Rails - How to use a Helper Inside a Controller

Question

While I realize you are supposed to use a helper inside a view, I need a helper in my controller as I'm building a JSON object to return.

It goes a little like this:

def xxxxx

   @comments = Array.new

   @c_comments.each do |comment|
   @comments << {
     :id => comment.id,
     :content => html_format(comment.content)
   }
   end

   render :json => @comments
end

How can I access my html_format helper?

Answer 1

Note: This was written and accepted back in the Rails 2 days; nowadays grosser's answer is the way to go.

Option 1: Probably the simplest way is to include your helper module in your controller:

class MyController < ApplicationController
  include MyHelper
    
  def xxxx
    @comments = []
    Comment.find_each do |comment|
      @comments << {:id => comment.id, :html => html_format(comment.content)}
    end
  end
end

Option 2: Or you can declare the helper method as a class function, and use it like so:

MyHelper.html_format(comment.content)

If you want to be able to use it as both an instance function and a class function, you can declare both versions in your helper:

module MyHelper
  def self.html_format(str)
    process(str)
  end
    
  def html_format(str)
    MyHelper.html_format(str)
  end
end