Question

Here is my most simple code:

var this_version =null;

this.timervar = setTimeout(function () {
    try {
        // Firefox 4 and later; Mozilla 2 and later
        Components.utils.import("resource://gre/modules/AddonManager.jsm");
        AddonManager.getAddonByID("[e-mail]", function(addon) {
            this_version = addon.version;
            alert("r "+this_version);
        });
    } catch (ex) {
        // Firefox 3.6 and before; Mozilla 1.9.2 and before
        var em = Components.classes["@mozilla.org/extensions/manager;1"]
            .getService(Components.interfaces.nsIExtensionManager);
        var addon = em.getItemForID("[e-mail]");
        this_version = addon.version;
        alert("rr " + this_version);
    }
    alert("rrr " + this_version);
}, 2000);

and its so damn strange because this fires twice alert("r "+this_version); but this alert("rrr "+this_version); always gives me null ;(

Still learning JS , so this is pretty puzzling… please help!

Thanks!

Answer 1

Ok, solved it by just moving all the stuff except for the alert out of the timer:

var this_version =null;
try {
    // Firefox 4 and later; Mozilla 2 and later
    Components.utils.import("resource://gre/modules/AddonManager.jsm");
    AddonManager.getAddonByID("[e-mail]", function(addon) {
        this_version = addon.version;
        alert("r "+this_version);
    });
} catch (ex) {
    // Firefox 3.6 and before; Mozilla 1.9.2 and before
    var em = Components.classes["@mozilla.org/extensions/manager;1"]
        .getService(Components.interfaces.nsIExtensionManager);
    var addon = em.getItemForID("[e-mail]");
    this_version = addon.version;
    alert("rr " + this_version);
}

this.timervar = setTimeout(function ()
                            { 



                                    alert("rrr "+this_version);


                            }, 2000);