适配器模式

定义

将一个类的接口转换为用户需要的另外一个接口，解决类（对象）之间接口不兼容的问题

类图

代码

基本实例1

// 这是需要被适配的类
class Socket {
  output() {
    return "220V";
  }
}
// 转换插头的 类
abstract class Power {
  abstract charge(): string;
}
class PowerAdaptor extends Power {
  constructor(public socket: Socket) {
    super();
  }
  charge(): string {
    return this.socket.output() + "转换为12v";
  }
}
let adaptor = new PowerAdaptor(new Socket());
console.log(adaptor.charge());

axios类应用适配器

使用适配器处理浏览器和服务器端发送请求的统一处理

// 使用适配器模式处理浏览器或者服务端接口请求
let url = require("url");
function axios(config) {
  let adaptor = getDefaultAdaptor();
  // 兼容浏览器和服务器端
  return adaptor(config);
}
function getDefaultAdaptor() {
  let adaptor;
  // 在浏览器端
  if (typeof XMLHttpRequest !== "undefined") {
    adaptor = xhrAxios;
  } else if (typeof process !== "undefined") {
    // 服务器端
    adaptor = httpAxios;
  }
  return adaptor;
}
function xhrAxios(config) {
  return new Promise((resolve, reject) => {
    let XHR = new XMLHttpRequest();
    XHR.open(config.method, config.url, true);
    XHR.onreadystatechange = function () {
      if (XHR.readyState == 4) {
        if (XHR.status == 200) {
          resolve(XHR.responseText);
        } else {
          reject("请求错误");
        }
      }
    };
  });
}
function httpAxios(config) {
  let http = require("http");
  let urlObj = url.parse(config.url);
  return new Promise((resolve, reject) => {
    const options = {
      hostname: urlObj.hostname,
      port: urlObj.port,
      path: urlObj.path,
      method: config.method,
    };
    let req = http.request(options, (response) => {
      let chunks = [];
      response.on("data", function (chunk) {
        chunks.push(chunk);
      });
      response.on("end", function () {
        let result = Buffer.concat(chunks).toString();
        resolve(result);
      });
    });
    req.on("error", function (error) {
      reject(error);
    });
    req.end();
  });
}

多维数组扁平化

let treeData = [
  {
    name: "河南",
    key: "henan",
    children: [
      { name: "郑州", key: "zhengzhou" },
      { name: "开封", key: "kaifeng" },
      { name: "洛阳", key: "luoyang" },
      {
        name: "新乡",
        key: "xinxiang",
        children: [
          { name: "辉县", key: "huixian" },
          { name: "长垣", key: "changyuan" },
          { name: "延津", key: "yanjin" },
        ],
      },
    ],
  },
  {
    name: "山东",
    key: "shandong",
    children: [
      { name: "济南", key: "jinan" },
      { name: "青岛", key: "qingdao" },
    ],
  },
];
// 要把该数组对象放在函数外面，这样每次函数迭代是不会清空数组
let arrData = [];
function flattenData(treeData) {
  treeData.forEach((item) => {
    arrData.push({ name: item.name, key: item.key });
    if (item.children) {
      flattenData(item.children, arrData);
    }
  });
  return arrData;
}
function flattenData2(treeData, arr) {
  treeData.forEach((item) => {
    if (item.children) {
      flattenData2(item.children, arr);
    }
    arr.push({ name: item.name, key: item.key });
  });
}
console.log(flattenData(treeData));
let flattenArr = [];
flattenData2(treeData, flattenArr);
console.log(flattenArr);