Newbie problem of Class attributes

ruby-talk
1

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.

···

--
Posted via http://www.ruby-forum.com/.

2

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

···

On 10/10/06, Dipesh Batheja <dipesh_batheja@yahoo.com> wrote:

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.

--
Posted via http://www.ruby-forum.com/\.

3

<code>
#! /usr/bin/env ruby -w

class A
    class << self
       attr_accessor :foo
    end
end

A.foo = 'bar'
A.foo # => "bar"
</code>

Regards, Morton

···

On Oct 10, 2006, at 5:18 PM, Dipesh Batheja wrote:

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.

4

What means 'class << self' ? I don't understand...

Plz anyone let me know secret ; )

Thanks.

···

On Oct 11, 6:56 am, Morton Goldberg <m_goldb...@ameritech.net> wrote:

On Oct 10, 2006, at 5:18 PM, Dipesh Batheja wrote:

> 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.<code>
#! /usr/bin/env ruby -w

class A
    class << self
       attr_accessor :foo
    end
end

A.foo = 'bar'
A.foo # => "bar"
</code>

Regards, Morton

5

Hi --

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.

--
Posted via 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

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

···

On Wed, 11 Oct 2006, Tim Pease wrote:

On 10/10/06, Dipesh Batheja <dipesh_batheja@yahoo.com> wrote:

--
                   David A. Black | dblack@wobblini.net
Author of "Ruby for Rails" [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog) [2] | Co-director, Ruby Central, Inc. [4]
[1] Ruby for Rails | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com | [4] http://www.rubycentral.org

6

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

It is much better than my on line explanation.

Blessings,
TwP

···

On 10/10/06, Mait <mattengi@gmail.com> wrote:

What means 'class << self' ? I don't understand...

Plz anyone let me know secret ; )

Thanks.

7

Thanks Tim,

···

On Oct 11, 7:28 am, "Tim Pease" <tim.pe...@gmail.com> wrote:

On 10/10/06, Mait <matte...@gmail.com> 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

It is much better than my on line explanation.

Blessings,
TwP

8

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 --type client --force
ignored element: {http://www.w3.org/2001/XMLSchema}list
ignored attr: {}default
ignored attr: {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.)

Second, I tried this code:

require 'soap/wsdlDriver'
wsdl_url = '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 =
"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?