timuruski

require 'active_support/core_ext/array/extract_options'

# This makes it easy to tag all errors generated by the app with the
# CustomError module so they can be handled specifically. The NestedException
# module is also included so that it can wrap errors from other parts
# of the system.
module CustomError
  # Public: Builds a new Error class and optionally includes the
  # NestedException module.
  #

timuruski

# In your ~/.gitconfig
[alias]
  deploy = "!source ~/.githelpers && deploy_git_log"


# Add to or create ~/.githelpers and chmod +x
#!/bin/bash
deploy_git_log() {
  ref=${1:-'master'}

timuruski

This is a callback object for copying denormalized associations from some sort of parent or key record into a child on initialize.

Consider this extremely simple multi-tenant blog application. We have many sites, and each site has a list of users. For our super-admin system we want some of these associations denormalized so has_many_through isn't quite what we need.

class Site < ActiveRecord::Base

timuruski

require 'csv'

class CSVParser
  FileEncodingProblem = Class.new(RuntimeError)
  CSVParsingProblem = Class.new(RuntimeError)

  def initialize(filepath)
    @filepath = filepath
    @errors = []
  end

stevedev

ActiveModel::Filters

Overview

Provide a ActiveModel::Validations style set of helpers for models to add input filters that work on all dirty fields before validation.

The point of this is I have a project that requires some data consistency and right now that's all ad-hoc and messy. I need a better way to quickly ensure that a username is lower case, things are trimmed properly before stored in the db, etc. Right now that's all done manually on the controller or model, or not at all.

Example Usage

steveklabnik

set nocompatible      " We're running Vim, not Vi!

set guifont=Bitstream\ Vera\ Sans\ Mono:h24

let g:molokai_original = 1
colorscheme molokai

syntax on             " Enable syntax highlighting
filetype on           " Enable filetype detection
filetype indent on    " Enable filetype-specific indenting

timuruski

class Merchant < ActiveRecord::Base
  has_one :store

  # Returns a constantized namespace for the merchant.
  # Not sure how to handle the nil case, if it can exist.
  #
  # Here we use GeneralMerchant, but it can be anything.
  def namespace
    read_attribute(:namespace).constantize rescue GeneralMerchant
  end

practicingruby

Models, Roles, Decorators, and Interactions

A modest alternative to DCI that might be worth further thought

One of the problems with advancing the discussion on DCI is that we lack a comparable alternative pattern that has the same goals, but favors a low ceremony approach. The closest thing we have to that is Rails concerns, but they are more like distant relatives of the DCI concepts rather than first cousins, and that makes comparisions between the two approaches not especially fruitful.

I am considering the idea of experimenting with my own paradigm that captures the intent and purity of DCI, but with the convenience of concerns. Please note that this is just the starting point of a conversation, it is NOT a promise of comercially available cold fusion or a cure for cancer. It's just a gist with an idea on it I'd like to hear your thoughts on.

What if we had a top-level topology that was split into Models, **Rol

andkerosine

$stack, $draws = [], {}

def method_missing *args
  return if args[0][/^to_/]
  $stack << args.map { |a| a or $stack.pop }
  $draws[$stack.pop(2)[0][0]] = args[1] if args[0] == :<
end

class Array
  def +@

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs