New features

• Backtop
  • Add Backtop component (#15541 by @iamkun)
• PageHeader
  • Add PageHeader component (#15714 by @ziyoung)
• InfiniteScroll
  • Add InfiniteScroll directive (#15567 by @iamkun)
• Cascader
  • Add multiple mode and filter-method (#15611 by @SimonaliaChen)
• Message
  • Display in stack mode (#15639 by @island205)
• Tag
  • Add prop effect (#15725 by @SimonaliaChen)
• Tabs
  • Left align title when type is card (#15695 by @luckyCao)
• DatePicker
  • Support literal strings (#15525 by @island205)
• Image
  • Add support for transmit attrs and listeners (#15578 by @VanMess)
• Theme
  • Add popup background (#15412 by @iamkun)
• Chore
  • Update new 2.9.0 index page (#15682 by @iamkun)

Bug fixes

• Table
  • Fix sort-change behaviour when sort condition is null (#15012 by @joelxr)
• Image
  • Fix ssr and object-fit compatibility (#15346 by @SimonaliaChen)
• Input
  • Fix show-word-count style in el-form (#15359 by @lvjiaxuan)
  • Fix clear icon is not centered (#15354 by @YiiGuxing)
• Calendar
  • Fix not correct day of week when the day is Sunday (#15399 by @qingdengyue)
  • Fix October disappear bug (#15394 by @qingdengyue)
• Tabs
  • Fix basic tab nested in card tab padding error (#15461 by @SimonaliaChen)
• Tag
  • Fix stop propagation problem (#15150 by @infjer)
• Form
  • Fix input-group within form-item height error (#15457 by @SimonaliaChen)
  • Fix resetFields issue (15181 by @luckyCao)
• Tooltip
  • Fix custom tabindex not work (#15619 by @SimonaliaChen )
• Link
  • Fix link icon style class (#15752 by @iamkun)
• Select
  • Revert set value to null when cleared (#15447 by @iamkun)
• Loading
  • Fix dom not change when loading state change quickly (#15123 by @FAKER-A)
• Switch
  • Label with el-switch repeating event (#15178 by @FAKER-A)
• Slider
  • Fix style problem when clicking slider bar(#15561 by @luckyCao)
• Radio
  • Fix issue 14808 (#14809 by @OverTree)
• Form
  • Fix resetFields issue (15181 by @luckyCao)
• Chore
  • Upgrade dependencies and fix demo bug (#15324 by ziyoung)
• Type
  • Fix loading type definition (#15635 by @iamkun)
  • Fix Icon type (#15634 by @iamkun)
  • Fix Link type definition (#15402 by @iamkun)

Optimization

• Cascader
  • Refactor (#15611 by @SimonaliaChen)
• Chore
  • Update make new component logic (by @iamkun)
• Docs
  • Rename variable in docs (#15185 by @liupl)
  • Fix image attribute type and default value (#15423 by @haoranyu)
  • Fix form doc bug (#15228 by @SHERlocked93)

新特性

• Backtop
  • 新增 Backtop 组件 (#15541 by @iamkun)
• PageHeader
  • 新增 PageHeader 组件 (#15714 by @ziyoung)
• InfiniteScroll
  • 新增 InfiniteScroll 指令 (#15567 by @iamkun)
• Cascader
  • 新增多选模式和 filter-method 方法 (#15611 by @SimonaliaChen)
• Message
  • 信息依次展示 (#15639 by @island205)
• Tag
  • 新增 effect 属性 (#15725 by @SimonaliaChen)
• Tabs
  • 卡片模式下标题左对齐 (#15695 by @luckyCao)
• DatePicker
  • 支持字符串常量 (#15525 by @island205)
• Image
  • 支持 attrs 和 listeners (#15578 by @VanMess)
• Theme
  • 新增 popup 背景配置 (#15412 by @iamkun)
• Chore
  • 更新文档首页 (#15682 by @iamkun)

Bug 修复

• Table
  • 修复排序条件为空时的排序问题 (#15012 by @joelxr)
• Image
  • 修复 ssr 问题和 object-fit 的兼容性 (#15346 by @SimonaliaChen)
• Input
  • 修复 show-word-count 样式问题 (#15359 by @lvjiaxuan)
  • 修复删除图标样式 (#15354 by @YiiGuxing)
• Calendar
  • 修复星期展示错误 (#15399 by @qingdengyue)
  • 修复十月展示问题 (#15394 by @qingdengyue)
• Tabs
  • 修复 padding 问题 (#15461 by @SimonaliaChen)
• Tag
  • 修复阻止冒泡问题 (#15150 by @infjer)
• Form
  • 修复 form-item 的高度错误 (#15457 by @SimonaliaChen)
  • 修复 resetFields 问题 (15181 by @luckyCao)
• Tooltip
  • 修复自定义 tabindex 不生效问题 (#15619 by @SimonaliaChen)
• Link
  • 修复图标 class 问题 (#15752 by @iamkun)
• Select
  • 回滚清除时，设置 value 为 null 的修改 (#15447 by @iamkun)
• Loading
  • 修复 Dom 不更新的问题 (#15123 by @FAKER-A)
• Switch
  • 修复事件重复触发问题 (#15178 by @FAKER-A)
• Slider
  • 修复点击时样式问题 (#15561 by @luckyCao)
• Radio
  • 修复 value 不更新的问题 (#14809 by @OverTree)
• Form
  • 修复 resetFields 问题 (15181 by @luckyCao)
• Chore
  • 更新依赖 (#15324 by ziyoung)
• Type
  • 修复 Loading 定义文件 (#15635 by @iamkun)
  • 修复 Icon 定义文件 (#15634 by @iamkun)
  • 修复 Link 定义文件 (#15402 by @iamkun)

优化

• Cascader
  • 重构 (#15611 by @SimonaliaChen)
• Chore
  • 更新新建组件的脚本 (by @iamkun)
• Docs
  • 重新命名文档变量 (#15185 by @liupl)
  • 更新 Image 组件文档 (#15423 by @haoranyu)
  • 修复 Form 组件文档错误 (#15228 by @SHERlocked93)