class myStorage {
constructor(version = 1, prefix = "") {
this.version = version;
this.prefix = prefix;
}
// Greasemonkey storage API
read(key, defaultValue) {
const raw = GM_getValue(this._prefix(key), defaultValue);
// let str = (this.compress) ? LZString.decompressFromUTF16(raw) : raw;
return this._parse(raw);
}
write(key, value) {
const raw = this._stringify(value);
// let str = (this.compress) ? LZString.compressToUTF16(raw) : raw;
return GM_setValue(this._prefix(key), raw);
}
delete(key) {
return GM_deleteValue(this._prefix(key));
}
readKeys() {
return GM_listValues();
}
// browser localstorage
// read(key, defaultValue) {
//     const raw = localStorage.getItem(this._prefix(key), defaultValue);
//     const val = raw || defaultValue;
//     // const str = (this.compress) ? LZString.decompressFromUTF16(val) : val;
//     // return this._parse(str);
//     return this._parse(val);
// }
// write(key, value) {
//     const raw = this._stringify(value);
//     // let str = (this.compress) ? LZString.compressToUTF16(raw) : raw;
//     localStorage.setItem(this._prefix(key), raw);
//     return;
// }
// delete(key) {
//     return localStorage.removeItem(this._prefix(key));
// }
// readKeys() {
//     let keys = [];
//     for(let i=0, l=localStorage.length; i < l; i++){
//        keys.push( localStorage.getItem(localStorage.key(i)) );
//     }
//     return keys;
// }
// “Set” means “add if absent, replace if present.”
set(key, value) {
let savedVal = this.read(key);
if (typeof savedVal === 'undefined' || !savedVal) {
// add if absent
return this.add(key, value);
} else {
// replace if present
this.write(key, value);
return true;
}
}
// “Add” means “add if absent, do nothing if present” (if a uniquing collection).
add(key, value) {
let savedVal = this.read(key, false);
if (typeof savedVal === 'undefined' || !savedVal) {
this.write(key, value);
return true;
} else {
if (this._isArray(savedVal)) { // is array
let index = savedVal.indexOf(value);
if (index !== -1) {
// do nothing if present
return false;
} else {
// add if absent
savedVal.push(value);
this.write(key, savedVal);
return true;
}
} else if (this._isObject(savedVal)) { // is object
// merge obj value on obj
let r###lt, objToMerge = value;
r###lt = Object.assign(savedVal, objToMerge);
this.write(key, r###lt);
return false;
}
return false;
}
}
// “Replace” means “replace if present, do nothing if absent.”
replace(key, itemFind, itemReplacement) {
let savedVal = this.read(key, false);
if (typeof savedVal === 'undefined' || !savedVal) {
// do nothing if absent
return false;
} else {
if (this._isArray(savedVal)) { // is Array
let index = savedVal.indexOf(itemFind);
if (index !== -1) {
// replace if present
savedVal[index] = itemReplacement;
this.write(key, savedVal);
return true;
} else {
// do nothing if absent
return false;
}
} else if (this._isObject(savedVal)) {
// is Object
// replace property's value
savedVal[itemFind] = itemReplacement;
this.write(key, savedVal);
return true;
}
return false;
}
}
// “Remove” means “remove if present, do nothing if absent.”
remove(key, value) {
if (typeof value === 'undefined') { // remove key
this.delete(key);
return true;
} else { // value present
let savedVal = this.read(key);
if (typeof savedVal === 'undefined' || !savedVal) {
return true;
} else {
if (this._isArray(savedVal)) { // is Array
let index = savedVal.indexOf(value);
if (index !== -1) {
// remove if present
savedVal.splice(index, 1);
this.write(key, savedVal);
return true;
} else {
// do nothing if absent
return false;
}
} else if (this._isObject(savedVal)) { // is Object
let property = value;
delete savedVal[property];
this.write(key, savedVal);
return true;
}
return false;
}
}
}
get(key, defaultValue) {
return this.read(key, defaultValue);
}
getAll() {
const keys = this._listKeys();
let obj = {};
for (let i = 0, len = keys.length; i < len; i++) {
obj[keys[i]] = this.read(keys[i]);
}
return obj;
}
getKeys() {
return this._listKeys();
}
getPrefix() {
return this.prefix;
}
empty() {
const keys = this._listKeys();
for (let i = 0, len = keys.lenght; i < len; i++) {
this.delete(keys[i]);
}
}
has(key) {
return this.get(key) !== null;
}
forEach(callbackFunc) {
const allContent = this.getAll();
for (let prop in allContent) {
callbackFunc(prop, allContent[prop]);
}
}
_parse(value) {
if (this._isJson(value)) {
return JSON.parse(value);
}
return value;
}
_stringify(value) {
if (this._isJson(value)) {
return value;
}
return JSON.stringify(value);
}
_listKeys(usePrefix = false) {
const prefixed = this.readKeys();
let unprefixed = [];
if (usePrefix) {
return prefixed;
} else {
for (let i = 0, len = prefixed.length; i < len; i++) {
unprefixed[i] = this._unprefix(prefixed[i]);
}
return unprefixed;
}
}
_prefix(key) {
return this.prefix + key;
}
_unprefix(key) {
return key.substring(this.prefix.length);
}
_isJson(item) {
try {
JSON.parse(item);
} catch (e) {
return false;
}
return true;
}
_isObject(a) {
return (!!a) && (a.constructor === Object);
}
_isArray(a) {
return (!!a) && (a.constructor === Array);
}
}