Question

I’m having a trouble with a statusbar’s label value, which is set by a function. I have to save this value before the user closes the browser, recover it and run the function again.
the only way i think it’s possible is using cookies.
I’ve found 2 interesting codes in MDN:
For setting cookies:

var ios = Components.classes["@mozilla.org/network/io-service;1"].getService(Components.interfaces.nsIIOService); 
    var cookieUri = ios.newURI("http://www.yourplacewhereyouwanttosetthecookie.com/", null, null); 
    var cookieSvc = Components.classes["@mozilla.org/cookieService;1"].getService(Components.interfaces.nsICookieService); 

    cookieSvc.setCookieString(cookieUri, null, "your_key=your_value;", null); 

and for reading them:

var ios = Components.classes["@mozilla.org/network/io-service;1"] 
                .getService(Components.interfaces.nsIIOService); 
    var uri = ios.newURI("http://www.google.com/", null, null); 
    var cookieSvc = Components.classes["@mozilla.org/cookieService;1"] 
                      .getService(Components.interfaces.nsICookieService); 
    var cookie = cookieSvc.getCookieString(uri, null);  

the problem is that i can’t understand this. where i can put my statusbar’s label? what does “your_key=your_value” mean? how i can recover this value using the reading code? why i have to set an internet address at “newURI”?
i’m sorry, but i’m still learning it 🙂 . will be glad if i get some help.
Thanks a lot!

Answer 1

It’d probably be better to use preferences to save that info. Add a preference to your default preferences js file e.g. pref("extensions.myextension.thelabelvalue", "whatever");
https://developer.mozilla.org/en/Building_an_Extension#Defaults_Files

Then add Components.utils.import("resource://gre/modules/Services.jsm"); to the top of your main javscript file https://developer.mozilla.org/en/JavaScript_code_modules/Services.jsm

and you can then use the set/get preference methods listed here: https://developer.mozilla.org/en/XPCOM_Interface_Reference/nsIPrefBranch

e.g.

let myPrefs=Services.prefs.getBranch("extensions.myextension.")
myPrefs.setCharPref('thelabelvalue', text_value_from_label);
myPrefs.getCharPref('thelabelvalue');