MaherSaif

# Channel
class CommentsChannel < ApplicationCable::Channel
  def self.broadcast_comment(comment)
    broadcast_to comment.message, comment: CommentsController.render(
      partial: 'comments/comment', locals: { comment: comment }
    )
  end

  def follow(data)
    stop_all_streams

MaherSaif

Indicators (by Category)

Candles

1. 2crows
2. 3blackcrows
3. 3inside
4. 3linestrike
5. 3outside
6. 3starsinsouth

MaherSaif

require 'tempfile'

# The DSL class. The render method simply takes a block, then executes the block in the scope of the DSL class. You can see
# a use of it in the next file.

module Keyd
  class DSL
    def self.render(&block)
      d = new
      d.instance_exec(&block)

MaherSaif

-- based on https://www.crunchydata.com/blog/understanding-postgres-iops

SELECT
    interval '1 millisecond' * total_exec_time AS "Total Exec. Time",
    to_char (
        (total_exec_time / sum(total_exec_time) OVER ()) * 100,
        'FM90D0'
    ) || '%' AS "Proportional Exec. Time",
    to_char (calls, 'FM999G999G999G990') AS "Calls",
    interval '1 millisecond' * (blk_read_time + blk_write_time) AS "Time Spent on IO",

MaherSaif

At the time of writing this article, PostgreSQL 17 is nearly out. On September 5th, the first release candidate was published. The final release is expected on September 26th, but we can already explain why we’ve been eagerly awaiting this release since 1 year.

At Lifen, we’ve loved Rails from the beginning. We have several Rails applications, each with different scopes and teams, all using PostgreSQL as the main database. Some of these applications handle a significant amount of traffic, and their databases need to be properly monitored. This is done by the infrastructure team and the developers themselves using PgAnalyze, Grafana and sometimes AWS console with "Performance Insight".

More than a year ago, we started monitoring the 95th and 99th percentile response times (p95, p99) on an endpoint that was experiencing timeouts. These p99 times were important because they involved a client with significantly mo

MaherSaif

-- Carefull setup script is slow
-- SETUP SCRIPT :: START --
DROP TABLE IF EXISTS docs;
CREATE TABLE docs (
  id SERIAL PRIMARY KEY,
  type varchar(40) DEFAULT 'pdf' NOT NULL,
  status varchar(40) NOT NULL,
  sender_reference varchar(40) NOT NULL,
  sent_at TIMESTAMPTZ,

MaherSaif

[
	{
		"context": "Editor",
		"bindings": {
			"alt-up": "editor::SelectLargerSyntaxNode",
			"alt-down": "editor::SelectSmallerSyntaxNode",
			"ctrl-cmd-up": "editor::MoveLineUp",
			"ctrl-cmd-down": "editor::MoveLineDown"
		}
	}

MaherSaif

class FuzzyIndex
  def initialize
    @index = Hash.new { |h, k| h[k] = Set.new }
  end
  
  def []=(key, value)
    trigrams(key).each { @index[it] << [key, value] }
  end
  
  def [](query)

MaherSaif

Browser Based

1. Web Wormhole https://webwormhole.io/ https://github.com/saljam/webwormhole
2. ToffeeShare https://toffeeshare.com/
3. FilePizza https://file.pizza/
4. ShareDrop sharedrop.io https://github.com/szimek/sharedrop (SOLD, not recommended, use one of the forks)
   1. A clone SnapDrop snapdrop.net https://github.com/RobinLinus/snapdrop (SOLD, not recommended, use one of the forks)
      1. A fork PairDrop https://pairdrop.net/ https://github.com/schlagmichdoch/pairdrop
5. Instant.io https://instant.io/
6. FileTC https://file.tc/

MaherSaif

• You MUST NOT try and generate a Rails app from scratch on your own by generating each file. For a NEW app you MUST use rails new first to generate all of the boilerplate files necessary.
• Create an app in the current directory with rails new .
• Use Tailwind CSS for styling. Use --css tailwind as an option on the rails new call to do this automatically.
• Use Ruby 3.2+ and Rails 8.0+ practices.
• Use the default Minitest approach for testing, do not use RSpec.
• Default to using SQLite in development. rails new will do this automatically but take care if you write any custom SQL that it is SQLite compatible.
• An app can be built with a devcontainer such as rails new myapp --devcontainer but only do this if requested directly.
• Rails apps have a lot of directories to consider, such as app, config, db, etc.
• Adhere to MVC conventions: singular model names (e.g., Product) map to plural tables (products); controllers are plural.
• Guard against incapable browsers accessing controllers with `allo