【Angular2】基于localStorage实现本地备份操作记录

引言

项目中需要对用户的操作记录备份起来，如果后端出现任何问题，可以从前端把用户操作记录提取出来，然后后期把数据导入到数据库

功能

网络监测

1.监测每条记录的提交情况，分辨出是客户端和服务器问题；

2.呼吸灯动态显示当前整体提交状况；

3.监控中心可以查看每条记录的提交情况；

4.监控中心可以控制对每条记录的监控状态；

5.监控中心可以切换网络监测的开闭模式；

智能提交

1.监控中心每隔10秒监测一次提交情况，如果发现有没有提交成功的内容，会在监听到有提交成功的时刻，自动提交所有没有提交成功的记录；

2.监控中心可以切换智能提交的开闭模式；

自动备份

1.监控中心会在最后的时刻将所有用户的操作记录下载到本地；

2.监控中心可以切换自动备份的开闭模式；

设计思路

1.首先各个题型组件在调取服务之后，通过服务返回的值来判断提交情况，并记录操作，如果有问题则为服务端故障，同时更新网络状态；

2.如果调取服务出现任何异常导致无法获取返回值，则为客户端问题，记录操作并标记，同时更新网络状态；

3.呼吸灯实时监测网络状态，累计3次故障后客户端报警；

4..进入监控中心，读取所有操作记录及其标记，显示提交情况，同时根据具体情况选择性的关闭对应的记录的监测（否则会一直报警）；

5.在操作的过程中，如果发现有没有提交成功的操作，同时监测到最近有提交成功，那么就把之前没有提交成功的操作重新自动提交；

6..监控中心如果出现很多问题或者关键性问题，可以开启备份操作下载功能，用户操作完成之后会把操作自动下载到本地；

代码说明

各题目组件 ts

/* 向后台提交学生答案 */
public updateStudentAnswerToBackend(answer: Answer) {
let url: string = "examinationEvaluation-web/onlineExam/updatePaperRecordByRecord" + this.authGuardService.getTicket();
let body: string = JSON.stringify(answer);
this.exampapaerservice.post(url, body).subscribe(
res => {
if (res.json().code == "1111" || res.json().data != true) {
this.backupAnswer(answer, 1); //备份答案
} else {
this.backupAnswer(answer, 0); //备份答案
}
}
);
console.log("学生提交答案-radio");
}
/* 备份用户答案 */
private backupAnswer(answer: Answer, status: number) {
//备份答案记录
console.log("answer-backup-log---"+ExamPaperService.userOperationAmount);
ExamPaperService.userOperationAmount++; //操作序号递增
localStorage.setItem("userOperationAmount", ExamPaperService.userOperationAmount.toString()); //记录操作序号
localStorage.setItem(answer.studentId + ExamPaperService.userOperationAmount, JSON.stringify(answer) + status); //记录操作内容
//记录提交情况
let flag: boolean = true;
let ns: string[] = JSON.parse(localStorage.getItem("NetWorkState"));
for (var i = 0; i < ns.length; i++) {
if (answer.questionMainId == ns[i]) { flag = false; }
}
if (status != 0 && flag) {
ns[0] = (parseInt(ns[0]) + 1).toString();
localStorage.setItem("NetWorkState",JSON.stringify(ns));
}
}

公共服务 ts

/* 处理失败提交 */
public handleUpdateAnswerError(error: Response) {
//保存用户答案到localStorage
let answer: Answer = <Answer>(JSON.parse(ExamPaperService.studentAnswer));
this.backupAnswer(answer, 2);
return Observable.throw(error.json().error || '网络问题：server error');
}
/* 备份用户答案 */
private backupAnswer(answer: Answer, status: number) {
//备份答案记录
console.log("answer-backup-log---" + ExamPaperService.userOperationAmount);
ExamPaperService.userOperationAmount++; //操作序号递增
localStorage.setItem("userOperationAmount", ExamPaperService.userOperationAmount.toString()); //记录操作序号
localStorage.setItem(answer.studentId + ExamPaperService.userOperationAmount, JSON.stringify(answer) + status); //记录操作内容
//记录提交情况
let flag: boolean = true;
let ns: string[] = JSON.parse(localStorage.getItem("NetWorkState"));
for (var i = 0; i < ns.length; i++) {
if (answer.questionMainId == ns[i]) { flag = false; }
}
if (status != 0 && flag) {
ns[0] = (parseInt(ns[0]) + 1).toString();
localStorage.setItem("NetWorkState", JSON.stringify(ns));
}
}

监控中心 ts

ngOnInit() {
//获得当前操作数量
this.getUserOperationAmount();
//初始化网络状态
let networkList: string[] = [];
networkList.push("0");
localStorage.setItem("NetWorkState", JSON.stringify(networkList));
//初始化备份模式
localStorage.setItem("NetWorkBackupPattern", "0");
//开始监测
this.startMonitorNetworkStatus();
}
/* 开始监测网络状态 */
startMonitorNetworkStatus() {
this.timer = setInterval(() => {
this.networkState = parseInt(JSON.parse(localStorage.getItem("NetWorkState"))[0]);
let el: Element = document.getElementById("networkstate");
if (this.networkState == 1) {
el.setAttribute("class", "breathe-yellow-btn");
} else if (this.networkState == 3) {
el.setAttribute("class", "breathe-red-btn");
} else if (this.networkState > 3) {
this.display_error = true;
let ns: string[] = JSON.parse(localStorage.getItem("NetWorkState"));
ns[0] = "3";
localStorage.setItem("NetWorkState", JSON.stringify(ns));
}
}, 1000);
}
/* 刷新状态 */
refreshStatus() {
this.getAnswerStatus();
this.getMonitorStatus();
}
/* 清除缓存 */
clearLocalStorage() {
localStorage.clear();
}
/* 获得题目提交状态 */
getAnswerStatus() {
console.log("Start-getAnswerStatus-------");
for (var i = 0; i < parseInt(localStorage.getItem("userOperationAmount")); i++) {
let answerLog: string = localStorage.getItem(localStorage.getItem("userId") + i);
let answerStatus = answerLog.substring(answerLog.length - 1);
let answer: Answer = JSON.parse(answerLog.substring(0, answerLog.length - 1));
if (answerStatus == "0") {
let el = document.getElementById("network" + answer.questionMainId);
if (el != null) {
el.setAttribute("class", "badge badge-success badge_postion");
el.innerHTML = "成功提交";
}
}
if (answerStatus == "1") {
let el = document.getElementById("network" + answer.questionMainId);
if (el != null) {
el.setAttribute("class", "badge badge-warning badge_postion");
el.innerHTML = "客户端故障";
}
}
if (answerStatus == "2") {
let el = document.getElementById("network" + answer.questionMainId);
if (el != null) {
el.setAttribute("class", "badge badge-important badge_postion");
el.innerHTML = "服务器故障";
}
}
}
}
/* 获得检测状态 */
getMonitorStatus() {
console.log("Start-getMonitorStatus-------");
let idList: string[] = JSON.parse(localStorage.getItem("NetWorkState"));
for (var i = 1; i < idList.length; i++) {
let el = document.getElementById("monitor" + idList[i]);
if (el != null) {
el.setAttribute("class", "btn btn-danger btn-xs pull-right");
el.innerHTML = "监测已停止";
}
}
}
/* 获得操作记录数量 */
getUserOperationAmount() {
let amount: number = 1;
while (localStorage.getItem("userId" + amount)!=null) {
amount++;
}
localStorage.setItem("userOperationAmount",(amount-1).toString());
}
/* 切换监测状态 */
changeMonitorStatus(monitorId: string) {
console.log("Start-changeMonitorStatus-------");
let exitFlag: boolean = true;
let questionId = monitorId.substring(7, monitorId.length);
let idList: string[] = JSON.parse(localStorage.getItem("NetWorkState"));
for (var i = 0; i < idList.length; i++) {
if (questionId == idList[i]) {
//切换为开始
let el = document.getElementById("monitor" + idList[i]);
if (el != null) {
el.setAttribute("class", "btn btn-primary btn-xs pull-right");
el.innerHTML = "正在监测中";
}
idList.splice(i, 1);
localStorage.setItem("NetWorkState", JSON.stringify(idList));
exitFlag = false;
}
}
//切换为停止
if (exitFlag) {
let el = document.getElementById(monitorId);
if (el != null) {
el.setAttribute("class", "btn btn-danger btn-xs pull-right");
el.innerHTML = "监测已停止";
}
idList.push(questionId);
localStorage.setItem("NetWorkState", JSON.stringify(idList));
}
}
private backupPatternStatus: boolean = false; //备份模式状态
/* 切换备份模式 */
changeBackupPattern() {
if (this.backupPatternStatus) {
//切换为不备份
let el = document.getElementById("networkbackuppattern");
if (el != null) {
el.setAttribute("class", "btn btn-info pull-left");
el.innerHTML = "非备份模式";
localStorage.setItem("NetWorkBackupPattern", "0");
this.backupPatternStatus = false;
}
} else {
//切换为开始备份
let el = document.getElementById("networkbackuppattern");
if (el != null) {
el.setAttribute("class", "btn btn-warning pull-left");
el.innerHTML = "备份模式中";
localStorage.setItem("NetWorkBackupPattern", "1");
this.backupPatternStatus = true;
}
}
}
/* --------------------------------------------------------- */
private openNum: number = 0;//点击三次可以打开
/* 打开模态框 */
openModal(modal: HTMLElement) {
this.openNum++;
if (this.openNum > 2) {
this.refreshStatus();
modal.style.visibility = 'visible';
this.openNum = 0;
}
}
/* 关闭模态框 */
close(modal: HTMLElement) {
modal.style.visibility = 'hidden';
}
/* 拖动模态框 */
draggable() {
$('.modal-dialog').draggable();
}

本地备份下载 ts

/* 创建备份文本并下载 */
createBackupText() {
let userLog: string = "";
for (var i = 0; i < parseInt(localStorage.getItem("userOperationAmount")); i++){
userLog = userLog +localStorage.getItem(localStorage.getItem("userId")+i);
}
let data = new Blob([userLog], { type: 'application/json' })
var link = document.createElement("a");
link.setAttribute("href", window.URL.createObjectURL(data));
link.setAttribute("download", localStorage.getItem("userId") + '.json');
link.style.visibility = 'hidden';
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
console.log("------ Start Create File And Download --------");
}

小结

要针对不同的业务场景采取不同的解决方案，尽可能考虑全面