CODEWITHSUNDEEP
javascriptfirefoxfirefox-addoninstance
Aley
Aley

Reputation: 8640

Firefox extension dev: How to set an observer only once

I've created a tiny Firefox extension with just a small snippet of code. Something like this:

var load = function() {
    Components.classes['@mozilla.org/observer-service;1'].getService(Components.interfaces.nsIObserverService).addObserver({
            observe: function(subject, topic, data) {
                    var channel = subject.QueryInterface(Components.interfaces.nsIHttpChannel);
                    if(/google\.com/.test(channel.originalURI.host)) {
                            // magic here
                    }
            }
    }, 'http-on-modify-request', false);
};

window.addEventListener('load', load, false);

When I submit this plugin to Firefox Addons, I get the following as return:

You're creating an HTTP observer for every opened window, while there should be just a single instance.

Now how do I create a single observer instance?

Upvotes: 1

Views: 258

Answers (1)

Piotr Wu
Piotr Wu

Reputation: 1362

You should use JS code module. In your overlay script put:

Cu.import("resource://yourPluginName/yourModule.jsm");

and in your yourModule.jsm and only there put your observer for example:

const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
var observerService = Cc["@mozilla.org/observer-service;1"]
    .getService(Ci.nsIObserverService);
observerService.addObserver(testObs, "http-on-examine-response", false);

var testObs = {
    observe: function(aSubject, aTopic, aData){
        //...
    } 
}

And BTW in jsm, you can't use window object.

Upvotes: 1

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