1  
   2  # THIS FILE CONTAINS INTERESTING SNIPPETS OF RUBY/RAILS
   3  # in order to accelerate learning and find forgotten things
   4  #  
   5  #  Key shortcuts!
   6  #  ctrl+shift+v  controller/view!
   7  #  ctrl+k  find next word
   8  #  ctrl+m maximize editor
   9  #  
  10  # 
  11  # 
  12  #   
  13  BAD
  14  -----------------------
  15  model files do not contain the classes field information 
  16  instead this is stored in different 'migration' files
  17  create_table "periods" do |t|
  18      t.column "target_id", :integer
  19      t.column "target_type", :string
  20      t.column "start_at", :datetime
  21      t.column "end_at", :datetime
  22      t.column "wholeday", :boolean
  23      t.column "wholeweek", :boolean
  24      t.column "allweeks", :boolean
  25    end
  26   NO inbuild multi dimensional arrays
  27  DANGER!!!!!
  28  and is not && !!!!!!!!!!!!!!!!!!!!!!!!
  29  return x==7 and y==8  => void value expression!!!
  30  return x==7 && y==8  !!!
  31  nr==0 (evaluates string.nil? !!!!!!!  "0"==0 -> false!!!!)
  32  nr.to_i==0 !!
  33  
  34  #ANNOYANCES:
  35  + operator for string is really baad :
  36  cannot convert nil into String !!! 
  37  puts "teacher "+ @lesson.teacher
  38   "last saved : "+ DateTime.now.to_s  #to_s !!! neccessary!!!!!!! (and ugly)
  39  "nr"+rand(10).to_s#!!!
  40  
  41  Language buggy: (see http://public.transcraft.co.uk/blog/index.html)
  42  ActionController::RoutingError (Recognition failed for "/images/btnbg.gif"):
  43  
  44  helpers are only for views!! (ApplicationController is what you need)
  45  
  46  @links = Link.find_by_sql [
  47  "SELECT * from links where link like '"+ @a +"%' order by id asc"]
  48    #endwith startwith
  49  s = "Hello, world"
  50  /^Hello/.match( s ) 	>> true
  51  /world$/.match( s ) 		>> true
  52    
  53   
  54  <!--bad philosopy : evaluation inside html comments?
  55  <%#= datetime_select 'lesson', 'end_at'  %></p>-->
  56    
  57    -------------------------------------
  58  Good
  59  ********************
  60  
  61  class.byname:
  62  
  63    alle= eval(type+".find(:all)")
  64    Object.const_get("Array")
  65  
  66  # default values
  67  def initialize(definitions=[], word = nil)       
  68        @definitions = definitions
  69        @word = word
  70      end
  71  
  72  
  73  rake db_schema_dump !!! instead of writing the migration files yourself
  74  
  75  rake --help
  76  rake migrate VERSION=n  #runs from 0 to n !!!!!!!!!!!
  77  
  78  
  79  Customer.find_all [ "company = ?", company ]
  80  und wenn man eine LIKE '%xx%' Abfrage erstellen möchte:
  81  Customer.find_all [ " company LIKE ? ", '%#{company}%' ]
  82  
  83  string arrays:
  84  x= %w(Montag Dienstag) is short for 
  85  y= ["Montag" ,"Dienstag"]
  86  
  87  <%= sortable_element('listOrTableId' , :url => { :action => 'move' }) #, :update => 'test-id',:tag => 'tr',  :complete => visual_effect(:highlight, q.id))%>
  88  
  89  <%= observe_field(:search,
  90  	:frequency => 0.5,
  91  	:update => :results,
  92  	:url => { :action => :search }, 
  93  	:loading => "Element.show('indicator_gif_id')",
  94  	:complete => "Element.hide('indicator_gif_id')") 
  95  	%>
  96  
  97  
  98  /// HOW TOs  (mixed with 'good')
  99  
 100  global functions !
 101  put them in application.rb (ApplicationController)
 102  
 103  
 104  
 105  
 106  Regular expressions
 107  #substitute patterns (m=LineBreaks u=Unicode i=IgnoreCase)
 108  a=a.gsub(/<img.*?>/mui, "")  # yeah right nice naming, suckers! 
 109  
 110  send_file or send http response data
 111    send_data @person.picture, :filename => @person.filename, :type => "image/jpeg", :disposition => "inline"
 112  
 113  require 'net/ftp'
 114   ftp = Net::FTP.new('ftp.netlab.co.jp') 
 115   ftp.login files = ftp.chdir('pub/lang/ruby/contrib')
 116    files = ftp.list('n*') 
 117    ftp.getbinaryfile('nif.rb-0.91.gz', 'nif.gz', 1024)
 118     ftp.close
 119  
 120  #reflection : 
 121  list.class.reflect_on_all_associations
 122  
 123  >>>>>>>regex<<<<<<<<
 124  // greedy !!!!
 125  puts "a[bcb]d[bebb]rerberb]w[bsdaeb]ega".scan(/\[b(.*)b/).inspect
 126  =>cb]d[bebb]rerberb]w[bsdae
 127  
 128  // .*? not greedy ++
 129  puts "a[bcb]d[bebb]rerberb]w[bsdaeb]egab".scan(/\[b(.*?)b/).inspect
 130  => [["c"], ["e"], ["sdae"]]
 131  
 132  #debug over ssh:
 133  #ruby breakpointer [options] [server uri]
 134  #ruby script/generate scaffold x // model + view!
 135  #http://www.rubycentral.com/book/tut_modules.html modules
 136  
 137  
 138    require 'net/http'
 139      require 'uri'
 140      img='http://www.macdesktops.com/?res=TRUE&category=35'
 141        html=Net::HTTP.get URI.parse(img)
 142  
 143  #switch cases
 144   def search
 145      @results = Search.find(params[:query])
 146      case @results
 147        when 0 then render :action=> "no_results"
 148        when 1 then render :action=> "show"
 149        when 2..10 then render :action=> "show_many"
 150      end
 151    end
 152    
 153  
 154  module Action
 155    VERY_BAD = 0
 156    BAD      = 1
 157    def Action.sin(badness)
 158      # ...
 159    end
 160  end
 161  
 162  require "trig"
 163  require "action"
 164  ##########
 165  MIXINS
 166  module Debug
 167    def whoAmI?
 168      "#{self.type.name} (\##{self.id}): #{self.to_s}"
 169    end
 170  end
 171  class Phonograph
 172    include Debug
 173    # ...
 174  end
 175  class EightTrack
 176    include Debug
 177    # ...
 178  end
 179  ph = Phonograph.new("West End Blues")
 180  et = EightTrack.new("Surrealistic Pillow")
 181  #ph.whoAmI? 	» 	"Phonograph (#537766170): West End Blues"
 182  #et.whoAmI? 	» 	"EightTrack (#537765860): Surrealistic Pillow"
 183  ##########################33
 184  time=5.minutes + 30.seconds ## cool !!!!!!
 185  
 186  5.times do |i|
 187     File.open("temp.rb","w") { |f|
 188       f.puts "module Temp\ndef Temp.var() #{i}; end\nend"
 189     }
 190     load "temp.rb"
 191     puts Temp.var
 192   end
 193   ################
 194  print "Enter your name: "
 195  name = gets
 196  #################
 197  
 198  Argumentlisten variabler Länge
 199  Was aber, wenn Sie eine variable Anzahl von Argumenten übergeben wollen oder mehrere Argumente mit einem einzigen Parameter auffangen wollen? Wenn Sie einen Stern vor den Namen des Parameters nach den ``normalen'' Parametern setzen, wird genau das gemacht.
 200  def varargs(arg1, *rest)
 201    "Got #{arg1} and #{rest.join(', ')}"
 202  end
 203  
 204  
 205  y = Trig.sin(Trig::PI/4)
 206  wrongdoing = Action.sin(Action::VERY_BAD)
 207  # setup:
 208  # rails <appname>
 209  # ruby script\generate scaffold survey #!!  does the following too:
 210  # ruby script\generate controller survey
 211  # ruby script\generate model survey
 212  #backward if
 213  #def isanum=true
 214  puts "It's not a number" if isanum.nil?
 215  
 216  #$! variable!!
 217   rescue ScriptError, StandardError
 218      printf "ERR: %s\n", $! || 'exception raised'
 219  #eval
 220  eval(line).inspect
 221  
 222  #regexp matching   & no brackets
 223  if a =~ /^[-+]?\d+$/;
 224  	puts "It's a number that may indicate positive or negative"
 225  end
 226  
 227  Does anyone know how to get an ID back, instead of a String?
 228  @doctor = Doctor.find_by_name(params[:doctor][:name])
 229  params[:parent][:doctor] = @doctor
 230  
 231  #what is that?   yml intralanguage :(
 232  #  database: verwurzelt_de_development
 233  #  <<: *login
 234  
 235  
 236  #Simplemost file IO:
 237  IO.foreach("testfile") { |line| puts line }
 238  
 239  arr = IO.readlines("testfile")
 240  
 241  #Simple socket
 242  require 'socket'
 243  client = TCPSocket.open('localhost', 'finger')
 244  client.send("oracle\n", 0)    # 0 means standard packet
 245  puts client.readlines
 246  client.close
 247  
 248  #HTTP
 249  require 'net/http'
 250  h = Net::HTTP.new('www.pragmaticprogrammer.com', 80)
 251  resp, data = h.get('/index.html', nil)
 252  if resp.message == "OK"
 253    data.scan(/<img src="(.*?)"/) { |x| puts x }
 254  end #get images!
 255  
 256  #error handling:
 257    f = File.open("testfile")
 258  begin
 259    f.each_line {|line| puts "Got #{line.dump}" }
 260    # .. process
 261    raise ArgumentError, "Name too big", caller
 262  rescue ArgumentError
 263  #rescue 
 264    # .. handle error
 265  else
 266    puts "Congratulations-- no errors!"
 267  ensure
 268    f.close unless f.nil?
 269  end
 270  #############
 271   # SICK : two mechanisms!!!
 272   def promptAndGet(prompt)
 273    print prompt
 274    res = readline.chomp
 275    throw :quitRequested if res == "!"
 276    return res
 277  end
 278  
 279  catch :quitRequested do
 280    name = promptAndGet("Name: ")
 281    age  = promptAndGet("Age:  ")
 282    sex  = promptAndGet("Sex:  ")
 283    # ..
 284    # process information
 285  end
 286  #############
 287    
 288  require 'breakpoint'
 289  Thread.new do
 290  loop do
 291  begin
 292  breakpoint
 293  rescue Exception
 294  end
 295  end
 296  end
 297  
 298  
 299  <script type="text/javascript" language="javascript" charset="utf-8">
 300  // <![CDATA[
 301    Sortable.create('sortlist',{ghosting:false,constraint:false,hoverclass:'over',
 302      //onUpdate:function(sortable){alert(Sortable.serialize(sortable))},
 303      onChange:function(element){
 304  	var	data=    Sortable.serialize(element.parentNode);
 305  	var url="<%=url_for :controller=>'question',:action=>'move'%>";
 306  	new Ajax.Request(url,{parameters:data});
 307      }
 308    });
 309  // ]]>
 310  </script>
 311