From: Stefano Crocco <stefano.crocco@...>
Date: 2011-08-05T01:19:11+09:00
Subject: Re: Corrections in a Class

On Friday 05 August 2011 01:05:44 Rubyist Rohit wrote:
> Below is the code of my initial Class in the Ruby world. I want to make
> this Class a static class so that I can directly call methods,
> connectViaFTP and disconnectFTP.
> 
> I also want to improve the way it is written.
> 
> ==================================================
> require 'net/ftp'
> 
> class EstablishRemoteConnection
> 
>   #Constants
>     ServerName = "my FTP Server URL"
>     UserName = "My Username"
>     Password = "My Password"
>     FilePath = "My remote Sub Folder"
> 
>   #FTP instance
>     ftp=Net::FTP.new
> 
>   public def connectViaFTP
> 
>            ftp.connect(ServerName,21)
>            ftp.login(UserName,Password)
>            ftp.chdir(FilePath)
>            #ftp.getbinaryfile(filename)
>          end
> 
>   public def disconnectFTP
>           ftp.close
>          end
> end
> =================================================

1. remove the calls to public. By default methods are public, so they're not 
needed.
2. if you want to be able to write EstablishRemoteConnection.connectViaFTP and 
EstablishRemoteConnection.disconnectViaFTP, you need to make those methods 
class methods. To do this, instead of writing
  def connectViaFTP
write

  def self.connectViaFTP

3. Your code won't work because the FTP instance is a local variable, which 
will have long disappeared when connectViaFTP or disconnectFTP will be called. 
You need either to make it a constant, calling it Ftp rather than ftp, or make 
it a class instance variable (that is, an instance variable of class 
EstablishRemoteConnection):

  @ftp = Net::FTP.new

I hope this helps

Stefano