我有一个 indexedDB，我试图用它来捕获有关用户注册的表单信息。该部分工作正常，但教授希望使用创建时设置的用户名和密码创建一次帐户，以便他可以登录。
我解决这个问题的方法是使用 localStorage API。我创建了一个函数来检查是否曾经创建过管理员帐户，如果没有创建它，则调用 addAdmin() 函数。
我试图通过复制我的 addObject() 来创建 addAdmin() 但由于某种原因，我的 db 变量在控制台中返回为未定义。
错误”未捕获的类型错误：无法调用未定义的方法“事务”
var mainForm, fName, lName, uName, pass, email, dob, phone, bio, nl, terms, school, gender, save, reset, db;
//-------------USER DB------------------//
function startDB(){
mainForm = document.getElementById('mainFormSidebar');
fname = document.getElementById('fName');
lName = document.getElementById('lName');
users = document.getElementById('uName');
pass = document.getElementById('password');
email = document.getElementById('email');
dob = document.getElementById('dob');
phone = document.getElementById('phone');
bio = document.getElementById('bio');
nl = document.getElementById('newsletter');
terms = document.getElementById('terms');
school = document.getElementById('school');
gender = document.getElementsByName('gender');
save = document.getElementById('save');
reset = document.getElementById('reset');
reset.addEventListener('click',clearForm);
databox = document.getElementById('databox');
mainForm.addEventListener('submit',addObject);
//open DB
var request = indexedDB.open('macroPlay');
//if fails
request.addEventListener('error', showerror);
//if succeeds
request.addEventListener('success', start);
//if !exist, create.
request.addEventListener('upgradeneeded', createdb);
//Create Admin account on launch
chkAdmin();
}
function createdb(e){
var datababase = e.target.result;
var myusers = datababase.createObjectStore('users', {keyPath: 'userName'});
}
function start(e){
db = e.target.result;
showUsers();// Show all values in the object store
}
function addObject(){
if(confirm('Are you sure you want to resgister?')){
var fName = document.getElementById('fName').value;
var lName = document.getElementById('lName').value;
var userName = document.getElementById('uName').value;
var pass = document.getElementById('password').value;
var email = document.getElementById('email').value;
var dob = document.getElementById('dob').value;
var phone = document.getElementById('phone').value;
var bio = document.getElementById('bio').value;
var nl = document.getElementById('nl').value;
var terms = document.getElementById('terms').value;
var school = document.getElementById('school').value;
//May need to set a loop to find value of radio
var gender;
var radios = document.getElementsByName('gender');
for (var i = 0, length = radios.length; i < length; i++) {
if (radios[i].checked) {
gender=radios[i].value;
}
}
//set up transaction
var mytransaction = db.transaction(['users'], "readwrite");
//get object store
var myusers = mytransaction.objectStore('users');
//Add item
var request = myusers.add(new getUser(userName,fName,lName,pass,email,dob,phone,bio,nl,terms,school,gender));
}
// Show all results.
mytransaction.addEventListener('complete', showUsers);
//Reset Form Fields
resetForm();
}
function getUser(userName, fn, ln, pw, em, dob, tel, bio, nl,tm, scl, gender){
this.userName = userName;
this.fn = fn;
this.ln = ln;
this.pw = pw;
this.em = em;
this.dob = dob;
this.tel = tel;
this.bio = bio;
this.nl = nl;
this.tm = tm;
this.scl = scl;
this.gender = gender;
}
//------Create Admin Account-----//
function chkAdmin(){
alert('before adding admin');
if(localStorage.getItem('admin')!="added"){
alert('adding admin');
addAdmin();
alert('admin added');
}
}
function addAdmin(){
//set up transaction
var mytransaction = db.transaction(['users'], "readwrite");
//get object store
var myusers = mytransaction.objectStore('users');
var request = myusers.add(new getUser('admin','Shawn','Smith-Choa','admin'));
request.addEventListener('success',showUsers);
//Locally store that admin as been created
var admin = 'admin';
var value = 'added';
newItem(admin,value);
}
//-------------Web Storage API------------//
function newItem(id,style){
localStorage.setItem(id,style);
}