// see: https://github.com/DVLP/localStorageDB/blob/master/localStorageDB.js
let db;
const dbName = "_metapageDb";
const storeName = "versions";
const openDbRequest = indexedDB.open(dbName, 1);
openDbRequest.onsuccess = function() { db = openDbRequest.result; console.log("open success"); };
openDbRequest.onerror = function(event) { console.log(event); };
openDbRequest.onupgradeneeded = function() {
console.log("upgrading");
db = null;
var store = openDbRequest.result.createObjectStore(storeName, { keyPath: "k" });
store.transaction.oncomplete = function() {
db = store.transaction.db;
console.log("upgrade complete");
};
};
function getItem(key, callback) {
console.log("get", key);
if (!db) {
setTimeout(function () { getItem(key, callback); }, 100);
return;
}
db.transaction(storeName).objectStore(storeName).get(key).onsuccess = function(event) {
var result = (event.target.result && event.target.result.v) || null;
callback(result);
};
}
const keyValue = {k: "", v: ""};
function setItem(key, value) {
console.log("set", value);
if (!db) {
setTimeout(function () { setItem(key, value); }, 100);
return;
}
keyValue.k = key;
keyValue.v = value;
db.transaction(storeName, 'readwrite').objectStore(storeName).put(keyValue);
}