Class: Platforms::ProductValidator

Inherits:
ActiveModel::EachValidator
  • Object
show all
Defined in:
app/validators/platforms/product_validator.rb

Overview

Checks if a record includes an attribute with value blah, and the Platforms::Blah namespace includes a class which inherits from Rails::Engine. That is usually called Platforms::Blah::Engine.

Adds a validation error if:

  • Platforms::Blah does not exist

  • Platforms::Blah does not have a class that inherits from Rails::Engine

Instance Method Summary collapse

Instance Method Details

#validate_each(record, attribute, value) ⇒ Object

Validate record includes an attribute with the value of a known Engine.

Checks if a record includes an attribute with value blah, and the Platforms::Blah namespace includes a class which inherits from Rails::Engine. That is usually called Platforms::Blah::Engine.

If Platforms::Blah does not include a known Engine, add an error.

Also requires that value is lowercase.

Parameters:

  • record (ActiveModel) —

    being validated

  • attribute (Symbol) —

    name of record

  • value (Object) —

    of record.attribute

Returns:

  • no suitable return value, just adds errors to record.



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# File 'app/validators/platforms/product_validator.rb', line 27

def validate_each(record, attribute, value)
  return if value.blank?

  unless value == value.downcase
    record.errors.add(attribute, "should be lower case")
    return
  end

  kamel = value.camelize

  begin
    klass = Platforms.const_get(kamel)
    children = klass.constants(false)
    children.select! do |k|
      # Do not allow non-Class looking things like String constants
      next unless klass.const_get(k).respond_to? :ancestors
      klass.const_get(k).ancestors.include? Rails::Engine
    end
    unless children.length == 1
      record.errors.add(attribute, "Platforms::#{kamel} is not a Rails::Engine")
    end
  rescue NameError => e
    record.errors.add(attribute, e)
    return
  end
end