This is a project from the Udacity Front-End Web Developer nanodegree. This project focused on optimizing an existing web site. The overall goals were two-fold:

1. Optimize PageSpeed Insights score for index.html - this involves making improvements to the Critical Rendering Path (CRP). Needs to be a PageSpeed score above 90.
2. Optimize Frames Per Second in pizza.html - this involves stabilizing the Frames Per Second (FPS) to 60 fps in pizza.html while scrolling, as well as improving the time to re-size the pizzas to below 5ms. Comments in views/js/main.js are present and effectively explain longer code procedures.

You can load the website in two ways:

1. From this GitHub pages - open the website.

2. Download the repo locally - You can either download a zip file from the repo or you can clone the repo onto your local machine. Once downloaded onto your local machine, you can do one of two things to view: -- Open the dist/index.html file that is in the root directory of the repo, with a browser (i.e. Chrome, Firefox). -- Host the files through a local web server, and use your browser to navigate to the local web server. For example, if you have python installed, you can run this command in the root of the repo directory to serve the files:

   python -m SimpleHTTPServer 8080 # assuming port 8080 is not used already.
   

   Then you can navigate your browser to localhost:8080/dist/

• Minified CSS with htmlmin to reduce file size
• Minified JS with uglify-js to reduce file size
• Inlined CSS to avoid another round trip with inline-source
• Inlined JS to avoid another round trip with inline-source
• Added async to analytics.js to stop blocking
• Moved javascript to end of body to stop blocking
• Reduced size of all images using convert on the command line to reduce file size
• removed Google web fonts
• Added media=“print” to print.css link

index.html Page Speed Insight analysis
pizza.html Page Speed Insight analysis

• Based on dev tools, saw that changePizzaSizes was taking a long time to resize all pizzas. The problem was that the size of each element was being calculated for each loop iteration, when the size is the same for all pizzas. So, I took the calculation out of the loop, and the time to resize got reduced significantly.

  Old Timing

   Time to resize pizzas: 108.80000004544854ms  main.js:465 
   Time to resize pizzas: 110.7999999076128ms   main.js:465 
   Time to resize pizzas: 82.00000005215406ms   main.js:465
  

  New Timing

   Time to resize pizzas: 2.800000016577542ms   main.js:470 
   Time to resize pizzas: 2.300000051036477ms   main.js:470
   Time to resize pizzas: 2.3999999975785613ms  main.js:470
  

• Based on dev tools, saw that the FPS were low. Since the scroll event triggered the function updatePositions, modified that function to perform better.

  1. First took the scrollTop calculation out of the loop, since only need once
  2. implemented requestAnimationFrame based on course discussion about allowing for smoother FPS

  The FPS went up from around ~20 FPS to about ~60 FPS

Used Gulp to automate the building and common tasks of the website. Includes the following:

• minification of javascript using uglify
• minification of HTML and CSS using htmlmin
• inlining CSS using inline source
• Javascript linting using jshint
• CSS linting using csslint
• moves all assets under the dist/ directory

Gulp dependencies are in the package.json file

You need to install nodejs/npm and gulp first.

To generate distribution, run the following in the root directory of the repo

Install Dependencies

npm install

Generate Distribution

gulp main

You can run individual tasks by replacing main with either html, css,js or img The resulting files for distribution will be in the dist/ directory

• Google Page Speed Insights - tool to measure web page performance
• convert - CLI tool to resize and optimize images
• Chrome Dev Tools tips-and-tricks
• Optimizing Performance
• gulp - build/task tool to automate common tasks (i.e. minifications, inlining)
• gulp-htmlmin - tool to minimize the HTML and CSS
• gulp-uglify - tool to minimize the Javascript files
• gulp-inline-source - Tools to inline CSS into the HTML page from gulp
• gulp-csslint - tool to check syntax of CSS from Gulp
• gulp-jshint - tool to check syntax of javascript files from Gulp

This project is licensed under the terms of the MIT license. (See LICENSE.md)

Copyright (c) 2018 Brett Schwarz