Eventmachine talk - Oct 2006 - call EventMachine.connect from initialize

Trying to call, EventMachine::conect from initialize method of a class
never works.

Here, I am getting exception:
acts_as_client.rb:44:in `initialize'': wrong number of arguments (0 for
1) (ArgumentError)
        from acts_as_client.rb:44:in `initialize''
        from acts_as_client.rb:77:in `initialize''
        from
/usr/lib/ruby/gems/1.8/gems/eventmachine-0.7.0/lib/eventmachine.rb:718:in
`event_callback''
        from
/usr/lib/ruby/gems/1.8/gems/eventmachine-0.7.0/lib/eventmachine.rb:201:in
`run''
        from acts_as_client.rb:76:in `initialize''
        from acts_as_client.rb:82


However, If i move EventMachine.connect to another class method , it
works, but that way...meta programming hooks throw up errors, like:

set_instance_variables undefined...

Any solution?


require ''rubygems''
require ''eventmachine''

class MyProtocolHandler < EventMachine::Connection

  def parse_foobar data
    data.chomp!
    @game << data
    send_data (@game+"\n")
  end

  def post_init
    p "New connection made"
  end

  def self.metaclass; class << self; self; end; end;

  def self.traits( *args )
    return @traits if args.empty?

    attr_accessor *args
    args.each do |a|
      metaclass.instance_eval do
        define_method( a ) do |val|
          @traits ||= {}
          @traits[a] = val
        end
      end
    end

    # just inheriting this stupid thing will enable call to initialize method
    class_eval do
      define_method( :initialize ) do|*arry|
        super *arry
        self.class.traits.each do |k,v|
          instance_variable_set("@#{k}",v)
        end
        EventMachine.connect("localhost",3901,self)
      end

    end

    # method that defines the receive_data
    class_eval do
      define_method( :receive_data ) do |data|
        self.send("parse_#{@format}",data)
      end
    end

  end # end of self.traits method

  traits :life,:game,:format
end # class MyProtocolHandler

class FooHandler < MyProtocolHandler
  life 100
  game ""
  format ''foobar''
end

class Base
  # will have data_client sockets
  # some other foobar

  def initialize
    EventMachine.run {
      bar = FooHandler.new
    }
  end
end

base = Base.new


--
There was only one Road; that it was like a great river: its springs
were at every doorstep, and every path was its tributary.

On 10/28/06, hemant <gethemant at gmail.com>
wrote:
>
> Trying to call, EventMachine::conect from initialize method of a class
> never works.
>
>
>     # just inheriting this stupid thing will enable call to initialize
> method
>     class_eval do
>       define_method( :initialize ) do|*arry|
>         super *arry
>         self.class.traits.each do |k,v|
>           instance_variable_set("@#{k}",v)
>         end
>         EventMachine.connect("localhost",3901,self)
>       end
>
>     end



I''m having trouble following all this metaprogramming. I assume you
defined
MyProtocolHandler#initialize inside a class_eval so that self would refer to
the class, in the EventMachine#connect call. I''ll bet this is causing
some
kind of problem. Remember, #connect creates a new instance of the class that
is given as its third argument. So I don''t see how this could work
without
causing an infinite regress.
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On 10/28/06, Francis Cianfrocca <garbagecat10 at gmail.com>
wrote:
> On 10/28/06, hemant <gethemant at gmail.com> wrote:
> > Trying to call, EventMachine::conect from initialize method of a class
> > never works.
> >
> >
> >     # just inheriting this stupid thing will enable call to initialize
> method
> >     class_eval do
> >       define_method( :initialize ) do|*arry|
> >         super *arry
> >         self.class.traits.each do |k,v|
> >           instance_variable_set("@#{k}",v)
> >         end
> >         EventMachine.connect("localhost",3901,self)
> >       end
> >
> >     end
>
>
>
> I''m having trouble following all this metaprogramming. I assume
you defined
> MyProtocolHandler#initialize inside a class_eval so that self would refer
to
> the class, in the EventMachine#connect call. I''ll bet this is
causing some
> kind of problem. Remember, #connect creates a new instance of the class
that
> is given as its third argument. So I don''t see how this could work
without
> causing an infinite regress.
Ok..calling connect from initialize would never work out...so i did a
small workaround and move that to a class method and whoever wants an
instance of the class of the would call that method. Working pretty
fine now.

Basically, I wanted to write a higher level class, that can act as a
server and client both and hooks up proper parsers based on attributes
dynamically.



--
There was only one Road; that it was like a great river: its springs
were at every doorstep, and every path was its tributary.