9){
              showDown();
            }
          }).on('keydown', function(e){ //键盘按下
            var keyCode = e.keyCode;

            //Tab键隐藏
            if(keyCode === 9){
              hideDown();
            }
            
            //标注 dd 的选中状态
            var setThisDd = function(prevNext, thisElem1){
              var nearDd, cacheNearElem
              e.preventDefault();

              //得到当前队列元素  
              var thisElem = function(){
                var thisDd = dl.children('dd.'+ THIS);
                
                //如果是搜索状态，且按 Down 键，且当前可视 dd 元素在选中元素之前，
                //则将当前可视 dd 元素的上一个元素作为虚拟的当前选中元素，以保证递归不中断
                if(dl.children('dd.'+  HIDE)[0] && prevNext === 'next'){
                  var showDd = dl.children('dd:not(.'+ HIDE +',.'+ DISABLED +')')
                  ,firstIndex = showDd.eq(0).index();
                  if(firstIndex >=0 && firstIndex < thisDd.index() && !showDd.hasClass(THIS)){
                    return showDd.eq(0).prev()[0] ? showDd.eq(0).prev() : dl.children(':last');
                  }
                }

                if(thisElem1 && thisElem1[0]){
                  return thisElem1;
                }
                if(nearElem && nearElem[0]){
                  return nearElem;
                }
       
                return thisDd;
                //return dds.eq(index);
              }();
              
              cacheNearElem = thisElem[prevNext](); //当前元素的附近元素
              nearDd =  thisElem[prevNext]('dd:not(.'+ HIDE +')'); //当前可视元素的 dd 元素

              //如果附近的元素不存在，则停止执行，并清空 nearElem
              if(!cacheNearElem[0]) return nearElem = null;
              
              //记录附近的元素，让其成为下一个当前元素
              nearElem = thisElem[prevNext]();

              //如果附近不是 dd ，或者附近的 dd 元素是禁用状态，则进入递归查找
              if((!nearDd[0] || nearDd.hasClass(DISABLED)) && nearElem[0]){
                return setThisDd(prevNext, nearElem);
              }
              
              nearDd.addClass(THIS).siblings().removeClass(THIS); //标注样式
              followScroll(); //定位滚动条
            };
            
            if(keyCode === 38) setThisDd('prev'); //Up 键
            if(keyCode === 40) setThisDd('next'); //Down 键
            
            //Enter 键
            if(keyCode === 13){ 
              e.preventDefault();
              dl.children('dd.'+THIS).trigger('click');
            }
          });
          
          //检测值是否不属于 select 项
          var notOption = function(value, callback, origin){
            var num = 0;
            layui.each(dds, function(){
              var othis = $(this)
              ,text = othis.text()
              ,not = text.indexOf(value) === -1;
              if(value === '' || (origin === 'blur') ? value !== text : not) num++;
              origin === 'keyup' && othis[not ? 'addClass' : 'removeClass'](HIDE);
            });
            var none = num === dds.length;
            return callback(none), none;
          };
          
          //搜索匹配
          var search = function(e){
            var value = this.value, keyCode = e.keyCode;
            
            if(keyCode === 9 || keyCode === 13 
              || keyCode === 37 || keyCode === 38 
              || keyCode === 39 || keyCode === 40
            ){
              return false;
            }
            
            notOption(value, function(none){
              if(none){
                dl.find('.'+NONE)[0] || dl.append('<p class="'+ NONE +'">无匹配项</p>');
              } else {
                dl.find('.'+NONE).remove();
              }
            }, 'keyup');
            
            if(value === ''){
              dl.find('.'+NONE).remove();
            }
            
            followScroll(); //定位滚动条
          };
          
          if(isSearch){
            input.on('keyup', search).on('blur', function(e){
              var selectedIndex = select[0].selectedIndex;
              
              thatInput = input; //当前的 select 中的 input 元素
              initValue = $(select[0].options[selectedIndex]).html(); //重新获得初始选中值
              
              //如果是第一项，且文本值等于 placeholder，则清空初始值
              if(selectedIndex === 0 && initValue === input.attr('placeholder')){
                initValue = '';
              };
              
              setTimeout(function(){
                notOption(input.val(), function(none){
                  initValue || input.val(''); //none && !initValue
                }, 'blur');
              }, 200);
            });
          }

          //选择
          dds.on('click', function(){
            var othis = $(this), value = othis.attr('lay-value');
            var filter = select.attr('lay-filter'); //获取过滤器
            
            if(othis.hasClass(DISABLED)) return false;
            
            if(othis.hasClass('layui-select-tips')){
              input.val('');
            } else {
              input.val(othis.text());
              othis.addClass(THIS);
            }

            othis.siblings().removeClass(THIS);
            select.val(value).removeClass('layui-form-danger')
            layui.event.call(this, MOD_NAME, 'select('+ filter +')', {
              elem: select[0]
              ,value: value
              ,othis: reElem
            });

            hideDown(true);
            return false;
          });
          
          reElem.find('dl>dt').on('click', function(e){
            return false;
          });
          
          $(document).off('click', hide).on('click', hide); //点击其它元素关闭 select
        }
        
        selects.each(function(index, select){
          var othis = $(this)
          ,hasRender = othis.next('.'+CLASS)
          ,disabled = this.disabled
          ,value = select.value
          ,selected = $(select.options[select.selectedIndex]) //获取当前选中项
          ,optionsFirst = select.options[0];
          
          if(typeof othis.attr('lay-ignore') === 'string') return othis.show();
          
          var isSearch = typeof othis.attr('lay-search') === 'string'
          ,placeholder = optionsFirst ? (
            optionsFirst.value ? TIPS : (optionsFirst.innerHTML || TIPS)
          ) : TIPS;

          //替代元素
          var reElem = $(['<div class="'+ (isSearch ? '' : 'layui-unselect ') + CLASS 
          ,(disabled ? ' layui-select-disabled' : '') +'">'
            ,'<div class="'+ TITLE +'">'
              ,('<input type="text" placeholder="'+ placeholder +'" '
                +('value="'+ (value ? selected.html() : '') +'"') //默认值
                +(isSearch ? '' : ' readonly') //是否开启搜索
                +' class="layui-input'
                +(isSearch ? '' : ' layui-unselect') 
              + (disabled ? (' ' + DISABLED) : '') +'">') //禁用状态
            ,'<i class="layui-edge"></i></div>'
            ,'<dl class="layui-anim layui-anim-upbit'+ (othis.find('optgroup')[0] ? ' layui-select-group' : '') +'">'
            ,function(options){
              var arr = [];
              layui.each(options, function(index, item){
                if(index === 0 && !item.value){
                  arr.push('<dd lay-value="" class="layui-select-tips">'+ (item.innerHTML || TIPS) +'</dd>');
                } else if(item.tagName.toLowerCase() === 'optgroup'){
                  arr.push('<dt>'+ item.label +'</dt>'); 
                } else {
                  arr.push('<dd lay-value="'+ item.value +'" class="'+ (value === item.value ?  THIS : '') + (item.disabled ? (' '+DISABLED) : '') +'">'+ item.innerHTML +'</dd>');
                }
              });
              arr.length === 0 && arr.push('<dd lay-value="" class="'+ DISABLED +'">没有选项</dd>');
              return arr.join('');
            }(othis.find('*')) +'</dl>'
          ,'</div>'].join(''));
          
          hasRender[0] && hasRender.remove(); //如果已经渲染，则Rerender
          othis.after(reElem);          
          events.call(this, reElem, disabled, isSearch);
        });
      }
下拉选择框