Question

I need a page action popup icon to appear when a tab has a specific URL in the address bar.

I have this in my background page

chrome.tabs.query({url:"MYURL.COM"} , function(tab)
            {
                for(i=0;i<tab.length;i++)
                {
                    console.log(tab[i].id);
                    chrome.pageAction.show(tab[i].id);
                }

            });

The popup shows whenever I reload the extension but as soon as user refreshes, it goes away and doesn’t come back.

Answer 1

The reason is that the background.js page is only loaded once, so you need to add a listener to every time the page tab is updated to check whether the page action should be shown, something like this:

chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) {
    if (tab.url.indexOf("MYURL.COM") > -1) {
        chrome.pageAction.show(tabId);
    }
});

There is no reason to iterate over each tab as you have done.