Chrome extension not running on back button

Question

I am writing a chrome extension that needs to run every time certain webpages are loaded.

Currently when I first load a page the script runs. However if I then go to another page and click "Back" so it returns to the original page, the script does not run. If I then refresh the page it does run the script.

I suspect this is something to do with chrome not running extensions if it is loading a cached version of the page? (Might be total rubbish).

Currently the manifest file says to "run_at" "document_end".

Anyone have any clue how I can make it run the script even when I open the page by navigating "Back"?

Answer 1

It doesn't run because, like the rest of the scripts on the page, they've already run and potentially altered the content. This behavior is native to browsers and it's called back/forward cache.

You can include a pageshow event listener into your content script. For example:

// contentscript.js

function init () {
  alert('Good soup')
}

window.addEventListener('pageshow', init);

The pageshow event is sent to a Window when the browser displays the window's document due to navigation.

This includes:

• Initially loading the page
• Navigating to the page from another page in the same window or tab
• Restoring a frozen page on mobile OSes
• Returning to the page using the browser's forward or back buttons