Rails and Redis: how should I handle validation here?

Question

I'm new to rails. I am using Redis instead of something backed w/ ActiveRecord. I need to validate the presence of location, categories, start_date, and end_date. I then need to check that start_date and end_date are valid dates, that start_date comes before end_date. And that location matches a regex [A-Za-z_]. And that categories.length> 0. Since the start_date and end_date parameters in my model's setters are Date objects, should I check for valid dates and convert them in my controller. Then have my model's setters take care of the rest of the validation?

I just don't know where to put the validations: in my model or controller?

Model:

class MyThingie
 def self.set_x(location, categories, start_date, end_date, value)
 updates = {}
 for date in (start_date .. end_date)
 # ...
 end
 $redis.mset(*updates.flatten)
 end
 def self.set_y(location, categories, default)
 updates = {}
 for category in categories
 # ...
 end
 $redis.mset(*updates.flatten)
 end
 def self.set_z(location, categories, start_date, end_date, block)
 if block
 updates = {}
 for date in (start_date .. end_date)
 # ...
 end
 $redis.mset(*updates.flatten)
 else
 deletes = []
 for date in (start_date .. end_date)
 # ...
 end
 $redis.del(*deletes)
 end
 end
end

Controller:

class MyThingieController < ApplicationController
 # ...
 def create
 begin
 method = params[:method]
 location = params[:location]
 categories = params[:categories]
 s_start_date = params[:start_date]
 s_end_date = params[:end_date]
 if method == "normal"
 value = params[:value]
 start_date = Date.strptime(s_start_date, "%m/%d/%Y")
 end_date = Date.strptime(s_end_date, "%m/%d/%Y")
 MyThingie.set_x(location, categories, start_date, end_date, value)
 elsif method == "default"
 default = params[:default]
 MyThingie.set_y(location, categories, default)
 elsif method == "block"
 block = params[:block]
 start_date = Date.strptime(s_start_date, "%m/%d/%Y")
 end_date = Date.strptime(s_end_date, "%m/%d/%Y")
 MyThingie.set_z(location, categories, start_date, end_date, block)
 else
 raise "Invalid form submit"
 end
 rescue Exception => e
 errors = [e.message]
 respond_to do |format|
 format.json do
 json = Jsonify::Builder.new
 json.errors errors
 a = json.compile!
 render :status => 400, :json => a
 end
 end
 else
 respond_to do |format|
 format.json do
 json = Jsonify::Builder.new
 json.msg "Update successful."
 a = json.compile!
 render :json => a
 end
 end
 end
 end

Here the keys are like

mythingie:location:date = value

mythingie:location:default = default

mythingie:location:date:z = "true"

Answer 1

In your model.

You can include ActiveModel::Validations directly in your model without relying on ActiveRecord for persistence.

See ActiveModel::Validations & the date_validator gem

A quick example more relevant to you;

class MyThingie
 include ActiveModel::Validations
 validates :start_date, :presence => true 
 validates :end_date, :presence => true 
 # Check out the date_validator gem, it allows things like 
 validates_date_of :end_date, :after => :start_date
 validates_format_of :location, :with => /[A-Za-z]/
 # ... 
end

Answer 2

You should not validate your model in controller. Imagine situation, where you need to create another controller, for example it will be the API controller with same logic. What you will do? Copy your code and paste? And what about unit testing? ;)

http://www.sitepoint.com/10-ruby-on-rails-best-practices/