JavaScript JavaScript and the DOM Responding to User Interaction Event Delegation

Edmundo Ruiz
Edmundo Ruiz
3,488 Points

Cant get this one

I have tried everything I can think of.

index.html
<!DOCTYPE html>
<html>
    <head>
        <title>JavaScript and the DOM</title>
    </head>
    <link rel="stylesheet" href="style.css" />
    <body>
        <section>
            <h1>Making a Webpage Interactive</h1>
            <p>JavaScript is an exciting language that you can use to power web servers, create desktop programs, and even control robots. But JavaScript got its start in the browser way back in 1995.</p>
            <hr>
            <p>Things to Learn</p>
            <ul>
                <li>Item One: <input type="text"></li>
                <li>Item Two: <input type="text"></li>
                <li>Item Three: <input type="text"></li>
                <li>Item Four: <input type="text"></li>
            </ul>
            <button>Save</button>
        </section>
        <script src="app.js"></script>
    </body>
</html>
app.js
let section = document.getElementsByTagName('section')[0];

section.addEventListener('click', (e) => {
  e.target.style.backgroundColor = 'rgb(255, 255, 0)';
});

2 Answers

Dev Guy
Dev Guy
Full Stack JavaScript Techdegree Student 14,480 Points

Hi, Edmundo. I believe this was the instruction for the challenge; "In the listener that has been added to the section element, ensure that the text input elements are the only children that trigger the background-changing behavior." This is the solution for the challenge.

let section = document.getElementsByTagName('section')[0];

section.addEventListener('click', (e) => {
  if(e.target.tagName === "INPUT") {
  e.target.style.backgroundColor = 'rgb(255, 255, 0)';
  }
});

In order to ensure that the text input elements are the only children that trigger the background-changing behavior, you would need to use an if statement to check for the tag name of the event target. Remember the .tagName property returns the tag name of an element capitalized.... I hope this helps.

ingridg
ingridg
4,003 Points

Thank you soooo much, I totally forgot the tag name returns capitalized!!!

Brendan Whiting
MOD
Brendan Whiting
Front End Web Development Treehouse Moderator 82,989 Points

You can check to see what element has been clicked with e.target.tagName, and it expects a tag name in all caps. Check out 5:25 in the preceding video.