zakariaf

Rails 7 new features. Before and After

• Add ComparisonValidator
• PostgreSQL generated columns
• PostgreSQL custom enum types
• Add tracking of belongs_to association
• association_previously_changed? method
• Add invert_where method
• Add associated method
• Add missing method
• Active Record Encryption

ryanb

class CreateNodes < ActiveRecord::Migration[6.0]
  def change
    create_table :nodes do |t|
    end
    
    create_table :node_edges do |t|
      t.integer :parent_id, null: false
      t.integer :child_id, null: false
    end
    

ProGM

Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

Tables

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

Table alias

MuhsinFatih

I am assuming you are here because like me, you installed a bazillion different python interpreters on mac and the whole thing is a spagetti. Today, I finally fixed my python installation. Whatever I install for python2 or python3 using pip JUST.WORKS.. My god! finally.

What the hell?

Here is what I had messed up, which you also probably did:

• I had too many different python interpreters
• Too many different symlinks which I lost track of
• almost no package I installed with pip worked without a headache
• any attempt to fix using online resources made it worse.

janko

source "https://rubygems.org"

gem "roda"
gem "http", "~> 3.3"
gem "rest-client"
gem "httparty"

ssaunier

Rails 5.1 introduces a new way of coding JavaScript. You would use yarn, webpack and a new folder, app/javascript.

Setup

If you want to stick with the "old" way (before 5.1) and use the asset pipeline, you need to do this:

# Gemfile

gem 'sprockets', '>= 3.0.0'

wojteklu

Code is clean if it can be understood easily – by everyone on the team. Clean code can be read and enhanced by a developer other than its original author. With understandability comes readability, changeability, extensibility and maintainability.

---

General rules

1. Follow standard conventions.
2. Keep it simple stupid. Simpler is always better. Reduce complexity as much as possible.
3. Boy scout rule. Leave the campground cleaner than you found it.
4. Always find root cause. Always look for the root cause of a problem.

Design rules

tristang

require 'benchmark'
require 'ostruct'

REP = 1000000

User = Struct.new(:name, :age)

USER = "User".freeze
AGE = 21
HASH = {:name => USER, :age => AGE}.freeze

ssaunier

namespace :db do
  desc "Backs up heroku database and restores it locally."
  task import_from_heroku: [ :environment, :create ] do
    HEROKU_APP_NAME = nil # Change this if app name is not picked up by `heroku` git remote.

    c = Rails.configuration.database_configuration[Rails.env]
    heroku_app_flag = HEROKU_APP_NAME ? " --app #{HEROKU_APP_NAME}" : nil
    Bundler.with_clean_env do
      puts "[1/4] Capturing backup on Heroku"
      `heroku pg:backups capture DATABASE_URL#{heroku_app_flag}`

myusuf3

To remove a submodule you need to:

• Delete the relevant section from the .gitmodules file.
• Stage the .gitmodules changes git add .gitmodules
• Delete the relevant section from .git/config.
• Run git rm --cached path_to_submodule (no trailing slash).
• Run rm -rf .git/modules/path_to_submodule (no trailing slash).
• Commit git commit -m "Removed submodule "
• Delete the now untracked submodule files rm -rf path_to_submodule