{
  "schemaVersion": 1,
  "sourceKind": "authored-spec",
  "provenance": "authored-in-repo",
  "specFile": "spec/移动端规格.md",
  "specSection": "2 · 底部标签栏 TabBar",
  "confidence": "high",
  "slug": "tabbar",
  "name": "底部标签栏 TabBar",
  "semanticTypeCandidates": [
    "tabbar",
    "bottom-navigation",
    "tablist"
  ],
  "variantDimensions": [
    {
      "name": "count",
      "values": [
        "2",
        "3",
        "4",
        "5"
      ]
    },
    {
      "name": "badge",
      "values": [
        "none",
        "dot",
        "number"
      ]
    }
  ],
  "representativeVariants": [
    {
      "count": "3",
      "badge": "none",
      "label": "三项基础"
    },
    {
      "count": "4",
      "badge": "number",
      "label": "四项 + 数字角标"
    },
    {
      "count": "5",
      "badge": "dot",
      "label": "五项 + 红点"
    },
    {
      "count": "4",
      "badge": "dot",
      "label": "含禁用项"
    }
  ],
  "anatomy": {
    "bar": "标签栏容器，固定于页面底部，高度 50px + 底部安全区",
    "item": "单个标签，含图标与文字",
    "icon": "图标，可为内联 SVG",
    "label": "标签文字，11px",
    "badge": "角标，可为数字或红点"
  },
  "structurePatterns": {
    "count": "2 / 3 / 4 / 5（标签数量，超过 5 项应改用其它导航形态）",
    "badge": "none / dot / number"
  },
  "usageHints": [
    "底部主导航，2~5 个标签页之间切换，是移动端一级导航",
    "固定于页面底部，高度 50px + 底部安全区",
    "每项点击热区等分整栏宽度，高度不小于 44px",
    "选中项切换后 aria-selected 同步变化",
    "底部内边距包含安全区",
    "标签文字 11px，图标可为内联 SVG"
  ],
  "doNotInvent": [
    "标签项超过 5 个时的滚动或折叠规则",
    "图标资源的成套规则（规格只约定尺寸与语义）"
  ],
  "unknowns": [
    "角标超过两位数的收敛（如 99+）",
    "选中态是否带图标填充切换"
  ],
  "interaction": [
    "每项点击热区等分整栏宽度，高度不小于 44px",
    "选中项切换后 aria-selected 同步变化",
    "底部内边距包含安全区"
  ],
  "accessibility": [
    "容器 role=tablist，单项 role=tab",
    "选中项 aria-selected=true，未选中 false",
    "每项具备 aria-label（图标 + 文字时可用文字代替）"
  ],
  "api": {
    "source": "implementation",
    "note": "props / events / slots 为 6 端实现的公共接口（说明文字取自规格对应小节）。字段名与各端源码逐名核对：node tools/verify-mobile-docs.mjs",
    "props": [
      {
        "name": "items",
        "type": "Item[]",
        "default": "[]",
        "desc": "标签项：{ key, label, icon?, badge?, dot?, disabled?, ariaLabel? }（规格 §2.2）",
        "required": false
      },
      {
        "name": "value",
        "type": "string",
        "default": "''",
        "desc": "当前选中项的 key（受控，规格 §2.4）",
        "required": false
      },
      {
        "name": "label",
        "type": "string",
        "default": "'主导航'",
        "desc": "整栏的无障碍名称（role=tablist 的 aria-label，规格 §2.6）",
        "required": false
      }
    ],
    "events": [
      {
        "name": "change",
        "params": "key: string",
        "desc": "切换标签时触发，参数为选中项的 key"
      }
    ],
    "slots": [
      {
        "name": "—",
        "desc": "无插槽；项由 items 驱动（uni-app 端的图标由宿主以图片/slot 提供，规格 §2.7）"
      }
    ],
    "requiredNote": "「必传」按严格定义：实现里**没有默认值**时才为 Y（本门禁逐条核对 props 与各端源码的默认值，防止契约与实现脱节）。"
  },
  "variantClasses": {
    "count": {
      "2": [
        "(.kole-m-tabbar__item)"
      ],
      "3": [
        "(.kole-m-tabbar__item)"
      ],
      "4": [
        "(.kole-m-tabbar__item)"
      ],
      "5": [
        "(.kole-m-tabbar__item)"
      ]
    },
    "badge": {
      "none": [],
      "dot": [
        ".kole-m-tabbar__badge",
        ".is-dot"
      ],
      "number": [
        ".kole-m-tabbar__badge"
      ]
    }
  },
  "demos": [
    {
      "id": "count-3",
      "group": "01 组件类型",
      "title": "三项",
      "desc": "最常见的三项导航：图标 + 文字等分整栏宽度，热区高度 ≥ 44px。",
      "variant": "count=3"
    },
    {
      "id": "count-4-badge",
      "group": "01 组件类型",
      "title": "四项 + 数字角标",
      "desc": "角标宽度随位数增长；超过两位数按业务约定收敛（如 99+）。",
      "variant": "count=4 / badge=number"
    },
    {
      "id": "count-5-dot",
      "group": "01 组件类型",
      "title": "五项 + 红点",
      "desc": "五项是上限，标签文字仍不换行；红点用于「有更新但不必计数」。",
      "variant": "count=5 / badge=dot"
    },
    {
      "id": "disabled",
      "group": "02 组件状态",
      "title": "含禁用项",
      "desc": "禁用项置灰、保留位置、不参与切换（无权限模块的常见表达）。",
      "variant": "disabled"
    }
  ],
  "related": [
    {
      "slug": "navbar",
      "why": "顶栏给标题与返回，标签栏给主模块切换；两者一起构成一级框架"
    },
    {
      "slug": "pullrefresh",
      "why": "都在页面上做纵向处理，注意手势与底部导航栏不要抢事件"
    }
  ]
}