Building a Chrome extension where I need to have a script be activated when the user highlights text

Question

Anyone know if there is a trigger for this or variable I can poll to check if something is currently highlighted on the page?

Answer 1

You can check if a "mouseup"-event was fired and then get the currently selected text:

document.onmouseup = ()=>{
  selection = window.getSelection().toString()
    if(selection){
      alert(`"${selection}" is highlighted`)
    }
}

Select me!

(Read Selected text event trigger in Javascript)