Ruby on Rails Edit File Template? - ruby-on-rails

Question

I have a HTML/CSS File laid out with a bunch of areas that need adding. I have a ruby on rails application that would have a bunch of form elements that would then need to be added to this HTML/CSS file (it doesn't need to be shown or anything, just edited and then saved). I don't really understand how I can do this. I was looking at the file class, but got lost very quickly.
Any easy way to do this?

Answer 1

Writing to a file in Ruby is very simple:
File.open(filename, 'w') do |f|
f.write(content)
end
For an example in Rails try the following steps. Generate a new Rails app and a dummy scaffold by running:
rails new erbfun
cd erbfun
rails g scaffold Stylesheet custom_css:text
rake db:migrate
mkdir -p public/system/stylesheets
Then do something like this in your model:
class Stylesheet < ActiveRecord::Base
require 'erb'
FOLDER = File.join(Rails.public_path,'system/stylesheets')
TEMPLATE = <<-CSS
body {
font-family: Helvetica;
}
<%= custom_css %>
/* some css comment here ... */
CSS
def save_to_file
template = ERB.new(TEMPLATE)
document = template.result(binding)
filename = File.join(FOLDER,"stylesheet-#{Time.now.to_i}.css")
File.open(filename, 'w') do |f|
f.write(document)
end
end
end
and then try it out:
$ rails c
Loading development environment (Rails 3.2.2)
1.9.3p125 :001 > s = Stylesheet.new custom_css: 'foobar'
=> #<Stylesheet id: nil, custom_css: "foobar", created_at: nil, updated_at: nil>
1.9.3p125 :002 > s.save!
...
=> true
1.9.3p125 :003 > s.save_to_file
=> 94
1.9.3p125 :004 > exit
$ cat public/system/stylesheets/stylesheet-1332633386.css
body {
font-family: Helvetica;
}
foobar
/* some css comment here ... */