Question

I have a very very simple bit of code in my (test) Chrome extension:

    function test()
    {
    alert("In test!");
    }

   chrome.tabs.onUpdated.addListener(function(tabid, changeinfo, tab) {
    var url = tab.url;
        if (url !== undefined) {

        test();
    }
   });

My question is, why is test() firing twice? And more importantly, how do I make it fire just once?

Answer 1

Have a look at what the different states are when the event is dispatched. I presume, that it is getting dispatched once when the state is “loading” or when the state is “complete”. If that is the case, then your problem would be fixed with:

 function test()
    {
    alert("In test!");
    }

   chrome.tabs.onUpdated.addListener(function(tabid, changeinfo, tab) {
    var url = tab.url;
        if (url !== undefined && changeinfo.status == "complete") {

        test();
    }
   });