Frame script environment
domwindowcreated fires when a new content object is created.

Frame script environment
domwindowcreated fires when a new content object is created.

Frame script loading and lifetime
if you want a frame script to do something when a new document is loaded, you need to listen for an appropriate dom event, generally domwindowcreated, domcontentloaded, or load.

Performance
better: content-document-global-created notifications can be substituted with domwindowcreated events other observers and services should be registered in a process script or jsm instead load frame scripts on demand bad: // addon.js services.mm.loadframescript("framescript.js", /*delayed:*/ true) // stuff communicating with the framescript // framescript.js function onlyonceinabluemoon() { // we only need this during a total solar eclipse while goat blood rains from the sky ...

Event reference
domwindowcreated addons specific a window has been created.