danielfone

module TestReflection
  module_function

  def recursive_parent_associations(klass, list=Set.new)
    assocs = klass.reflect_on_all_associations(:belongs_to) + klass.reflect_on_all_associations(:has_one)
    assocs.each do |a|
      next if list.include?(a.name)
      list << a.name
      recursive_parent_associations(a.klass, list)
    end

danielfone

def nest(rows, *attributes)
  rows.each_with_object({}) do |row, hash|
    # e.g. row        = { colour: "red",   size: "small", shape: "cube", count: 4 }
    #      attributes = [:colour, :size, :shape]

    # split out the last key from the rest
    # row.values_at(:colour, :size, :shape) => ["red", "small", "cube"]
    *rest, last = *row.values_at(*attributes)                       # last = "cube"
                                                                    # rest = ["small", "red"]

danielfone

require 'active_model'

#
# The reusable validator
#
class PermittedKeysValidator < ActiveModel::EachValidator

  def check_validity!
    raise ArgumentError, "you must supply permitted keys" unless permitted_keys.present?
  end

danielfone

$ ruby -v
ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-darwin15]
$ pry
[1] pry(main)> class Animal
[1] pry(main)*   def noise
[1] pry(main)*     "bump"
[1] pry(main)*   end  
[1] pry(main)* end  
=> :noise
[2] pry(main)> class Dog < Animal

danielfone

What temperature will the 2016 Christchurch Marathon be?

The Christchurch marathon is being held on 5th June this year, and the race starts at 8:30 am. Since I plan to run it, I wanted to know what the temperature was likely to be. Fortunately, NIWA publishes the National Climate Database online for free, and with a few quick queries later, I had all the data I needed. Helpfully, the database exposes the 9 a.m. air temperatures from the "Screen Observations" of its stations (amongst many, many other metrics) which is close enough to the marathon start time (of course, we'd expect it to warm up over the course of the race, but this is a good start). Also helpfully, there is a station in Hagley Park around which the marathon is run.

The dataset provided every 9 a.m. reading going back to 1972, which I subsequently filtered to readings from the 5th Jun ± 4 days. A little excel-fu gives us our required stats and a pretty graph.

I am no

danielfone

Keybase proof

I hereby claim:

• I am danielfone on github.
• I am danielfone (https://keybase.io/danielfone) on keybase.
• I have a public key whose fingerprint is F30F 53FA 4E66 F2A1 97D4 7124 B8D3 AD7D 56AD 919D

To claim this, I am signing this object:

danielfone

    def post_process(*style_args) #:nodoc:
      return if @queued_for_write[:original].nil?

      catch :validation_failed do
        instance.run_paperclip_callbacks(:post_process) do
          instance.run_paperclip_callbacks(:"#{name}_post_process") do
            throw :validation_failed if @options[:check_validity_before_processing] && instance.errors.any?
            post_process_styles(*style_args)
          end
        end

danielfone

Small Arrays: (80 + 40)
Calculating -------------------------------------
           b & a | a    24.860k i/100ms
             sort_by    27.909k i/100ms
                 set     7.622k i/100ms
-------------------------------------------------
           b & a | a    339.055k (± 3.3%) i/s -      1.715M
             sort_by    393.757k (± 2.9%) i/s -      1.982M
                 set     84.387k (± 2.1%) i/s -    426.832k

danielfone

#! /usr/bin/env ruby

require 'active_record' # 4.2.3
require 'paperclip' # 4.3.0

ActiveRecord::Migration.verbose = false
ActiveRecord::Base.establish_connection(:adapter => "sqlite3", :database => ":memory:")
ActiveRecord::Base.raise_in_transactional_callbacks = true
ActiveRecord::Schema.define(:version => 1) do
  create_table :widgets, force: true do |t|

danielfone

def changes
  @changes ||= created_changes + updated_changes + deleted_changes
end

def created_changes
  changes_for created_fields, :created
end

def updated_changes
  changes_for updated_fields, :updated