Note This card does not reflect the current state of lazy loading technologies. The native lazy attribute could be used...
You want to test your 1GE or 10GE internet uplink? We needed to ensure we have full 10GE to the...
Rails 4 introduced raising an error on pending migrations. This is most annoying when you are crafting a migration but...
Our applications not only need to be functional, they need to be fast. But, to quote Donald Knuth, premature optimization...
Some tasks in a web application are better not done live when a user request a page, but in the...
I recommend install Node.js using nvm. This way you can have multiple Node versions in your ~/.nvm. You also won...
You have the following HTML structure:
If you want to run Javascript code whenever someone clicks on a ...
..., you...
Built-in matchers Get an overview of all the matchers that are built into RSpec. Play with some of...
Learn to store attachments in a way that is accessible by authorized users only Learn to prevent users from...
Exercise 1: Maps In MovieDB, add a new field “Principal filming location”. In a movie’s show view, geocode that...
Stepping forward from JavaScript Basics, the goal of this card is for you to be able to read and write...
A common task in web applications is to add client-side JavaScript behavior to existing HTML elements.
If you see a stacktrace beginning with lines like this: E, [2015-07-16T09:23:10.896146 #23308] ERROR -- : app...
In this card we will learn to write code that scales with a large number of database records. We will...
Understand why we use pagination Exercises Create 7500 movies in MovieDB (hint: Doing it in a single transaction is...
Rails comes with grouped_collection_select that appears to be useful, but isn't. As an alternative, consider the flat...
Note: Making a reverse proxy with nginx is much more straightforward. A reverse proxy is a "man in the middle...
When you have an element you want to hide, you can add a ng-show='isOpen' attribute to that element...
You might wonder about this request in your test.log: Started GET "/__identify__" for 127.0.0.1 at 2015-04-29 18:00...
You know that ActiveRecord caches associations so they are not loaded twice for the same object. You also know that...
RSpec 3 has verifying doubles. This breed of mock objects check that any methods being stubbed are present on an...
If you want to rotate text, you can use CSS transforms in somewhat modern browsers to rotate the container element...
Please don't simply copy line number links from Github. The URL usually contains a branch name like master which...
Webfonts are not always available when your JavaScript runs on first page load. Since fonts may affect element sizes, you...