mrmartineau

Stimulus cheatsheet

• Website: https://stimulusjs.org/
• GitHub repo: https://github.com/stimulusjs/stimulus
• Handbook: https://stimulusjs.org/handbook/introduction
• Discourse: https://discourse.stimulusjs.org/

Lifecycle callbacks

• initialize: once, when the controller is first instantiated
• connect: anytime the controller is connected to the DOM

giannisp

After automatically updating Postgres to 10.0 via Homebrew, the pg_ctl start command didn't work.
The error was "The data directory was initialized by PostgreSQL version 9.6, which is not compatible with this version 10.0."

Database files have to be updated before starting the server, here are the steps that had to be followed:

# need to have both 9.6.x and latest 10.0 installed, and keep 10.0 as default
brew unlink postgresql
brew install [email protected]
brew unlink [email protected]
brew link postgresql

alistairewj

Install PostgreSQL 10 on Ubuntu

This is a quick guide to install PostgreSQL 10 - tested on Ubuntu 16.04 but likely can be used for Ubuntu 14.04 and 17.04 as well, with one minor modification detailed below.

(Optional) Uninstall other versions of postgres

To make life simple, remove all other versions of Postgres. Obviously not required, but again, makes life simple. If you have data in your previous version of postgres that you'd like to retain, then this is not recommended. Instead, you'll have to use pg_upgrade or pg_upgradecluster.

mdang

Ruby on Rails Cheatsheet

Architecture

Create a new application

Install the Rails gem if you haven't done so before

KieranP

# A user session class, a simplified mix of the following code samples:
# * https://github.com/blog/1661-modeling-your-app-s-user-session
# * http://www.jonathanleighton.com/articles/2013/revocable-sessions-with-devise/
class Session < ActiveRecord::Base

  # Uncomment if you use Hobo Fields, else add these yourself
  # fields do
  #   session_id :string, :index => true, :unique => true
  #   accessed_at :datetime
  #   user_ip :string

christiannelson

class ApplicationController < ActionController::Base
  include Pundit

  # Verify that controller actions are authorized. Optional, but good.
  after_filter :verify_authorized,  except: :index
  after_filter :verify_policy_scoped, only: :index

  rescue_from Pundit::NotAuthorizedError, with: :user_not_authorized

  private

maxim

In Rails 3

NOTE: This post now lives (and kept up to date) on my blog: http://hakunin.com/rails3-load-paths

If you add a dir directly under app/

Do nothing. All files in this dir are eager loaded in production and lazy loaded in development by default.

If you add a dir under app/something/

vStone

Original header used now:

### File managed with puppet ###
## Served by:        '<%= scope.lookupvar('::servername') %>'
## Module:           '<%= scope.to_hash['module_name'] %>'
## Template source:  'MODULES<%= template_source.gsub(Regexp.new("^#{Puppet::Node::Environment.current[:modulepath].gsub(':','|')}"),"") %>'

Problem: When using puppet apply with relative modulepath, the information can be wrong or messy.

Alternative 1:

damien

module Concerns
  module MessagableWithData

    extend ActiveSupport::Concern

    included do

      Message.class_eval do
        has_many :message_data,
          class_name: MessageData,