nsISessionStore
astring getwindowstate(in nsidomwindow awindow); astring getwindowvalue(in nsidomwindow awindow, in astring akey); void init(in nsidomwindow awindow); void persisttabattribute(in astring aname); void restorelastsession(); void setbrowserstate(in astring astate); void settabstate(in nsidomnode atab, in astring astate); void settabvalue(in nsidomnode atab, in astring akey, in astring astringvalue); void setwindowstate(in nsidomwindow awindow, in astring astate, in boolean aoverwrite); void setwindowvalue(in nsidomwindow awindow, in astring akey, in astring astringvalue); nsidomnode undoclosetab(in nsidomwindow awindow, in unsigned long aindex); nsidomwindow undoclosewindow(in unsigned long ain...
... return value the string value that was previously assigned to akey using nsisessionstore.settabvalue(), or an empty string if no value is set for that key.
...nsisessionstore.settabvalue().
...And 3 more matches

Session store API - Archive of obsolete content
in order to properly restore your extension's state when a tab is restored, it needs to use the session store api's settabvalue() method to save any data it will need in order to restore its state, and then call gettabvalue() to retrieve the previous setting when the tab is restored.
... var ss = components.classes["@mozilla.org/browser/sessionstore;1"] .getservice(components.interfaces.nsisessionstore); var currenttab = gbrowser.selectedtab; var datatoattach = "i want to attach this"; ss.settabvalue(currenttab, "key-name-here", datatoattach); this code sets the value of the key "key-name-here" to datatoattach.