fix(carousel): 修复动态删除条目至最后一个时调用 inst.reload 的异常问题 (#2107)

* fix(carousel): 修复外部动态增删条目时调用 inst.reload 的异常问题

* chore: 更正命名，避免歧义

* fix: 修复 slide 方法在条目数为 1 的滑动异常问题

examples/carousel.html

@@ -68,54 +68,56 @@ div[carousel-item]>*:nth-child(2n+1){background-color: #5FB878;}
 layui.use('carousel', function(){
   var carousel = layui.carousel;
   
-  //建造实例
-  carousel.render({
-    elem: '#test1'
-    ,index: 2
-    //,full: true
-    ,arrow: 'always'
-    ,autoplay: 'always'
-    ,change: function(obj){
+  // 实例
+  var carInst = carousel.render({
+    elem: '#test1',
+    index: 2,
+    // full: true,
+    arrow: 'always',
+    autoplay: 'always',
+    change: function(obj) {
       console.log(obj)
-    }
-    //,interval: 5000
-    //,autoplay: false
-    //,indicator: 'outside'
-    //,trigger: 'hover'
+    },
+    // interval: 5000,
+    // autoplay: false,
+    // indicator: 'outside',
+    // trigger: 'hover'
   });
+
+  // carInst.goto(1);
   
-  //事件
+  // 事件
   /*
-  carousel.on('change(test1)', function(obj){
+  carousel.on('change(test1)', function(obj) {
     console.log(obj)
   });
   */
 
   carousel.render({
-    elem: '#test2'
-    ,interval: 1800
-    //,full: true
-    ,anim: 'fade'
-    ,height: '120px'
+    elem: '#test2',
+    interval: 1800,
+    // full: true,
+    anim: 'fade',
+    height: '120px'
   });
   
   carousel.render({
-    elem: '#test3'
-    //,full: true
-    ,arrow: 'always'
-    //,autoplay: false
-    //,indicator: 'outside'
-    //,trigger: 'hover'
-    ,anim: 'updown'
-    //,full: true
+    elem: '#test3',
+    // full: true,
+    arrow: 'always',
+    // autoplay: false,
+    // indicator: 'outside',
+    // trigger: 'hover',
+    anim: 'updown',
+    // full: true
   });
   
   // 图片轮播
   carousel.render({
-    elem: '#test4'
-    ,width: '720px'
-    ,height: '360px'
-    ,interval: 5000
+    elem: '#test4',
+    width: '720px',
+    height: '360px',
+    interval: 5000
   });
 });
 </script>

src/modules/carousel.js

@@ -113,13 +113,14 @@ layui.define(['jquery', 'lay'], function(exports){
     // 初始焦点状态
     that.elemItem.eq(options.index).addClass(THIS);
 
-    // 指示器等动作
-    if(that.elemItem.length <= 1) return;
-
+    // 指示器、箭头等动作
     that.indicator();
     that.arrow();
     that.autoplay();
-    that.events();
+
+    if (that.elemItem.length > 1) {
+      that.events();
+    }
   };
   
   // 重置轮播
@@ -188,19 +189,23 @@ layui.define(['jquery', 'lay'], function(exports){
   Class.prototype.autoplay = function(){
     var that = this;
     var options = that.config;
+    var itemsCount = that.elemItem.length;
     
     if(!options.autoplay) return;
     clearInterval(that.timer);
     
-    that.timer = setInterval(function(){
-      that.slide();
-    }, options.interval);
+    if (itemsCount > 1) {
+      that.timer = setInterval(function(){
+        that.slide();
+      }, options.interval);
+    }
   };
   
   // 箭头
   Class.prototype.arrow = function(){
     var that = this;
     var options = that.config;
+    var itemsCount = that.elemItem.length;
     
     // 模板
     var tplArrow = $([
@@ -215,7 +220,7 @@ layui.define(['jquery', 'lay'], function(exports){
     if(options.elem.find('.'+ELEM_ARROW)[0]){
       options.elem.find('.'+ELEM_ARROW).remove();
     }
-    options.elem.append(tplArrow);
+    itemsCount > 1 ? options.elem.append(tplArrow) : tplArrow.remove();
     
     // 事件
     tplArrow.on('click', function(){
@@ -241,6 +246,7 @@ layui.define(['jquery', 'lay'], function(exports){
   Class.prototype.indicator = function(){
     var that = this;
     var options = that.config;
+    var itemsCount = that.elemItem.length;
     
     // 模板
     var tplInd = that.elemInd = $(['<div class="'+ ELEM_IND +'"><ul>',
@@ -260,7 +266,8 @@ layui.define(['jquery', 'lay'], function(exports){
     if(options.elem.find('.'+ELEM_IND)[0]){
       options.elem.find('.'+ELEM_IND).remove();
     }
-    options.elem.append(tplInd);
+
+    itemsCount > 1 ? options.elem.append(tplInd) : tplInd.remove();
     
     if(options.anim === 'updown'){
       tplInd.css('margin-top', -(tplInd.height()/2));
@@ -276,11 +283,12 @@ layui.define(['jquery', 'lay'], function(exports){
   Class.prototype.slide = function(type, num){
     var that = this;
     var elemItem = that.elemItem;
+    var itemsCount = elemItem.length;
     var options = that.config;
     var thisIndex = options.index;
     var filter = options.elem.attr('lay-filter');
     
-    if(that.haveSlide) return;
+    if (that.haveSlide || itemsCount <= 1) return;
     
     // 滑动方向
     if(type === 'sub'){
@@ -329,6 +337,7 @@ layui.define(['jquery', 'lay'], function(exports){
     var options = that.config;
     
     if(options.elem.data('haveEvents')) return;
+
     
     // 移入移出容器
     options.elem.on('mouseenter touchstart', function(){