SunDi3yansyah

true and false vs. "truthy" and "falsey" (or "falsy") in Ruby, Python, and JavaScript

Many programming languages, including Ruby, have native boolean (true and false) data types. In Ruby they're called true and false. In Python, for example, they're written as True and False. But oftentimes we want to use a non-boolean value (integers, strings, arrays, etc.) in a boolean context (if statement, &&, ||, etc.).

This outlines how this works in Ruby, with some basic examples from Python and JavaScript, too. The idea is much more general than any of these specific languages, though. It's really a question of how the people designing a programming language wants booleans and conditionals to work.

If you want to use or share this material, please see the license file, below.

Update

SunDi3yansyah

Simple automated GIT Deployment using GIT Hooks

Here are the simple steps needed to create a deployment from your lokal GIT repository to a server based on this in-depth tutorial.

How it works

You are developing in a working-copy on your local machine, lets say on the master branch. Most of the time, people would push code to a remote server like github.com or gitlab.com and pull or export it to a production server. Or you use a service like my Deepl.io to act upon a Web-Hook that's triggered that service.

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# See how variables work, and a list of predefined ones:
#  - https://docs.gitlab.com/ce/ci/variables/
variables:
  RAILS_IMAGE: registry.gitlab.com/bryanbraun/gridmaster.io/railsapp:$CI_COMMIT_SHA
  NGINX_IMAGE: registry.gitlab.com/bryanbraun/gridmaster.io/nginx:$CI_COMMIT_SHA
  DEPLOY_TAG: $CI_COMMIT_SHA

cache:
  paths:
  - vendor/ruby

SunDi3yansyah

Make /robots.txt aware of the Rails environment

You probably don't want Google crawling your development staging app. Here's how to fix that.

$ mv public/robots.txt config/robots.production.txt
$ cp config/robots.production.txt config/robots.development.txt

Now edit config/routes.rb to add a route for /robots.txt, and add the controller code.

SunDi3yansyah

Realtime Notifications with ActionCable

In this episode we're going to be adding realtime notifications into your app using ActionCable. We've talked about notifications a few times in the past and we used AJAX polling for that. 95% of the time, polling is the solution that would be recommended for it.

But if you're looking for a good introduction into ActionCable then this is a decent one because we're only really using it for one way from the server side to the client side.

Getting started

So to get started we're starting with an app that has Bootstrap installed and then we created a Main controller with an index view which is where we will list our Notifications as for this example.

Before we generate our channels let's install a few things

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Setup

Replace IRB with Pry (in your Gemfile) and Byebug with pry-byebug.

gem 'pry-rails', group: [:development, :test]
gem 'pry-byebug', group: [:development, :test]

Using PRY

SunDi3yansyah

Subdomaining Localhost with Rails 5

I've been following this blog post on how to set up an api-only Rails 5 application. One of the sections talks about creating a subdomain for your api

Rails.application.routes.draw do
  constraints subdomain: "api" do
    scope module: "api" do

SunDi3yansyah

# Thanks to tenderlove on Peepcode play by play

require 'digest/md5'

def fetch username
  records = JSON.parse get username
  records.each do |hash|
    checksum = Digest::MD5.hexdigest Marshal.dump(hash)
    hash['checksum'] = checksum
  end

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#!/bin/zsh -i
# if you're using ZSH, change the shebang above to "#!/bin/zsh -i"

eval "$(rbenv init -)"

if [ ${#} -ne 2 ]; then
  echo >&2 Usage: $(basename ${0}) old-version new-version
  exit 1
fi

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class ActiveRecord::Base
  
  def self.import!(record_list)
    raise ArgumentError "record_list not an Array of Hashes" unless record_list.is_a?(Array) && record_list.all? {|rec| rec.is_a? Hash }
    return record_list if record_list.empty?

    (1..record_list.count).step(1000).each do |start|
      key_list, value_list = convert_record_list(record_list[start-1..start+999])
      sql = "INSERT INTO #{self.table_name} (#{key_list.join(", ")}) VALUES #{value_list.map {|rec| "(#{rec.join(", ")})" }.join(" ,")}"
      self.connection.insert_sql(sql)