# Newbie problem of Class attributes **URL:** \ **Category:** Ruby\ **Created:** [October 10, 2006, 11:18pm UTC](https://www.ruby-forum.com/t/newbie-problem-of-class-attributes/71710 "2006-10-10T23:18:26Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![dipeshbatheja](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b19c9b/32.png) [@dipeshbatheja](https://www.ruby-forum.com/u/dipeshbatheja)\ **Post date:** [October 10, 2006, 11:18pm UTC](https://www.ruby-forum.com/t/newbie-problem-of-class-attributes/71710/1 "2006-10-10T23:18:26Z")
I am trying to create a class level attribute which can read and write. I am doing something like this: def self.selected\_client – my code – end def self.selected\_client=(value) – my code – end but its seems that the Ruby interpreter is not liking this. Can someone tell me how to create class level attributes that can read and write. ---
**Author:** ![dipeshbatheja](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b19c9b/32.png) [@dipeshbatheja](https://www.ruby-forum.com/u/dipeshbatheja)\ **Post date:** [October 10, 2006, 11:25pm UTC](https://www.ruby-forum.com/t/newbie-problem-of-class-attributes/71710/2 "2006-10-10T23:25:13Z")
On 10/10/06, Dipesh B. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > but its seems that the Ruby interpreter is not liking this. Can someone > tell me how to create class level attributes that can read and write. > > – > Posted via [http://www.ruby-forum.com/](http://www.ruby-forum.com/). class A def self.var() @@var end defl self.var=(v) @@var = v end end A.var = 1 A.var If you try to access a class variable before it is set, the interpreter will throw a NameError at you. Blessings, TwP ---
**Author:** ![dipeshbatheja](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b19c9b/32.png) [@dipeshbatheja](https://www.ruby-forum.com/u/dipeshbatheja)\ **Post date:** [October 10, 2006, 11:57pm UTC](https://www.ruby-forum.com/t/newbie-problem-of-class-attributes/71710/3 "2006-10-10T23:57:14Z")
On Oct 10, 2006, at 5:18 PM, Dipesh B. wrote: > end > > but its seems that the Ruby interpreter is not liking this. Can > someone > tell me how to create class level attributes that can read and write. ` #! /usr/bin/env ruby -w class A class << self attr_accessor :foo end end A.foo = ‘bar’ A.foo # => “bar” ` Regards, Morton ---
**Author:** ![dipeshbatheja](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b19c9b/32.png) [@dipeshbatheja](https://www.ruby-forum.com/u/dipeshbatheja)\ **Post date:** [October 11, 2006, 12:21am UTC](https://www.ruby-forum.com/t/newbie-problem-of-class-attributes/71710/4 "2006-10-11T00:21:16Z")
On Oct 11, 6:56 am, Morton G. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > def self.selected\_client=(value) > > attr\_accessor :foo > > end > > end > > A.foo = ‘bar’ > A.foo # =\> “bar” > > Regards, Morton What means ‘class \<\< self’ ? I don’t understand… Plz anyone let me know secret ; ) Thanks. ---
**Author:** ![dipeshbatheja](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b19c9b/32.png) [@dipeshbatheja](https://www.ruby-forum.com/u/dipeshbatheja)\ **Post date:** [October 11, 2006, 12:29am UTC](https://www.ruby-forum.com/t/newbie-problem-of-class-attributes/71710/5 "2006-10-11T00:29:17Z")
On 10/10/06, Mait [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > What means ‘class \<\< self’ ? I don’t understand… > > Plz anyone let me know secret ; ) > > Thanks. The ‘class \<\< self’ notation gives you access to the Singleton class for the object ‘self’. There is a great explanation on the RubyGarden wiki page … [http://wiki.rubygarden.org/Ruby/page/show/SingletonTutorial](http://wiki.rubygarden.org/Ruby/page/show/SingletonTutorial) It is much better than my on line explanation. Blessings, TwP ---
**Author:** ![dipeshbatheja](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b19c9b/32.png) [@dipeshbatheja](https://www.ruby-forum.com/u/dipeshbatheja)\ **Post date:** [October 11, 2006, 1:01am UTC](https://www.ruby-forum.com/t/newbie-problem-of-class-attributes/71710/6 "2006-10-11T01:01:19Z")
On Oct 11, 7:28 am, “Tim P.” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > There is a great explanation on the RubyGarden wiki page … > > [http://wiki.rubygarden.org/Ruby/page/show/SingletonTutorial](http://wiki.rubygarden.org/Ruby/page/show/SingletonTutorial) > > It is much better than my on line explanation. > > Blessings, > TwP Thanks Tim, ---
**Author:** ![dipeshbatheja](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b19c9b/32.png) [@dipeshbatheja](https://www.ruby-forum.com/u/dipeshbatheja)\ **Post date:** [October 11, 2006, 3:17am UTC](https://www.ruby-forum.com/t/newbie-problem-of-class-attributes/71710/7 "2006-10-11T03:17:28Z")
Hi – On Wed, 11 Oct 2006, Tim P. wrote: > > end > > def self.var() @@var end > > defl self.var=(v) @@var = v end > > end > > A.var = 1 > A.var I’d steer clear of class variables unless there’s some very compelling reason to use them. Classes can have regular attributes: class C def self.x @x end def self.x=(value) @x = value end end I realize Dipesh said “class level”, which could mean specifically using class variables, but then again, class variables aren’t really class level (they’re class/sub[sub[…]]class/instances-level). David ---
**Author:** ![dipeshbatheja](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b19c9b/32.png) [@dipeshbatheja](https://www.ruby-forum.com/u/dipeshbatheja)\ **Post date:** [October 11, 2006, 2:15am UTC](https://www.ruby-forum.com/t/newbie-problem-of-class-attributes/71710/8 "2006-10-11T02:15:24Z")
I’ve been trying to programmatically issue MSN Searches and processing the results. I’m having a hell of a time doing it and was wondering whether anyone had some coding or debugging advice. First, I tried wsdl2ruby to generate some classes to work with, but it pukes: C:\temp\>wsdl2ruby.rb --wsdl [http://soap.search.msn.com/webservices.asmx?wsdl](http://soap.search.msn.com/webservices.asmx?wsdl) --type client --force ignored element: {[http://www.w3.org/2001/XMLSchema](http://www.w3.org/2001/XMLSchema)}list ignored attr: {}default ignored attr: {[http://schemas.xmlsoap.org/ws/2004/08/addressing](http://schemas.xmlsoap.org/ws/2004/08/addressing)}Action I, [2006-10-10T16:36:52.259000 #2608] INFO – app: Creating class definition. W, [2006-10-10T16:36:52.259000 #2608] WARN – app: File ‘default.rb’ exists but overrides it. F, [2006-10-10T16:36:52.275000 #2608] FATAL – app: Detected an exception. Stopping … incomplete simpleType (ArgumentError) C:/program files/ruby/lib/ruby/1.8/wsdl/xmlSchema/simpleType.rb:33:in `base’ C:/program files/ruby/lib/ruby/1.8/wsdl/soap/classDefCreator.rb:217:in [snip] (BTW, wsdl2ruby works with [http://api.google.com/GoogleSearch.wsdl.](http://api.google.com/GoogleSearch.wsdl.)) Second, I tried this code: require ‘soap/wsdlDriver’ wsdl\_url = ‘[http://soap.search.msn.com/webservices.asmx?wsdl](http://soap.search.msn.com/webservices.asmx?wsdl)’ soap = SOAP::WSDLDriverFactory.new( wsdl\_url ).create\_rpc\_driver msn\_params = { ‘AppID’ =\> ‘1064081Cxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx’, ‘Query’ =\> ‘ruby programming language’, ‘CultureInfo’ =\> ‘en-US’, ‘SafeSearch’ =\> ‘Strict’, ‘Flags’ =\> ‘None’, ‘Requests’ =\> { ‘SourceRequest’ =\> { ‘Source’ =\> ‘Web’, ‘Offset’ =\> 0, ‘Count’ =\> 10, ‘ResultFields’ =\> ‘All’ } } } soap.search(:Request =\> msn\_params) And got this: irb(main):020:0\* soap.search(:Request =\> msn\_params) ArgumentError: incomplete simpleType from c:/Program F iles/ruby/lib/ruby/1.8/wsdl/xmlSchema/simpleType.rb:25:in `check_lexical_fo rmat' from c:/Program Files/ruby/lib/ruby/1.8/soap/mapping/wsdlliteralregistry.rb:113:in `simpleob j2soap’ [snip] Note: the Python equivalent of this code works just fine, so I think it has something to do with the way Ruby is processing SOAP. Third, I tried to do it without SOAP: require ‘rubygems’ require ‘open-uri’ require ‘rubyful\_soup’ url = “[ruby programming language - Search](http://search.live.com/results.aspx?q=ruby+programming+language&mkt=en-) us&FORM=LVSP&go.x=0&go.y=0&go=Search” page = open(url) page\_content = page.read soup = BeautifulSoup.new(page\_content) and I get this: irb(main):007:0\> soup = BeautifulSoup.new(page\_content) ArgumentError: invalid value for Integer: “0183” from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/htmltools-1.10/lib/html/sgml-parser.rb :335 :in `Integer' from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/htmltools-1.10/lib/html/sgml-parser.rb :335 :in `handle\_charref’ from c:/Program Files/ruby/lib/ruby/gems/1.8/gems/htmltools-1.10/lib/html/sgml-parser.rb :159 :in `goahead’ My next step is do to HTree/REXML, but I’d much rather use SOAP or BeautifulSoup to do this. Anyone got ideas?