How to limit some of markdown features for first post?

Development
4

@Jagster @pfaffman

Please imagine that the plugin adds some custom BBCode tags, or wraps any text with a custom HTML tag for later use, such as decorating it. I don’t want it to take effect outside the first post (or based on other conditions), since I don’t need it and it may cause some side effects.

Also, I may have found a possible solution on the server side. It wraps the cook method of the Post model. I haven’t tested it yet.

class ::Post
  # wrap the original cook method to add features option
  # see the markdown method in lib/pretty_text.rb
  alias_method :original_cook, :cook
  def cook(raw, opts = {})
    features = {
      'feature-name':  is_first_post?
    }

    if opts.has_key?(:features)
      opts[:features].merge!(features)
    else
      opts[:features] = features
    end

    original_cook(raw, opts)
  end
end