LocalStorage Expiry Mechanism
October 28, 2019 | Coding | No Comments

HTML5 LocalStorage is a great tool, but it never expires. To contrast, SessionStorage expires when the browser tab is closed. But what if you want a longer expiry while preserving data if the browser is closed?
Here are two simple functions to add and check a expiry value to your storage object.
// get from LocalStorage (if the value expired it is destroyed) /** * @return {null} */ function LocalStorageGet(key) { let stringValue = window.LocalStorage.getItem(key); if (stringValue !== null) { let value = JSON.parse(stringValue); let expirationDate = new Date(value.expirationDate); if (expirationDate > new Date()) { return value.value } else { window.LocalStorage.removeItem(key); } } return null; } // add into LocalStorage function LocalStorageSet(key, value, expirationInMin = 10) { let expirationDate = new Date(new Date().getTime() + (60000 * expirationInMin)); let newValue = { value: value, expirationDate: expirationDate.toISOString() }; window.LocalStorage.setItem(key, JSON.stringify(newValue)) }JavaScript
By Wayne