How to Paste code to NoVNC.

NoVNC_Paste.js

// This will open up a prompt for text to send to a console session on digital ocean
//  Useful for long passwords
(function () {        
    window.sendString = function (str) {
        f(str.split(""));
        function f(t) {
            var character = t.shift();
            var i=[];
            var code = character.charCodeAt();
            var needs_shift = character.match(/[A-Z!@#$%^&*()_+{}:\"<>?~|]/);
            if (needs_shift) {
                rfb.sendKey(XK_Shift_L,1);
            }
            rfb.sendKey(code,1);
            rfb.sendKey(code,0);
            if (needs_shift) {
                rfb.sendKey(XK_Shift_L,0);
            }
            
            if (t.length > 0) {
                setTimeout(function() {f(t);}, 10);
            }
        }
    }
})();


# Minified Version:
(function(){window.sendString=function(a){function b(c){var d=c.shift(),g=d.charCodeAt(),h=d.match(/[A-Z!@#$%^&*()_+{}:\"<>?~|]/);h&&rfb.sendKey(XK_Shift_L,1),rfb.sendKey(g,1),rfb.sendKey(g,0),h&&rfb.sendKey(XK_Shift_L,0),0<c.length&&setTimeout(function(){b(c)},10)}b(a.split(""))}})();

Glad that helps you. These characters should be handled by this:

            var needs_shift = character.match(/[A-Z!@#$%^&*()_+{}:\"<>?~|]/);
            if (needs_shift) {
                rfb.sendKey(XK_Shift_L,1);
            }

It means, should "press" SHIFT and the key.

This code doesn't support new lines

Did you try:

sendString("mychars\r\nother chars");  # Maybe your client accepts \r\n as new line. 

Did you try:

sendString("mychars\r\nother chars");  # Maybe your client accepts \r\n as new line. 

Yup, tried \r, \n, \r\n.
And even tried rfb.sendKey(13, true). None worked, it feels like noVNC don't accept new lines in this function or something.