Make blank params[] nil

Question

When a user submits a form and leaves certain fields blank, they get saved as blank in the DB. I would like to iterate through the params[:user] collection (for example) and if a field is blank, set it to nil before updating attributes. I can't figure out how to do this though as the only way I know to iterate creates new objects:

coll = params[:user].each do |c|     if c == ""        c = nil     end end 

Thanks.

Answer 1

Consider what you're doing here by using filters in the controller to affect how a model behaves when saved or updated. I think a much cleaner method would be a before_save call back in the model or an observer. This way, you're getting the same behavior no matter where the change originates from, whether its via a controller, the console or even when running batch processes.

Example:

class Customer < ActiveRecord::Base   NULL_ATTRS = %w( middle_name )   before_save :nil_if_blank    protected    def nil_if_blank     NULL_ATTRS.each { |attr| self[attr] = nil if self[attr].blank? }   end end 

This yields the expected behavior:

>> c = Customer.new => #<Customer id: nil, first_name: nil, middle_name: nil, last_name: nil> >> c.first_name = "Matt" => "Matt" >> c.middle_name = "" # blank string here => "" >> c.last_name = "Haley" => "Haley" >> c.save => true >> c.middle_name.nil? => true >> 

Answer 2

If you just want to kill the blanks, you can just do params.delete_if {|k,v| v.blank?}.