Practice Set, Week 8, DOM Traversal

by IrfanMalik

HTML

<h3>Practice Set, Week 8, DOM Traversal</h3>

<p>Code is provided here that will traverse the DOM. Your job is to add some code that will take some action at each node.</p>
<p>Your task is to find every element that has the word "text" in it, and add the className "searchHit" to their parent elements.</p>
<p>The steps to do this will look something like this:</p>
<ol>
  <li>At each node, determine if it's a text node</li>
  <li>If so, find out if the target string is within the text content of the node.</li>
  <li>If so, get the parent node and set its class attribute to "searchHit"</li>
</ol>
<p>If you've got it, each element containing the word 'text' will be highlighted in yellow. </p>

CSS

.searchHit {
  background-color: yellow;
}

JavaScript

function traverse(el, str) {
  for (var i = 0; i < el.childNodes.length; i++) {
    traverse(el.childNodes[i], str)
      // Or your code can go here - acting on the way back up 
      //  the tree towards the root
    //as the search string is text the nodeType is 3
    if (el.childNodes[i].nodeType == 3) {
      var nodeList = el.childNodes[i];
      nodeList = nodeList.textContent;
      var stringList = nodeList.toString();
      var n = stringList.search("text")
      if (n > 0) {
        el.childNodes[i].parentNode.className = "searchHit";
      }
    }
  }
}

traverse(document.documentElement, 'text');