From c3d9cbfb1e6051f3688472d509ed78c2e653641e Mon Sep 17 00:00:00 2001
From: neverland <jait.chen@foxmail.com>
Date: Wed, 25 Jan 2023 22:39:27 +0800
Subject: [PATCH] feat(Cascader): add useCascaderAreaData method (#11518)

---
 packages/vant-area-data/README.md    | 16 ++++++--
 packages/vant-area-data/package.json |  1 +
 packages/vant-area-data/src/index.ts | 56 +++++++++++++++++++++++++++-
 3 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/packages/vant-area-data/README.md b/packages/vant-area-data/README.md
index 60e57bdf7..2077240fb 100644
--- a/packages/vant-area-data/README.md
+++ b/packages/vant-area-data/README.md
@@ -1,6 +1,6 @@
-# Vant Area Data
+# Vant China Area Data
 
-中国省市区数据，适用于 Vant Area 组件。
+中国省市区数据，适用于 Vant 的 Area 和 Cascader 等组件。
 
 ## 安装
 
@@ -17,10 +17,20 @@ pnpm add @vant/area-data
 
 ## 使用
 
+在 Vant 的 Area 组件中使用时，直接引用 `areaList` 对象即可：
+
 ```ts
 import { areaList } from '@vant/area-data';
 ```
 
+在 Vant 的 Cascader 组件中使用时，请使用 `useCascaderAreaData` 方法：
+
+```ts
+import { useCascaderAreaData } from '@vant/area-data';
+
+const cascaderAreaData = useCascaderAreaData();
+```
+
 ## 数据更新
 
-中国的行政区划每年都会有变动，如果发现省市区数据未及时更新，欢迎提 Pull Request 帮助我们更新。
+中国的行政区划每年都会有变动，如果发现省市区数据未及时更新，欢迎提 Pull Request 帮助我们更新。你可以在[「国家统计局 - 全国区划代码」](http://www.stats.gov.cn/tjsj/tjbz/tjyqhdmhcxhfdm/) 和[「民政部 - 行政区划代码」](https://www.mca.gov.cn/article/sj/xzqh/1980/)上查询到最新数据，请根据官方数据进行核实。
diff --git a/packages/vant-area-data/package.json b/packages/vant-area-data/package.json
index 4a1b76490..ea79164a6 100644
--- a/packages/vant-area-data/package.json
+++ b/packages/vant-area-data/package.json
@@ -11,6 +11,7 @@
       "require": "./dist/index.cjs.js"
     }
   },
+  "sideEffects": false,
   "files": [
     "dist"
   ],
diff --git a/packages/vant-area-data/src/index.ts b/packages/vant-area-data/src/index.ts
index 4b4c5a895..5df0c20f8 100644
--- a/packages/vant-area-data/src/index.ts
+++ b/packages/vant-area-data/src/index.ts
@@ -1,4 +1,8 @@
-export const areaList = {
+export const areaList: {
+  province_list: Record<string, string>;
+  city_list: Record<string, string>;
+  county_list: Record<string, string>;
+} = {
   province_list: {
     110000: '北京市',
     120000: '天津市',
@@ -3886,3 +3890,53 @@ export const areaList = {
     820204: '圣方济各堂区',
   },
 };
+
+type CascaderOption = {
+  text: string;
+  value: string;
+  children?: CascaderOption[];
+};
+
+const makeOption = (
+  text: string,
+  value: string,
+  children?: CascaderOption[]
+): CascaderOption => ({
+  text,
+  value,
+  children,
+});
+
+export function useCascaderAreaData() {
+  const {
+    city_list: city,
+    county_list: county,
+    province_list: province,
+  } = areaList;
+
+  const provinceMap = new Map<string, CascaderOption>();
+  Object.keys(province).forEach((code) => {
+    provinceMap.set(code.slice(0, 2), makeOption(province[code], code, []));
+  });
+
+  const cityMap = new Map<string, CascaderOption>();
+
+  Object.keys(city).forEach((code) => {
+    const option = makeOption(city[code], code, []);
+    cityMap.set(code.slice(0, 4), option);
+
+    const province = provinceMap.get(code.slice(0, 2));
+    if (province) {
+      province.children!.push(option);
+    }
+  });
+
+  Object.keys(county).forEach((code) => {
+    const city = cityMap.get(code.slice(0, 4));
+    if (city) {
+      city.children!.push(makeOption(county[code], code));
+    }
+  });
+
+  return Array.from(provinceMap.values());
+}