What is Object details in Chrome.* API - api

Question

I am learning Chrome extension development from the official documentation and learned a bit but I need understanding what it means by object details in API function parameters. For example one of browserAction method getTitle signature is
chrome.browserAction.getTitle(object details, function callback)
//object details integer (optional) tabId
Now I write in background.js
chrome.browserAction.getTitle({}, titleShow);
function titleShow(t){
console.log('tab title:' + t);
}
and it show title of my extension.As you can see here I send blank object {}.
How do I get tabId on very first line and send it with this method?
Does this method return tab Title if we send tab id?

Answer 1

You are asking questions that are easy to answer, just check the documentation and you'll see the details of the chrome.browserAction.getTitle() method (and all the other methods of the Chrome APIs).
Quoting from the documentation:
chrome.browserAction.getTitle(object details, function callback)
Gets the title of the browser action.
Parameters:
object details:
integer (optional) tabId. Specify the tab to get the title from. If no tab is specified, the non-tab-specific title is returned.
function callBack. The callback parameter should be a function that looks like this: function(string result) {...};
string result.
So, to answer your questions:
To get the tab id on the first line you've got to use the chrome.tabs.query() method (see documentation), request the tab with the details you're interested in and use its ID in the callback, something like this:
chrome.tabs.query({active: true, currentWindow: true}, function(tabs) {
chrome.browserAction.getTitle({tabId: tabs[0].id}, function(result) {
console.log("Browser action title:", result);
});
});
Browser actions can have different titles on different tabs. To set a different title for each tab you have to use the chrome.browserAction.setTitle() method. So if you send the tabId in the details object of the chrome.browserAction.getTitle() method, you'll not get the tab title, you'll only get the tab-specific title of the browser action. To get a specific tab title you should use the chrome.tabs.query() method.