Overview

Most Web sites have images. There are many different features and functionality that can be used to work with images via the use of JavaScript. These include preloading, rollovers, and cycling banner ads. In this assessment, you will be working with JavaScript, images, and events, and you will be manipulating the DOM to create an interactive image gallery.

Hint: Preloading your images will only work on a hosting server and not your local drive as there’s no load time for your images locally. Once you have preloaded those images, you may want to clear your cache to test your loading of the images again.

Tip: In a smaller JavaScript program such as this one, each function is created for a specific purpose. However, in more complex sites, it is better to build functions that we can apply to multiple situations. For example, rather than specifying an element name or id, we can use a variable that is passed into the function.

Directions

Use the gallery.html and index.html files that you downloaded in the Zip file in Assessment 1. Create functionality using JavaScript on the following pages:

index.html

• Preload the images (banner1.jpg, banner2.jpg and banner3.jpg found in the images folder) for the banner at the top of the page.
• Create a cycling two-state banner that cycles every three seconds.

gallery.html

• Preload the gallery images.
• Create rollover functionality for each of the thumbnails in your image gallery. Use appropriate images found in the images folder.
• Write developer comments to describe the variables being declared and explain the functions and logical blocks of JavaScript code pertaining to the gallery.

Make sure to do the following:

• Create an onpageload function to preload all of your images.
• Create a modularized function to cycle the homepage banner.
• Create a modularized rollover function for gallery images.
• Once completed, view your pages in each of your two selected Web browsers to see if the content renders appropriately and consistently within each. Next, verify that your code is error-free using the appropriate browser-specific development tool found in the Resources. Take a screen capture of each of your validation results and save it for submission.

Note: “Modularized” refers to creating components that can be re-purposed without significant changes to coding. Modularized components have no “hard coding” of image names, urls, et cetera, in the functions. There is an example JavaScript modularized and non-modularized JavaScript found in the Suggested Resources in the file called “Example Code.”

Submission Requirements

• Upload your Web site files to your Web host.
• Submit your work in the courseroom using a single Zip file containing the following:
  • Your entire Web site including all associated files.
  • A Word document with:
    • The url to your Web site so faculty can view your site on a live host.
    • A screen capture of each of your two validations that you completed using the developer tools found in the Resources.