Is it possible to show hidden characters in CodeMirror?

Question

Is it possible to show hidden characters (like Carriage Return character) in Codemirror Text Editor, but I've not found any configuration reference about it in its documentation. Is it possible do this?

Answer 1

This could be done with help of overlays and predefined styles with whitespace and EOL symbol this way:

cm.addOverlay({
    name: 'invisibles',
    token:  function nextToken(stream) {
        var ret,
            spaces  = 0,
            peek    = stream.peek() === ' ';

        if (peek) {
            while (peek && spaces < Maximum) {
                ++spaces;

                stream.next();
                peek = stream.peek() === ' ';
            }

            ret = 'whitespace whitespace-' + spaces;
        } else {
            while (!stream.eol() && !peek) {
                stream.next();

                peek = stream.peek() === ' ';
            }

            ret = 'cm-eol';
        }

        return ret;
    }
});

You could use addon CodeMirror Show Invisibles for this purpose.