Rails - Jun 2006 - Generator that alters existing files

What''s the best way to go about writing a generator that can add text
into an
existing file?

The point in the file is marked with a unique token, I want to insert a few
lines after the line with the token on it.

Is this possible/easy/already done by someone?

Thanks

On Jun 2, 2006, at 6:01 AM, Gareth Adams wrote:
> What''s the best way to go about writing a generator that can add  
> text into an
> existing file?
>
> The point in the file is marked with a unique token, I want to  
> insert a few
> lines after the line with the token on it.
>
> Is this possible/easy/already done by someone?
>
> Thanks
>
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails

	It is a bit dangerous to add code to a file like that already has  
content. But it can be done. I don''t think there is any direct  
support for it in the generator stuff. But you could do something  
like this:


# in app/models/foo.rb

class Foo

   def initialize
   end

   #REPLACEME

end


# in generator or script

def add_to_file(filename, placeholder, replacement_code)
   finished_product = IO.read(filename).gsub! /#{Regexp.quote 
(placeholder)}/, replacement_code
   File.open(filename, ''w+'') { |f| f.write finished_product }
end

code =<<-EOF
   def additional_method
     # whatever here
   end
EOF

placeholder = "#REPLACEME"

file = "#{RAILS_ROOT}/app/models/foo.rb"

add_to_file(file, placeholder, code)

# foo.rb after the code is added to it

class Foo

   def initialize
   end

   def additional_method
     # whatever here
   end

end


Cheers-
-Ezra