From: badboy <badboy@...>
Date: 2009-01-14T22:36:52+09:00
Subject: Re: Trying to parse an array of rss feeds without success

Louis-pierre Lp.dahito schrieb:
> hey folks,
> 
> I'm trying to make a basic feeds parser... It works fine when I have one
> feed only but as soon as I try to parse an array of feeds, it's gonna
> parse it correctly but I won't be able to fetch any data out of it...
> Here is my code...
> 
> class Site
>   attr_accessor :domain, :name
> 
>   def initialize
>     @domain = domain
>     @name = name
>   end
> end
> 
> 
> a = Site.new
> a.domain = "http://www.mininova.org/rss.xml"
> a.name = "mininova"
> 
> b = Site.new
> b.domain = "http://static.demonoid.com/rss/0.xml"
> b.name = "demonoid"
> 
> c = Site.new
> c.domain = "http://rss.thepiratebay.org/0"
> c.name = "thepiratebay"
> 
> allfeeds = [ a, b, c ]
> 
> require 'rss/1.0'
> require 'rss/2.0'
> require 'open-uri'
> 
> def parse_torrents(source)
>   # source = self.domain # url or local file
>    content = "" # raw content of rss feed will be loaded here
>    open(source) do |s| content = s.read end
>    RSS::Parser.parse(content, false)
> end
> 
> torrents = allfeeds.each { |feed| parse_torrents(feed.domain) }
> 
> torrents.each { |t| puts t.channel.title }
> 
> The error message I get is only on the last line of code... removing the
> last line doesn't show any error message.
> 
> Here is the message i get from RubyMate:
> 
> NoMethodError: undefined method ‘channel’ for #<Site:0x8a520>
> 
> at top level  in global.rb at line 38
> method each  in global.rb at line 38
> at top level  in global.rb at line 38
> Program exited.
> 
> I need help even though it's a pretty basic question...
> 
> Thank you guys...
the error message has all you need to get rid of this mistake.
   "...for #<Site...>"

Now start irb and type something like:
   irb> myarray = [1,2,3]
   irb> newarray = myarray.each { |i| i * 10 }
   irb> p newarray
do you see it?
now try Array#map:
   irb> myarray = [1,2,3]
   irb> newarray = myarray.map { |i| i * 10 }
   irb> p newarray

see the difference?