javascript - How Can I Reliably Complete Asynchronous Operations on Firefox browser close? -

i'm writing browser extension firefox uses indexeddb save local data. when browser closes, i'd write latest data out indexeddb. however, indexeddb entirely asynchronous, , appears firefox closes before asynchronous writes complete. (i can see database file being created , journaling file getting discarded when browser closes.) there way reliably complete asynchronous operations when firefox closing?

you use eventlistener (you may have write database) listen window close event , preventdefault until finish storing things , close window on callback.

window.addeventlistener("close", function(e) {     e.preventdefault();      //save things     //call window.close on callback     window.close(); }, false); 

there's different question on stackoverflow may have better way listen application close instead of window close. process similar.