localStorage.on

Adds an event callback for changes in localStorage. Also see localStorage.set().

localStorage.on(eventName, callback);

Input

Variable	Required	Description
`eventName`	yes	The name of the event. Currently, only the `"update"` event is supported.
`callback`	yes	The callback function to trigger when the event occurs. It has the signature function(entry, value, script)where: •entry— the key name that was updated •value— the new value •script — the name of the script that made the change

Output

This function does not return anything.

Limitations

See localStorage.set() for storage limitations.

Comments

Use this function to detect when other scripts perform a localStorage.set() operation.

The "update" event does not trigger for localStorage.set() calls made within the same script.

Examples

To see how localStorage.on("update") works, you’ll need two scripts:

Listener Script:


localStorage.on("update", function(entry, value, script) {
  console.log("localStorage got updated:", entry, "=", value, "by script", script);
  exit();
});

Initiator Script:


localStorage.set("data", "data from 1");
exit();

How to Run:

Launch the Listener script (it will keep running).
Launch the Initiator script (it will run and stop).
Switch back to the Listener script and check its runtime logs — it should show the update event.