Rails sha1 hash generator

Question

Hi hopefully somebody can help me out. I'm a bit stuck at the moment. I'm trying to create an app for a tracking system, I currently have a table called sdel_hashed. Following online videos I so far set up digest/sha1 to work partly. If I enter the following commands in the console:

sdel = Sdel.find(1)
sdel.hashed_sdel = Sdel.hash('secret')
sdel.save

And then view the record in the browser it show up as the hash and not secret, but if I try and enter the word secret through the new action it doesn't get hashed. I think there is maybe something missing in the create action but I cannot find answers anywhere. i would greatly appreciate any help. I'll include now what I have in my controller and model. Thanks

model sdel

require 'digest/sha1'
class Sdel < ActiveRecord::Base
  attr_accessible :hashed_sdel

  def self.hash(sdel="")
     Digest::SHA1.hexdigest(sdel)
  end

end

controller sdels

class SdelsController < ApplicationController
  def list
    @sdel = Sdel.all
  end

  def new
    @sdel = Sdel.new
  end

  def create
    @sdel = Sdel.new(params[:sdel])
    if @sdel.save
      redirect_to(:action => 'list')
    else
      render('new')
    end
  end
end

Migration file

class CreateSdels < ActiveRecord::Migration
  def change
    create_table :sdels do |t|
      t.string "hashed_sdel"
      t.timestamps
    end
  end
end

Answer 1

Sounds like you may want to use a before_save filter to invoke the hash class method on the Sdel model prior to saving when the attribute has been modified. Perhaps something along the lines of this:

require 'digest/sha1'

class Sdel < ActiveRecord::Base
  attr_accessible :hashed_sdel

  before_save { self.hashed_sdel = self.class.hash(hashed_sdel) if hashed_sdel_changed? }

  def self.hash(sdel="")
    Digest::SHA1.hexdigest(sdel)
  end
end

This way, if you have a form that has a text_field for your hashed_sdel attribute, it will automatically get run through the hash class method you have before it the record gets saved (assuming the attribute has changed from it's previous value).