The postMessage API is an alternative to JSONP, XHR with CORS headers and other methods enabling sending data between origins...
There are various ways to run external commands from within Ruby, but the most powerful ones are Open3.capture3 and Open3.popen3...
Occasionally, you have to talk to APIs via HTTPS that use a custom certificate or a misconfigured certificate chain (like...
/home/.../ruby/gems/2.1.0/gems/bundler-1.14.3/lib/bundler/rubygems_ext.rb:45:in `full_gem_path': uninitialized constant Bundler::Plugin::API::Source (NameError) Solution: Upgrade Rubygems beyond 2.6.9...
Sometimes huge refactorings or refactoring of core concepts of your application are necessary for being able to meet new requirements...
Exercise 1: XML On the start page of your Movie DB, show the title of a random movie that is...
Understand how we're dealing with exception notifications. Integrate exception notification into your MovieDB. Use your personal e-mail as...
So you're getting this failure when running bundle install on an older project: Your Gemfile.lock is corrupt. The following...
When testing your command line application with Aruba, you might need to stub out other binaries you don't want...
Rails 5 migration classes look like this now: class CreateUsers < ActiveRecord::Migration[5.0] Mind the [5.0] at the end.
ActiveSupport::Notifications provides an instrumentation API for Ruby. It is used throughout rails to publish instrumentation events that include information...
Promises are the new way™ to express "Do this, and once you're done, do that". In contrast to callbacks...
Resources Rails Guide: Internationalization API Guide to localizing a Rails application Locale-aware helpers in ActionView::Helpers::NumberHelper
When dealing with time zones in Rails, there is one key fact to keep in mind: Rails has configurable time...
You can use JavaScript to get or set cookie values on the client. Using the vanilla JavaScript API
To upload a file via AJAX (e.g. from an ) you need to wrap your params in a FormData object.
If you are on a Linux shell and want to open a file with whatever default application is configured for...
To install gems Bundler needs to be able to talk to https://api.rubygems.org. If you are behind a proxy you...
MutationObserver provides developers a way to react to changes in a DOM. Any: insertion, deletion, attribute change – anything. Quickstart: https://...
With "attaching an event handler once" you possibly mean one of these two things: Register a function for an event...
Note This card does not reflect the current state of lazy loading technologies. The native lazy attribute could be used...
While you usually do not need a Content-Type on GET request (which have a blank body), an external API...
Redactor is yet another WYSIWYG editor. It definitely has its weak points, but I want to point out that it...
What is a Cookie? Google it if you do not know. How are cookies transferred between your browser and...