DZone Snippets: Ovhaag's Code Snippets

convert between characters and values

ovhaag (Oliver Haag) — Fri, 18 May 2007 15:34:49 GMT

// character to ASCII value: use ?



?a     # => 97

?\n    # => 10

// string to integer: use []



'a'[0]        # => 97

'hallo'[1]    # => 97

// integer / number to character: use .chr



97.chr     # => "a"

10.chr     # => "\n"

//more info: "Ruby Cookbook", O'Reilly

radio button, boolean selection

ovhaag (Oliver Haag) — Thu, 22 Feb 2007 13:43:52 GMT

// radio buttons generated with form helper
// selection by boolean
// attention interger numbers (0, 1) don't work



    

      

        Owner over 18?

        

        <%= radio_button( :guarantor, :over_eighteen.to_s, true )%> Yes   

        <%= radio_button( :guarantor, :over_eighteen, false )%> No

create object fom underscore_syntax

ovhaag (Oliver Haag) — Mon, 27 Nov 2006 05:15:18 GMT

// camelize - from underscore_syntax to Uppercas/ClassSyntax
// constantize - create instance
// (params[:property]) -- read data from web-form



    @property = property_type.camelize.constantize.new(params[:property])

transform normal projet to rails project in radrails

ovhaag (Oliver Haag) — Sun, 12 Nov 2006 09:36:59 GMT

// in radrails when you import a project from subversion
// it is a normal project

// in the menu I found no way to transform it
// but so it worked for me:

// 1. edit the .project file and copy the natueres block



	

		org.radrails.rails.ui.railsnature

		org.rubypeople.rdt.core.rubynature

// 2. copy the buildSpec block too
// (I'm not sure if this is necessary, I did both and it worked)



	

		

			org.rubypeople.rdt.core.rubybuilder

// 3. restart radrails and
// 4. add a webrick-server to the project
// and you are done

find out the current url / uri in *.rhtml file

ovhaag (Oliver Haag) — Mon, 16 Oct 2006 19:40:40 GMT

// find out the current url / uri in *.rhtml file
// is quite simple with the request object



<% page = request.request_uri %>

page: <%= page %>

// but then different urls mean the same page
// (../admin = ../admin/ = ../admin/index = ..admin/index/)
// and maybe the id is unwanted too (../admin/show/8)
// so below is an alternative with control on which parameter is used



<% page = "/" + request.path_parameters['controller'] + "/" + request.path_parameters['action'] %>

page: <%= page %>

rails generator syntax

ovhaag (Oliver Haag) — Sun, 08 Oct 2006 18:52:22 GMT

// generate application



rails projectname

// generate migration.



ruby script/generate migration migration_name

ruby script/generate migration add_price

// generate model
// we can give a list of columns and types
// :string, :text, :integer, :decimal, :float, :date, ...



ruby script/generate model model_name

ruby script/generate model user name:string hashed_password:string salt:string

// generate controller



ruby script/generate controller controller_name method_name(s)

ruby script/generate controller store index

// generate scaffold



ruby script/generate scaffold model_name controller_name

ruby script/generate scaffold product admin

redefine [] operator in ruby

ovhaag (Oliver Haag) — Sun, 08 Oct 2006 15:48:34 GMT

// the parameter is written behind the operator in parantheses
// the parameter must be an integer/fixnum
//
// i.e.
// def [](chunk)
// @internal_id_hash[chunk.chunk_id]
// end
// is not possible





class ChunkList

  ..



  def [](chunk_id)

    @internal_id_hash[chunk_id]

  end

end

singleton in ruby

ovhaag (Oliver Haag) — Sat, 07 Oct 2006 14:47:26 GMT

// simple singleton



class Singleton 

  private_class_method :new

  @@singleton = nil

  

  def Singleton.create

    @@singleton = new unless @@singleton

    @@singleton

  end

end

count characters

ovhaag (Oliver Haag) — Wed, 04 Oct 2006 21:15:58 GMT

// Sample Output, "character (byte) occurs n times", 32 = space
// s (115) occurs 3 times
// n (110) occurs 1 times
// ..
// (32) occurs 3 times



class Counter

  

def initialize()

  @characters = Hash.new(0)

end



def read()

  @text = IO.read("text.txt")

end



def count_chars

  @text.each_byte do |ch|

  @characters[ch] +=1

  end

end



def report  

  @characters.each do |key, value|

    puts "#{key.chr} (#{key}) occurs #{value} times"

  end  

end



end

// usage



count = Counter.new()

count.read

count.count_chars

count.report

show image in selection-box

ovhaag (Oliver Haag) — Mon, 02 Oct 2006 20:45:14 GMT

// works only in mozilla







..



Select Company