George Opritescu International

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

Rails 5.2 with webpacker, bootstrap, stimulus starter

This gist will collects all issues we solved with Rails 5.2 and Webpacker

Create Project

# Last few parameters(--skip-* part) is only my habbit not actully required
$ rails new <project_name> --webpack=stimulus --database=postgresql --skip-coffee --skip-test

	#!/bin/bash
	# Script to update a firewall rule in a Hetzner Firewall with your current IP address.
	# Good if you would like to restrict SSH access only for your current IP address (secure).

	#################
	# WARNING: This script will overwrite all rules in the firewall rules, so make sure you
	# added all the required rules.
	# I use a separate firewall rule just for SSH access.
	#################

	-- The goal of this script is to trim messages that have been processed by
	-- all extant groups from the a given Redis stream. It returns the number
	-- of messages that were deleted from the stream, if any. I make no
	-- guarantees about its performance, particularly if the stream is large
	-- and not fully processed (so a simple XTRIM isn't possible).

	-- First off, bail out early if the stream doesn't exist.
	if redis.call("EXISTS", KEYS[1]) == 0 then
	return false
	end

	## Context + metadata
	shared_context 'Logged as a user', role: true do
	let(:user) { \|example\| create :user, example.metadata[:role] }
	before { login_as user }
	end

	scenario "Login as a client", role: :client
	scenario "Login as a customer", role: :customer
	scenario "Login as an admin", role: :admin

	wget https://storage.googleapis.com/golang/go1.10.1.linux-armv6l.tar.gz
	sudo tar -C /usr/local -xvf go1.10.1.linux-armv6l.tar.gz
	cat >> ~/.bashrc << 'EOF'
	export GOPATH=$HOME/go
	export PATH=/usr/local/go/bin:$PATH:$GOPATH/bin
	EOF
	source ~/.bashrc

	defmodule MyApp.Auth do
	import Comeonin.Bcrypt, only: [checkpw: 2, dummy_checkpw: 0]

	alias MyApp.Accounts.User
	alias MyApp.Repo

	def login(conn, user) do
	conn
	\|> Guardian.Plug.sign_in(user)
	end

	# http://adventofcode.com/2017/day/1

	defmodule Day1 do
	def sum1(digits), do:
	digits
	\|> Stream.concat(Enum.take(digits, 1))
	\|> Stream.chunk_every(2, 1, :discard)
	\|> Stream.filter(&match?([el, el], &1))
	\|> Stream.map(&hd(&1))
	\|> Enum.sum()

	1. Change rails version in Gemfile
	> gem 'rails', '~> 5.1', '>= 5.1.4'

	2. Remove Gemfile.lock
	> git rm Gemfile.lock

	3. Run bundle install command
	> bundle install --jobs=5

	4. Run rails' app update to apply changes to app

	// how to run:
	// go run mqtt.go tcp://iot.eclipse.org:1883 /topic/name
	package main

	import (
	"os"

	mqtt "github.com/eclipse/paho.mqtt.golang"
	"github.com/gizak/termui"
	)