关于xml:封装x2jsPromise实现JSON转XML格式

个别服务端接口的参数都是 json 格局，然而因为某些起因当入参须要 XML 格局的怎么办? 如装置在本地零碎的 ic 卡驱动服务须要写卡操作的接口入参为 xml 格局：

现有参数，data 项能够有多个：

    var json = {
      iccard: {
        operation: "writeCard",
        data:[{Id:1, Number:10001},...]
      }
    };

理论 XML 格局：

<iccard>
<operation>writeCard</operation>// 接口操作标识 writeCard 为写卡。<data>
<Id>1</Id>
<Number>10001</Number>
</data>

<data>
<Id>2</Id>
<Number>10002</Number>
</data>

<data>
<Id>3</Id>
<Number>10003</Number>
</data>
...
</iccard>

一种形式是把 json 数据通过正则把参数全都转成有闭合标签尖括号 <xxx> 的字符串。其实是能够应用一个更简便、稳固的办法，应用 x2js 库把 json 转成 xml 格局，下载安装 x2js 库并导入：

import x2js from "x2js";
var x2jsxml = new x2js();
  if(iccardApi=="writeCard"){
    var json = {
      iccard: {
        operation: "writeCard",
        data: data.param
      }
    };
    data.param = x2jsxml.js2xml(json);// 转成 xml 格局
  }

在申请之前对入参进行解决后把 data 带到入参中，应用 Promise 和 Ajax 封装一个专门解决 ic 卡 XML 接口对接的 CCardAjax 函数
ICCard.js：

"use strict";
import {Loading} from "element-ui";
import x2js from "x2js";
var x2jsxml = new x2js();
const baseUrl = "http://localhost:8888/iccard"; //ic 卡控件地址
let ICCardObj = {};

//iccardApi(read 读卡，writeCard 写卡)
ICCardObj.ajax = (iccardApi, data, that) => {
  var isHideErrorTip = false;
  if ("isHideErrorTip" in data) { // 是否不显示未插卡提醒
    isHideErrorTip = data.isHideErrorTip;
    delete data.isHideErrorTip;
  }
  if(iccardApi=="writeCard"){
    var json = {
      iccard: {
        operation: "writeCard",
        data: data.param
      }
    };
 
    data.param = x2jsxml.js2xml(json);

  }
  var loading = Loading.service({
    lock: true,
    text: "正在执行操作...",
    spinner: "el-icon-loading",
    background: "rgba(0, 0, 0, 0.3)"
  });
  return new Promise((resolve, reject) => {
    $.ajax({
      url: baseUrl + "/" + iccardApi,
      type: "GET",
      data: data,
      success: function(res) {loading.close();
        if (res.resultCode == "error") { // 未插卡 读卡失败
          reject(res);
          if (!isHideErrorTip) {
            that.$message({
              title: "正告",
              message: "请插卡！",
              type: "error"
            });
          }
        } else {resolve(res.dataList);
          console.log("读取胜利");
        }
      },
      error: function(res) {// 读卡失败
        loading.close();
        if (!isHideErrorTip) {
          that.$message({
            title: "正告",
            message: "未启动 IC 卡控件，请先正确启动",
            type: "error"
          });
        }

        reject(res);
      }
    });
  });
};

export default ICCardObj;

把 ICCardAjax 绑定到 vue 原型链上供各组件应用：

import ICCardAjax from "@/assets/js/ICCard.js";
Vue.prototype.ICCardAjax = ICCardAjax;

组件中应用：

    // 读卡 - 查问
    readICCard() {return new Promise((resolve, rej) => {this.ICCardAjax.ajax("read", {}, this)
          .then(res => {resolve(res);
            // 读卡胜利
            ...
          })
          .catch(res => {rej(res);
            ...
         // 读卡失败
          });
      });
    },

   writeCard(data) {return new Promise((resolve, rej) => {this.ICCardAjax.ajax("writeCard", { param: data}, this)
          .then(res => {resolve(res);
            console.log("写卡胜利");
          })
          .catch(res => {rej(res);
            this.$message({
              message: "写卡失败",
              type: "error"
            });
          });
      });
    },

    // 写个卡
    querySubmit() {
     this.writeCard([
                {
                  Id: 4,
                  Number: 111
                },
                 { 
                  Id: 4,
                  Number:222
                },
                 { 
                  Id: 4,
                  Number: 333
                }
                  ]).then(res => {
                this.$message({
                  message: "写查询卡胜利！",
                  type: "success"
                });
                this.readICCard();});
    },

```