What is the best practices place to manipulate form data before saving in Rails 3?

Question

From the pointview of rails best practices, what is the best place to manipulate form data before saving?

For instace, on a contact form, I want to make sure that all data is saved in capitalized form ( don't you hate when PEOPLE SHOUT AT YOU in their "please contact me" form submission? :-) )

• is it better to do manipulation in controller? I could either do it in create, or move it into some sort of private method , that will capitalize all string attributes of the object before saving / updating?

Or

• is it better do in the model before_save? It makes sense to me that it should be done in the model since I probably want that to be the same for all records, no matter whether I manipulate on them in a rake task or through the web interface.

Bonus:

Also where would I place it if I want that that on ALL my models, with the ability to override default on a case by case basis? Application controller? There might be some special cases where you want to save value without capitalizing - i.e. brand name products that don't capitalize (i.e. utorrent) or a last name that should have multiple caps in the name (i.e. Irish & Scottish names like McDonald)

Thank you!

Answer 1

Ok based on the suggestions from other replies I came up with this solution:

lib/clean_strings.rb

module ActiveRecord
  class Base
    attr_accessor :dont_capitlize, :dont_strip

    before_save :_capitalize_strings, :unless => :dont_capitlize
    before_save :_strip_whitespaces,  :unless => :dont_strip

    def _capitalize_strings
      self.attributes.each_pair do |key, value|
        self[key] = value.capitalize if value.respond_to?('capitalize')
      end
    end


    def _strip_whitespaces
      self.attributes.each_pair do |key, value|
        self[key] = value.strip if value.respond_to?('strip')
      end
    end

  end
end

in environment.rb addded

require "clean_strings"

Now whenever I do

@a.dont_capitalize = true
@a.save!

it cleans it before saving according to my rules ( it will strip whitespace, but not capitalize it ). Obviously it needs more fine tuning, but i think it's a good way to define format rules for commonplace things. This way I don't need to sanitize every and each form input for things like extra whitespaces, or people who don't know where the CAPS LOCK is !!!

Thank you all for your input ( all upvoted).

Answer 2

the easiest place to put this is in your model. I would suggest using either before_save or even before_validation if you feel that fits better. Something like this would do the trick:

before_save :upcase_content

def upcase_content
  self.content = self.content.upcase
end

Additionally if you wanted to allow for exceptions of a case by case basis you could add an attr_accessor to your model.

class MyModel < ActiveRecord::Base
attr_accessor :dont_upcase

before_save :upcase_content, :unless => :dont_upcase
...
end

then when you create a model set the accessor to true

@model = Model.new(:brand_name => utorrent)
@model.dont_upcase = true
@model.save!

Answer 3

The best place to put this is in your model, that way you have a fat model and a skinny controller, which is a "good thing".

If you want to have this be available for all of your models my suggestion is to use a module which contains your shared functionality and then include that in all the models you want to have the default behavior.