PostgreSQL's array data type is pretty useful, but manipulating values of arrays can be awkward because of its syntax...
Our applications not only need to be functional, they need to be fast. But, to quote Donald Knuth, premature optimization...
What is a Cookie? Google it if you do not know. How are cookies transferred between your browser and...
Some tasks in a web application are better not done live when a user request a page, but in the...
When working with PostgreSQL, you can use pgAdmin as a GUI. While you can do most things just like on...
Understand how nested attributes appear in the params. See how the Rails form helpers encode the names of nested...
Many of our clients can't or don't want to design their user interfaces. In the absence of a...
For each movie in MovieDB, we want to track which other movie it was inspired by. For...
It smells. Rethink your code design. Code example with makandra/has_defaults: class Post < ActiveRecord::Base has_defaults tags: [] # field in db...
Built-in matchers Get an overview of all the matchers that are built into RSpec. Play with some of...
If you need a postgresql extension for your database it isn't a good idea to give your applications database...
Read the Rails Guide about Active Record migrations Understand why we never use models in migrations. Checkout the repository...
In a web application you often need to move data between the client (HTML, Javascript) and the server (Ruby, Rails...
Use form models to handle this problem Or soften the validation to validates_presence_of :parent
Web security basics Einführung in die Web Security 🇩🇪 provides essentials for the topic of this card. Read following chapters:
Authentication is all about being able to verify the identity of a user in the context of our application.
In tests, it is sometimes useful to create records with specific ids. On PostgreSQL this can cause problems: Usually, PostgreSQL...
Read (or re-read) the following chapters from our book Growing Rails Applications in Practice (it’s in our...
A common task in web applications is to add client-side JavaScript behavior to existing HTML elements.
The migration DSL now supports adding and removing foreign keys. They are dumped to schema.rb as well. At this time...
iPads will not trigger click events for all elements. You can fix that, but you don't want to know...
Large projects usually have large test suites that can run for a long time. This can be annoying as running...
Get an idea of the varying support for HTML/CSS/JavaScript features in different browsers like Chrome, Firefox, Internet Explorer, Edge...
Action Mailer Basics and Previews Chapter "Task H1: Sending Confirmation Emails" from Agile Web Development with Rails (in our...