Use CodeMirror for standalone syntax highlighting with line numbers

Question

I use CodeMirror V. 3 for stand alone syntax highlighting (other parts of my project also uses the CodeMirror editor, so I don't want to use other standalone-syntax highlighting libraries like google-code-prettify).

I use the lib/runmode.js script as described in the CodeMirror: Mode Runner Demo to highlight code in a <pre>-tag. This works fine. Now I want to add line numbers on the left side of the code just like in the CodeMirror editor.

(The CodeMirror.runMode have an options argument, but this seems to work only with the tabsize. Any idea how I can add linenumbers to my code (like in google-code-prettify the css-class linenums)?)

Answer 1

I would hack Mode Runner like this

  CodeMirror.runMode = function(string, modespec, callback, options) {
  var mode = CodeMirror.getMode(CodeMirror.defaults, modespec);
   var lineNumber = 1; // Line number
   if (callback.nodeType == 1) {
    var tabSize = (options && options.tabSize) || CodeMirror.defaults.tabSize;
    var node = callback, col = 0;
    node.innerHTML = "";
    callback = function(text, style) {


      if (text == "\n") {

      lineNumber++ ; //increment line number
      var lineNum = document.createTextNode(lineNumber); // 

      node.appendChild(document.createElement("br"));

      node.appendChild(lineNum); // append
        col = 0;
        return;
      }
      var content = "";
      // replace tabs
      for (var pos = 0;;) {
      var lineNum = document.createTextNode(lineNumber + " ")
        var idx = text.indexOf("\t", pos);
        if (idx == -1) {
          content += text.slice(pos);
          col += text.length - pos;

          break;
        } else {
          col += idx - pos;
          content += text.slice(pos, idx);
          var size = tabSize - col % tabSize;
          col += size;
          for (var i = 0; i < size; ++i) content += " ";
          pos = idx + 1;

        }
      }

      if (style) {
        var sp = node.appendChild(document.createElement("span"));
        sp.className = "cm-" + style.replace(/ +/g, " cm-");
        sp.appendChild(document.createTextNode(content));
      } else {
        node.appendChild(document.createTextNode(content));
      }
    };
  }

  var lines = CodeMirror.splitLines(string), state = CodeMirror.startState(mode);
  for (var i = 0, e = lines.length; i < e; ++i) {
    if (i) callback("\n");
    var stream = new CodeMirror.StringStream(lines[i]);
    while (!stream.eol()) {
      var style = mode.token(stream, state);
      callback(stream.current(), style, i, stream.start);
      stream.start = stream.pos;
    }
  }
// add the first line
 var outputDiv = document.getElementById("output");
  var firstLine = document.createTextNode("1 ");
  outputDiv.insertBefore(firstLine, outputDiv.firstChild);
};