Before Validation loop through self attributes for modification - ruby-on-rails

Question

I have created a simple before_validation:
before_validation :strip_tabs
def strip_tabs
end
In my class I want to loop through all my attributes and remove tabs from each value. Most posts I found on SO are people who want to set 1 attribute. But I want to edit all my values.
Question:
How can I loop all self attributes of a model and edit them.
Friend suggested this, but content_column_names does not exist:
self.content_column_names.each {|n| self[n] = self[n].squish}
UPDATE 1: More code:
class PersonalInfo
include ActiveModel::Validations
include ActiveModel::Validations::Callbacks
extend ActiveModel::Translation
extend ActiveModel::Callbacks
include Sappable
require 'ext/string'
attr_accessor \
:first_name, :middle_name, :last_name,:birthdate,:sex,
:telephone,:street,:house_number,:city,:postal_code,:country,
:e_mail, :nationality, :salutation, :com_lang
validates :e_mail, :email => {:strict_mode => true}
validate :validate_telephone_number
validate :age_is_min_17?
before_validation :strip_tabs
def strip_tabs
binding.remote_pry
end
def age_is_min_17?
birthdate_visible = PersonalField.not_hidden.find_by_name "BIRTHDATE"
if birthdate_visible && birthdate && birthdate > (Date.current - 17.years)
#errors.add(:birthdate, I18n.t("apply.errors.birthdate"))
end
end
def validate_telephone_number
telephone_visible = PersonalField.not_hidden.find_by_name "TELEPHONE"
telephone_current = telephone.dup
if telephone_visible && telephone_current && !telephone_current.empty?
if telephone_current[0] == '+' || telephone_current[0] == '0'
telephone_current[0] = ''
#errors.add(:telephone, I18n.t("apply.errors.telephone")) if !telephone_current.is_number?
else
#errors.add(:telephone, I18n.t("apply.errors.telephone"))
end
end
end
def initialize(hash)
simple_attributes = [:first_name, :middle_name, :last_name,:birthdate,:sex,
:telephone,:street,:house_number,:city,:postal_code,:country,
:e_mail, :nationality, :salutation, :com_lang]
simple_attributes.each do |attr|
set_attr_from_json(attr, hash)
end
set_attr_from_json(:birthdate, hash) {|date| Date.parse(date) rescue nil}
end
end
Update 2: Rails Version:
I'm using Rails '3.2.17'

Answer 1

You can do as following:
before_validation :strip_tabs
def strip_tabs
self.attributes.map do |column, value|
self[column] = value.squish.presence
end
end
But I think that .squish will not work on created_at, updated_at, id, ... Because they are not String!
def strip_tabs
self.attributes.map do |column, value|
self[column] = value.kind_of?(String) ? value.squish.presence : value
end
end
Since your class is not a Rails model (ActiveRecord::Base), you can do as following:
def strip_tabs
self.instance_variables.map do |attr|
value = self.instance_variable_get(attr)
value = value.squish if value.kind_of?(String)
self.instance_variable_set(attr, value)
end
end

Answer 2

This should work
def strip_tabs
self.attributes.each do |attr_name, attr_value|
modified_value = ... # calculate your modified value here
self.write_attribute attr_name, modified_value
end
end

Answer 3

Because it's not an ActiveRecord model you won't have attributes or column_names, but you already have an array of your attribute names in your initialize function. I would suggest making that into a constant so you can access it throughout the model:
class PersonalInfo
include ActiveModel::Validations
include ActiveModel::Validations::Callbacks
extend ActiveModel::Translation
extend ActiveModel::Callbacks
include Sappable
require 'ext/string'
SIMPLE_ATTRIBUTES = [:first_name, :middle_name, :last_name,:birthdate,:sex,
:telephone,:street,:house_number,:city,:postal_code,:country,
:e_mail, :nationality, :salutation, :com_lang]
attr_accessor *SIMPLE_ATTRIBUTES
before_validation :strip_tabs
def strip_tabs
SIMPLE_ATTRIBUTES.each{ |attr| self[attr] = self[attr].squish }
end
...
def initialize(hash)
SIMPLE_ATTRIBUTES.each do |attr|
set_attr_from_json(attr, hash)
end
set_attr_from_json(:birthdate, hash) {|date| Date.parse(date) rescue nil}
end
end