iNecas

# getting first item of array or empty hash, when empty:

# A) Without documentation:
	def get_first_item_from_array(array)
		unless array.blank?
			array.each do |single|
				return single
			end
		end
		return {}

iNecas

# wrong
["9.13.3", "9.3.2", "10.1.1", "9.3.5"].sort 
# => ["10.1.1", "9.13.3", "9.3.2", "9.3.5"]

# right
["9.13.3", "9.3.2", "10.1.1", "9.3.5"].sort_by{|version| version.scan(/\d+/).map(&:to_i)}
# => ["9.3.2", "9.3.5", "9.13.3", "10.1.1"] 

iNecas

hash = Hash.new("")              # => {}
hash[1] << "Hello"               # => "Hello"
hash[2]                          # => "Hello"
hash = Hash.new{|h,k| h[k] = ""} # => {}
hash[1] << "Hello"               # => "Hello"
hash[2]                          # => ""

iNecas

pscs = {
   ["Brno", "Hradecká"] => [61200,62100],
   ["Brno", "Merhautova"] => [61300,61400],
   ["Brno", "Nezamyslova"] => [61500,63600],
}

pscs.each do |(city, street), street_pscs|
  puts "#{street} in #{city} has following PSCs: #{street_pscs.join(", ")}"
end

iNecas

<?php

/** Convention foreign keys: plugin for Adminer
* Links for foreign keys by convention user_id => users.id. Useful for Ruby On Rails like standard schema conventions.
* @author Ivan Nečas, @inecas
* @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
* @license http://www.gnu.org/licenses/gpl-2.0.html GNU General Public License, version 2 (one or other)
*/
class ConventionForeignKeys {

iNecas

string = "<div>ruby</div><div>string</div><div>methods</div>"

# == splitting with regexp

string.split(/<.*?>/) 
# => ["", "ruby", "", "string", "", "methods"]

# == and keeping separator in the result

string.split(/(<.*?>)/) 

iNecas

comps = ["PC", "MAC", "PC", "PC", "LINUX", "MAC", "DIDAKTIK"]

duplicities = comps.group_by{|x| x.first}.find_all{|k,v| v.size > 1}.map{|x| x.first}

duplicities # => ["MAC","PC"]

iNecas

# Usage:
#
#  Then directory "tmp/sample" should have the following tree:
#      """
#        monday
#        | beer.rb
#        tuesday
#        | vodka.php
#        | wine.rb
#        wednesday

iNecas

# Why it is not a good idea to rescue without explicit exception type?
# Because:
#
#  begin
#   "..."
#  rescue
#  end
#
# Handles only StandardError descendants (no Excpetion descendants catched)

iNecas

    def get_distribution env, id
      self.repos(env).map do |repo|
        repo.distributions.find_all {|d| d.id == id }
      end
    end