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JavaScript jQuery Basics (2014) Creating a Simple Lightbox A Better Caption

$image.attr("src","imageLocation")

Why do we need to replace "src" with "imageLcation"?

//Problem: User when clicking on image goes to a dead end //Solution: Create an overlay with the large image - Lightbox

var $overlay = $('<div id="overlay"></div>'); var $image = $("<img>"); var $caption = $("<p></p>");

//An image to overlay $overlay.append($image);

//A caption to overlay $overlay.append($caption);

//Add overlay $("body").append($overlay);

//Capture the click event on a link to an image $("#imageGallery a").click(function(event){ event.preventDefault(); var imageLocation = $(this).attr("href"); //Update overlay with the image linked in the link $image.attr("src", imageLocation);

//Show the overlay. $overlay.show();

//Get child's title attribute and set caption var captionText = $(this).children("img").attr("alt"); $caption.text(captionText); });

//When overlay is clicked $overlay.click(function(){ //Hide the overlay $overlay.hide(); });

js/app.js
//Problem: User when clicking on image goes to a dead end
//Solution: Create an overlay with the large image - Lightbox

var $overlay = $('<div id="overlay"></div>');
var $image = $("<img>");
var $caption = $("<p></p>");

//An image to overlay
$overlay.append($image);

//A caption to overlay
$overlay.append($caption);

//Add overlay
$("body").append($overlay);

//Capture the click event on a link to an image
$("#imageGallery a").click(function(event){
  event.preventDefault();
  var imageLocation = $(this).attr("href");
  //Update overlay with the image linked in the link
  $image.attr("src", imageLocation);

  //Show the overlay.
  $overlay.show();

  //Get child's title attribute and set caption
  var captionText = $(this).children("img").attr("alt");
  $caption.text(captionText);
});

//When overlay is clicked
$overlay.click(function(){
  //Hide the overlay
  $overlay.hide();
});
index.html
<!DOCTYPE html>
<html>
<head>
    <link rel="stylesheet" href="css/style.css" type="text/css" media="screen" title="no title" charset="utf-8">
    <title>Image Gallery</title>
</head>
<body>
  <h1>Image Gallery</h1>
  <ul id="imageGallery">
    <li><a href="images/refferal_machine.png"><img src="images/refferal_machine.png" width="100" alt="Image of Refferal Machine" title="Refferal Machine By Matthew Spiel"></a></li>
    <li><a href="images/space-juice.png"><img src="images/space-juice.png" width="100" alt="Image of Space Juice" title="Space Juice by Mat Helme"></a></li>
    <li><a href="images/education.png"><img src="images/education.png" width="100" alt="Image of Education" title="Education by Chris Michel"></a></li>
    <li><a href="images/copy_mcrepeatsalot.png"><img src="images/copy_mcrepeatsalot.png" width="100" alt="Image of Wanted: Copy McRepeatsalot" title="Wanted: Copy McRepeatsalot by Chris Michel"></a></li>
    <li><a href="images/sebastian.png"><img src="images/sebastian.png" width="100" alt="Image of Sebastian" title="Sebastian by Mat Helme"></a></li>
    <li><a href="images/skill-polish.png"><img src="images/skill-polish.png" width="100" alt="Image of Skill Polish" title="Skill Polish by Chris Michel"></a></li>
    <li><a href="images/chuck.png"><img src="images/chuck.png" width="100" alt="Image of Chuck" title="Chuck by Mat Helme"></a></li>
    <li><a href="images/library.png"><img src="images/library.png" width="100" alt="Image of Library" title="Library by Tyson Rosage"></a></li>
    <li><a href="images/boat.png"><img src="images/boat.png" width="100" alt="Image of Boat" title="Boat by Griffin Moore"></a></li>
    <li><a href="images/illustrator_foundations.png"><img src="images/illustrator_foundations.png" width="100" alt="Image of Illustrator Foundations" title="Illustrator Foundations by Matthew Spiel"></a></li>
    <li><a href="images/treehouse_shop.jpg"><img src="images/treehouse_shop.jpg" width="100" alt="Image of Treehouse Shop" title="Treehouse Shop by Eric Smith"></a></li>
  </ul>
  <script src="//code.jquery.com/jquery-1.11.0.min.js" type="text/javascript" charset="utf-8"></script>
  <script src="js/app.js" type="text/javascript" charset="utf-8"></script>
</body>
</html>

2 Answers

Steven Parker
Steven Parker
229,785 Points

In the original HTML, the links have all been set up to target the URL where the full-size version of the image is located. In an anchor (a) tag, the attribute that holds the target URL is "href". So the code first copies the value from the href attribute of the link element into the local variable named imageLocation.

Then, since an image (img) tag displays an image based on the "src" attribute, the URL saved in the imageLocation variable is then copied into that attribute of the existing image element in the overlay. This changes what is being shown in that element so that it now displays the full-size version of the smaller image that was clicked on in the gallery.

Thank you for your answer Steve!