event.clipboardData.setData in copy event

Question

I have looked at many posts but could not find a clear current answer to the following two questions as it seems standards and browser support has been constantly changing.<

Answer 1

You can also just turn it into a function that calls its own handler and removes it

function copyStringToClipboard (string) {
    function handler (event){
        event.clipboardData.setData('text/plain', string);
        event.preventDefault();
        document.removeEventListener('copy', handler, true);
    }

    document.addEventListener('copy', handler, true);
    document.execCommand('copy');
}