Detect pasted text with ctrl+v or right click -> paste

Question

How to detect what text the user pastes in textarea with JS?

Answer 1

Following may help you

  function submitenter(myfield,e)
  {
    var keycode;
    if (window.event) keycode = window.event.keyCode;
    else if (e) keycode = e.which;
    else return true;
    if (keycode == //event code of ctrl-v)
    {
      //some code here
    }

  }

  <teaxtarea name="area[name]" onKeyPress=>"return submitenter(this,event);"></textarea> 

Answer 2

You could use the paste event to detect the paste in most browsers (notably not Firefox 2 though). When you handle the paste event, record the current selection, and then set a brief timer that calls a function after the paste has completed. This function can then compare lengths and to know where to look for the pasted content. Something like the following. For the sake of brevity, the function that gets the textarea selection does not work in IE. See here for something that does: http://stackoverflow.com/questions/3053542/how-to-get-the-start-and-end-points-of-selection-in-text-area/3053640#3053640

function getTextAreaSelection(textarea) {
    var start = textarea.selectionStart, end = textarea.selectionEnd;
    return {
        start: start,
        end: end,
        length: end - start,
        text: textarea.value.slice(start, end)
    };
}

function detectPaste(textarea, callback) {
    textarea.onpaste = function() {
        var sel = getTextAreaSelection(textarea);
        var initialLength = textarea.value.length;
        window.setTimeout(function() {
            var val = textarea.value;
            var pastedTextLength = val.length - (initialLength - sel.length);
            var end = sel.start + pastedTextLength;
            callback({
                start: sel.start,
                end: end,
                length: pastedTextLength,
                text: val.slice(sel.start, end)
            });
        }, 1);
    };
}

var textarea = document.getElementById("your_textarea");
detectPaste(textarea, function(pasteInfo) {
    alert(pasteInfo.text);
    // pasteInfo also has properties for the start and end character
    // index and length of the pasted text
});