Practice Set, Week 8, DOM Traversal

by mtzara

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) {
//looking through el for str
    // Your code can go here - acting on the way down 
    //   the tree towards the branches
    
    if(el.nodeType == 3) {
 //looking for a text node. node.TEXT_NODE is a constant that always equals 3   
    	if(typeof el.nodeValue == "string" && el.nodeValue.indexOf(str) > -1){
  //also checking if our textNode has a nodeValue of string otherwise indexOf(str) won't work    
 //will have to check el.nodeValue to see if it's got str within it.     
      	el.parentNode.setAttribute('class', 'searchHit');
 //give the parentNode a clas of searchHit       
      }
    }
    
    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
        
}
traverse(document.documentElement, 'text');