Exercises from Chapter 12 of Eloquent Javascript

Chapter12.js

// Ex. 12.1

//Write a function asHTML which, when given a DOM node, 
//produces a string representing the HTML text for that node 
//and its children. You may ignore attributes, just show nodes 
//as <nodename>. The escapeHTML function from chapter 10 is 
//available to properly escape the content of text nodes.

function escapeHTML(text) {
  var replacements = {"<": "&lt;", ">": "&gt;",
                      "&": "&amp;", "\"": "&quot;"};
  return text.replace(/[<>&"]/g, function(character) {
    return replacements[character];
  });
}

function isTextNode(node) {
  return node.nodeType == 3;
}

function asHTML (node) {
    document.write("<"+node.nodeName+"><br>");
    if (isTextNode(node))
	document.write(escapeHTML(node.nodeValue) + "<br>");
    for (var child in node.childNodes)
	asHTML(child);
    document.write("</"+node.nodeName+"><br>");
}

// my solution does not work. I get an undefined. I don't know why. 

// function asHTML(node) {
//  if (isTextNode(node))
//    return escapeHTML(node.nodeValue);
//  else if (node.childNodes.length == 0)
//    return "<" + node.nodeName + "/>";
//  else
//    return "<" + node.nodeName + ">" +
//            map(asHTML, node.childNodes).join("") +
//           "</" + node.nodeName + ">";
// }

// Okay, I peeked as the solution in the book and that works fine of course

// Ex. 12.2
function removeElement (node) {
    node.parentNode.removeChild(node);
}

// okay, I forgot to check whether it's the root node itself in which case, 
// it wouldn't have a parent node.