List Open Tabs

To list the open tabs, you can iterate over the tabs object itself.

The following add-on adds an action button that logs the URLs of open tabs when the user clicks it:

require("sdk/ui/button/action").ActionButton({
  id: "list-tabs",
  label: "List Tabs",
  icon: "./icon-16.png",
  onClick: listTabs
});

function listTabs() {
  var tabs = require("sdk/tabs");
  for (let tab of tabs)
    console.log(tab.url);
}

Run the add-on, load a couple of tabs and click the button. You'll see output in the command line console that looks something like this:

info: https://www.mozilla.org/en-US/about/
info: https://www.bbc.co.uk/

You don't get direct access to any content hosted in the tab. To access tab content, you need to attach a script to the tab using tab.attach(). This add-on attaches a script to all open tabs. The script adds a red border to the tab's document:

require("sdk/ui/button/action").ActionButton({
  id: "list-tabs",
  label: "List Tabs",
  icon: "./icon-16.png",
  onClick: listTabs
});

function listTabs() {
  var tabs = require("sdk/tabs");
  for (let tab of tabs)
    runScript(tab);
}
 
function runScript(tab) {
  tab.attach({
    contentScript: "document.body.style.border = '5px solid red';"
  });
}

Learning More

To learn more about working with tabs in the SDK, see the tabs API reference.

To learn more about running scripts in tabs, see the tutorial on using tab.attach().