In indexedDB in html5 api, I can use it to store key-value pairs. But how can I make sure that after adding a certain key-value, after 1 day, that key should automatically be deleted from the db.
I was thinking of wrapping the value in an object with current datetime, and expiry time, and when u get the value, check the time difference, but is this the best way?
Thanks
Yep, what Scott Marcus and dgrogan said. One more hint: if you create an index on the timestamp, you can iterate a cursor over the range of "expired" values and delete them after opening the database.
const open = indexedDB.open("demo");
open.onupgradeneeded = function () {
const db = open.result;
const store = db.createObjectStore("store");
const index = store.createIndex("timestamp", "timestamp");
// Populate with some dummy data, with about half from the past:
for (let id = 0; id < 20; ++id) {
store.put(
{
value: Math.random(),
timestamp: new Date(Date.now() + (Math.random() - 0.5) * 10000),
},
id
);
}
};
open.onsuccess = function () {
const db = open.result;
const tx = db.transaction("store", "readwrite");
// Anything in the past:
const range = IDBKeyRange.upperBound(new Date());
tx
.objectStore("store")
.index("timestamp")
.openCursor(range).onsuccess = function (e) {
const cursor = e.target.result;
if (!cursor) return;
console.log("deleting: " + cursor.key);
cursor.delete();
cursor.continue();
};
// This transaction will run after the first commits since
// it has overlapping scope:
const tx2 = db.transaction("store");
tx2.objectStore("store").count().onsuccess = function (e) {
console.log("records remaining: " + e.target.result);
};
};
Support for automatically expiring IndexedDB and other storage data is being considered. See https://github.com/whatwg/storage/issues/11. It would be helpful if you could describe your use case there.
In the meantime you'll have to do something like you outlined or what Scott Marcus suggests.
IndexedDB can only be modified by code. It has no automatic capabilities. Why not just store the data with a timestamp value and modify your code to remove it when the timestamp is out of date?
