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.
Is it a legal operation according to the standard to change the clipboard with event.clipboardData.setData inside a 'copy' event handler?
Clipboard APIs were indeed in active development as of 2016, but things have stabilized since then:
Changing the clipboard with event.clipboardData.setData() inside a 'copy' event handler is allowed by the spec (as long as the event is not synthetic).
Note that you need to prevent the default action in the event handler to prevent your changes from being overwritten by the browser:
document.addEventListener('copy', function(e){ e.clipboardData.setData('text/plain', 'foo'); e.preventDefault(); // default behaviour is to copy any selected text }); If you need to trigger the copy event (and not just handle the copy requests made by the user via the browser UI), you must use document.execCommand('copy'). It will only work in certain handlers, such as the click handler:
document.getElementById("copyBtn").onclick = function() { document.execCommand('copy'); } clipboardData in the copy/cut/paste events (since Firefox 22) and execCommand('copy') from user actions (since Firefox 41)execCommand('copy').https://github.com/garykac/clipboard/blob/master/clipboard.md has a compatibility table for execCommand(cut / copy / paste).
You can test this using the snippet below, please comment with the results.
window.onload = function() { document.addEventListener('copy', function(e){ console.log("copy handler"); if (document.getElementById("enableHandler").checked) { e.clipboardData.setData('text/plain', 'Current time is ' + new Date()); e.preventDefault(); // default behaviour is to copy any selected text } // This is just to simplify testing: setTimeout(function() { var tb = document.getElementById("target"); tb.value = ""; tb.focus(); }, 0); }); document.getElementById("execCopy").onclick = function() { document.execCommand('copy'); // only works in click handler or other user-triggered thread } document.getElementById("synthEvt").onclick = function() { var e = new ClipboardEvent("copy", {dataType: "text/plain", data:"bar"}); document.dispatchEvent(e); } }<html> <input id="enableHandler" type="checkbox" checked> <label for="enableHandler">Run clipboardData.setData('text/plain', ...) in the "copy" handler</label> <p>Try selecting this text and triggering a copy using</p> <ul> <li><button id="execCopy">document.execCommand('copy')</button> - should work.</li> <li><button id="synthEvt">document.dispatchEvent(clipboardEvent)</button> - should NOT work</li> <li>with keyboard shortcut - should work</li> <li>or from the context menu - should work</li> </ul> <p>If the "copy" handler was triggered, the focus will move to the textbox below automatically, so that you can try pasting from clipboard:</p> <input type="text" id="target" size="80">When implemented, navigator.clipboard will let you write code like this:
navigator.clipboard.writeText('Text to be copied') .then(() => { console.log('Text copied to clipboard'); }) .catch(err => { // This can happen if the user denies clipboard permissions: console.error('Could not copy text: ', err); }); Chrome 66 starts shipping a partial implementation, and they've published an article about the new API.
TypeError: undefined is not an object (evaluating 'navigator.clipboard.writeText')
.clipboardData.setData() is it possible to set both text/plain and text/html carriers? I can seem only to one or the other.
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'); } 
event.clipboardData.setData only works reliably when triggered from user generated copy/paste/similar events. Because of this, the above copyStringToClipboard will not work in the general case since the copy event generated by the call to document.execCommand is synthetic.Bind the element id with copy event and then get the selected text. You could replace or modify the text. Get the clipboard and set the new text. To get the exact formatting you need to set the type as "text/hmtl". You may also bind it to the document instead of element.
$(ElementId).bind('copy', function(event) { var selectedText = window.getSelection().toString(); selectedText = selectedText.replace(/\u200B/g, ""); clipboardData = event.clipboardData || window.clipboardData || event.originalEvent.clipboardData; clipboardData.setData('text/html', selectedText); event.preventDefault(); }); For this, we can use browser API. It's worked for me
async copyClipboard(string){ await navigator.clipboard.writeText(string); console.log("Text copied"); } 
There are several answers here that reference execCommand(). This feature is deprecated.
For modern browser support its best to use writeText() which is part of the Clipboard interface.
A simple example would be:
navigator.clipboard.writeText(value) .then(() => { console.log(value + " copied to clipboard"); }) .catch(err => { // This can happen if the user denies clipboard permissions: console.error('Could not copy text: ', err); }); 
