feat: add country/region select (#207)

Signed-off-by: sh1luo <690898835@qq.com>

web/src/SelectRegionBox.js

@@ -0,0 +1,61 @@
+// Copyright 2021 The casbin Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import React from "react";
+import * as Setting from "./Setting";
+import { Select } from "antd";
+
+const { Option } = Select;
+
+class SelectRegionBox extends React.Component {
+    constructor(props) {
+        super(props);
+        this.state = {
+            classes: props,
+            value: "",
+        };
+    }
+
+    onChange(e) {
+        this.props.onChange(e);
+        this.setState({value: e})
+    };
+
+    render() {
+        return (
+          <Select virtual={false}
+                  showSearch
+                  optionFilterProp="label"
+                  style={{width: '100%'}}
+                  defaultValue={this.props.defaultValue || undefined}
+                  placeholder="Please select country/region"
+                  onChange={(value => {this.onChange(value);})}
+                  filterOption={(input, option) =>
+                      option.label.indexOf(input) >= 0
+                  }
+          >
+            {
+                Setting.CountryRegionData.map((item, index) => (
+                    <Option key={index} value={item.name} label={item.name} >
+                        <img src={`${Setting.StaticBaseUrl}/flag-icons/${item.code}.svg`} alt={item.name} height={20} />{" "}
+                        {item.name}
+                    </Option>
+                ))
+            }
+          </Select>
+        )
+    };
+}
+
+export default SelectRegionBox;