Rails - Mar 2007 - Strange 'string modified' error!

Hi,

Got this strange error message coming from the second instance of the
''scan'' method (line 39) on the text string. Any clues. Really
stumped
me... It was working fine, then suddenly - boom it stopped.

    ...

    text.scan(/\/\.asset\.[0-9]*\.url\./) do |url|
      id = url.gsub(/[^0-9]/,'''').to_i
      if asset = Asset.find(id)
        text.gsub!(url, ''/'' + asset.url_for_link)
      end
    end

39  text.scan(/\.asset\.[0-9]*\.title\./) do |url|
      id = url.gsub(/[^0-9]/,'''').to_i
      if asset = Asset.find(id)
        text.gsub!(url, CGI.escapeHTML(asset.title))
      end
    end

    ...

The error is (in summary):

--

RuntimeError in SiteController#show_page

  string modified

RAILS_ROOT: /var/www/downing/current/config/..

Application Trace
...
#{RAILS_ROOT}/app/filters/xhtml/xhtml_filter.rb:39:in `scan''
...

--


Many thanks in advance.

Best,

~ Mark Dodwell

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

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---

In the end I fixed it. I initially replaced the ''scan'' with
''gsub!'' as
the ''text'' string was being changed inside the block passed to
''scan''
which was causing the ''string modified'' error.

However, even with ''gsub!'' I was receving the same error. This
seems to
be becuase the multiple ''gsub!'' invocations are not thread
safe? In the
end I had to use a mutex:

  require ''thread''
  mutex = Mutex.new

  ...

  mutex.synchronize  do
    text.gsub!(/\/\.asset\.([0-9]*)\.url\./) { ''/'' + 
Asset.find($1).url_for_link }
  end

  mutex.synchronize  do
    text.gsub!(/\.asset\.([0-9]*)\.title\./) { 
CGI.escapeHTML(Asset.find($1).title) }
  end

  ...

Not sure if this is actually the best solution, but it does work now!

~ Mark Dodwell

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

--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---