wait for document.body existence

Question

I wrote a chrome extension that works before the page is loaded (using the attribute \"run_at\": \"document_start\"). The problem is that I want to add a

Answer 1

You can use DOMContentLoaded event which is similar to $(document).ready()

document.addEventListener("DOMContentLoaded", function(event) {
   console.log("DOM fully loaded and parsed");
});

MDN says

The DOMContentLoaded event is fired when the document has been completely loaded and parsed, without waiting for stylesheets, images, and subframes to finish loading (the load event can be used to detect a fully-loaded page).