export default function ( scheme = '', storage = window.localStorage, encode = JSON.stringify, decode = JSON.parse, dispatch = function (key) { window.dispatchEvent(new StorageEvent('storage', { key: key })); } ) { const prefix = `${scheme}:`; return { getValue: function (path) { let value = storage.getItem(`${prefix}${path}`); if (typeof value !== 'string') { value = '""'; } try { value = decode(value); } catch (e) { value = ''; } return value; }, setValue: function (path, value) { if (value === null) { return this.removeValue(path); } try { value = encode(value); } catch (e) { value = '""'; } const res = storage.setItem(`${prefix}${path}`, value); dispatch(`${prefix}${path}`); return res; }, removeValue: function (path) { const res = storage.removeItem(`${prefix}${path}`); dispatch(`${prefix}${path}`); return res; }, all: function () { return Object.keys(storage).reduce((prev, item, i, arr) => { if (item.indexOf(`${prefix}`) === 0) { const key = item.substr(prefix.length); prev[key] = this.getValue(key); } return prev; }, {}); }, }; }