StripAttributes
StripAttributes is an ActiveModel extension that automatically strips all
attributes of leading and trailing whitespace before validation. If the
attribute is blank, it strips the value to nil by default.
It works by adding a before_validation hook to the record. By default, all
attributes are stripped of whitespace, but :only and :except
options can be used to limit which attributes are stripped. Both options accept
a single attribute (only: :field) or arrays of attributes (except: [:field1, :field2, :field3]).
It's also possible to skip stripping the attributes altogether per model using the :if and :unless options.
Installation
Include the gem in your Gemfile:
gem "strip_attributes"
Examples
Default Behavior
class DrunkPokerPlayer < ActiveRecord::Base
strip_attributes
end
Using except
# all attributes will be stripped except :boxers
class SoberPokerPlayer < ActiveRecord::Base
strip_attributes except: :boxers
end
Using only
# only :shoe, :sock, and :glove attributes will be stripped
class ConservativePokerPlayer < ActiveRecord::Base
strip_attributes only: [:shoe, :sock, :glove]
end
Using if
# Only records with odd ids will be stripped
class OddPokerPlayer < ActiveRecord::Base
strip_attributes if: :strip_me?
def strip_me?
id.odd?
end
end
Using unless
# strip_attributes will be applied randomly
class RandomPokerPlayer < ActiveRecord::Base
strip_attributes unless: :strip_me?
def strip_me?
[true, false].sample
end
end
Using allow_empty
# Empty attributes will not be converted to nil
class BrokePokerPlayer < ActiveRecord::Base
strip_attributes allow_empty: true
end
Using collapse_spaces
# Sequential spaces in attributes will be collapsed to one space
class EloquentPokerPlayer < ActiveRecord::Base
strip_attributes collapse_spaces: true
end
Using replace_newlines
# Newlines in attributes will be replaced with a space
class EloquentPokerPlayer < ActiveRecord::Base
strip_attributes replace_newlines: true
end
Using regex
class User < ActiveRecord::Base
# Strip off characters defined by RegEx
strip_attributes only: [:first_name, :last_name], regex: /[^[:alpha:]\s]/
# Strip off non-integers
strip_attributes only: :phone, regex: /[^0-9]/
# Strip off all spaces and keep only alphabetic and numeric characters
strip_attributes only: :nickname, regex: /[^[:alnum:]_-]/
# Remove trailing whitespace from a multi-line string
strip_attributes only: :code, regex: /[[:blank:]]+$/)
end
Usage Patterns
Other ORMs implementing ActiveModel
It also works on other ActiveModel classes, such as Mongoid documents:
class User
include Mongoid::Document
strip_attributes only: :email
end
Using it with ActiveAttr
class Person
include ActiveAttr::Model
include ActiveModel::Validations::Callbacks
attribute :name
attribute :email
strip_attributes
end
Using it directly
# where record is an ActiveModel instance
StripAttributes.strip(record, collapse_spaces: true)
# works directly on Strings too
StripAttributes.strip(" foo \t") #=> "foo"
StripAttributes.strip(" foo bar", collapse_spaces: true) #=> "foo bar"
Testing
StripAttributes provides an RSpec/Shoulda-compatible matcher for easier testing of attribute assignment. You can use this with RSpec, Shoulda, Minitest-MatchersVaccine (preferred), or Minitest-Matchers.
Setup spec_helper.rb or test_helper.rb
To initialize RSpec, add this to your spec_helper.rb:
require "strip_attributes/matchers"
RSpec.configure do |config|
config.include StripAttributes::Matchers
end
To initialize Shoulda (with test-unit), add this to your test_helper.rb:
require "strip_attributes/matchers"
class Test::Unit::TestCase
extend StripAttributes::Matchers
end
OR if in a Rails environment, you might prefer this:
require "strip_attributes/matchers"
class ActiveSupport::TestCase
extend StripAttributes::Matchers
end
To initialize Minitest-MatchersVaccine, add this to your test_helper.rb:
require "strip_attributes/matchers"
class MiniTest::Spec
include StripAttributes::Matchers
end
OR if in a Rails environment, you might prefer this:
require "strip_attributes/matchers"
class ActiveSupport::TestCase
include StripAttributes::Matchers
end
To initialize Minitest-Matchers, add this to your test_helper.rb:
require "strip_attributes/matchers"
class MiniTest::Spec
include StripAttributes::Matchers
end
Writing Tests
RSpec:
describe User do
it { is_expected.to strip_attribute(:name).collapse_spaces }
it { is_expected.to strip_attribute(:name).replace_newlines }
it { is_expected.to strip_attribute :email }
it { is_expected.to strip_attributes(:name, :email) }
it { is_expected.not_to strip_attribute :password }
it { is_expected.not_to strip_attributes(:password, :encrypted_password) }
end
Shoulda (with test-unit):
class UserTest < ActiveSupport::TestCase
should strip_attribute(:name).collapse_spaces
should strip_attribute(:name).replace_newlines
should strip_attribute :email
should strip_attributes(:name, :email)
should_not strip_attribute :password
should_not strip_attributes(:password, :encrypted_password)
end
Minitest-MatchersVaccine:
describe User do
subject { User.new }
it "should strip attributes" do
must strip_attribute(:name).collapse_spaces
must strip_attribute(:name).replace_newlines
must strip_attribute :email
must strip_attributes(:name, :email)
wont strip_attribute :password
wont strip_attributes(:password, :encrypted_password)
end
end
Minitest-Matchers:
describe User do
subject { User.new }
must { strip_attribute(:name).collapse_spaces }
must { strip_attribute(:name).replace_newlines }
must { strip_attribute :email }
must { strip_attributes(:name, :email) }
wont { strip_attribute :password }
wont { strip_attributes(:password, :encrypted_password) }
end
Support
Submit suggestions or feature requests as a GitHub Issue or Pull Request (preferred). If you send a pull request, remember to update the corresponding unit tests. In fact, I prefer new features to be submitted in the form of new unit tests.
Credits
The idea was originally triggered by the information at the (now defunct) Rails Wiki but was modified from the original to include more idiomatic ruby and rails support.
Versioning
Semantic Versioning 2.0 as defined at http://semver.org.