Initial commit

app/validators/attached_validator.rb

@@ -0,0 +1,5 @@
+class AttachedValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    record.errors.add(attribute, :attached, options) unless value.attached?
+  end
+end

app/validators/content_type_validator.rb

@@ -0,0 +1,17 @@
+class ContentTypeValidator < ActiveModel::EachValidator
+  def validate_each(record, attribute, value)
+    return if !value.attached?
+
+    Array.wrap(value).each do |attachment|
+      if !attachment.content_type.in?(content_types)
+        record.errors.add(attribute, :content_type, options)
+      end
+    end
+  end
+
+  private
+
+  def content_types
+    options.fetch(:in)
+  end
+end

app/validators/email_validator.rb

@@ -0,0 +1,9 @@
+class EmailValidator < ActiveModel::EachValidator
+  EMAIL_REGEX = /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/i
+
+  def validate_each(record, attribute, value)
+    unless value =~ EMAIL_REGEX
+      record.errors[attribute] << (options[:message] || "is not an email")
+    end
+  end
+end