app/models/image.rb
class Image < ActiveRecord::Base
include ImagesHelper
include ImageablesHelper
TITLE_LENGTH_RANGE = 4..80
MIN_SIZE = 475
MAX_IMAGE_SIZE = 1.megabyte
ACCEPTED_CONTENT_TYPE = %w(image/jpeg image/jpg).freeze
has_attached_file :attachment, styles: { large: "x#{MIN_SIZE}", medium: "300x300#", thumb: "140x245#" },
url: "/system/:class/:prefix/:style/:hash.:extension",
hash_data: ":class/:style",
use_timestamp: false,
hash_secret: Rails.application.secrets.secret_key_base
attr_accessor :cached_attachment
belongs_to :user
belongs_to :imageable, polymorphic: true
# Disable paperclip security validation due to polymorphic configuration
# Paperclip do not allow to use Procs on valiations definition
do_not_validate_attachment_file_type :attachment
validate :attachment_presence
validate :validate_attachment_content_type, if: -> { attachment.present? }
validate :validate_attachment_size, if: -> { attachment.present? }
validates :title, presence: true, length: { in: TITLE_LENGTH_RANGE }
validates :user_id, presence: true
validates :imageable_id, presence: true, if: -> { persisted? }
validates :imageable_type, presence: true, if: -> { persisted? }
validate :validate_image_dimensions, if: -> { attachment.present? && attachment.dirty? }
before_save :set_attachment_from_cached_attachment, if: -> { cached_attachment.present? }
after_save :remove_cached_attachment, if: -> { cached_attachment.present? }
def set_cached_attachment_from_attachment
self.cached_attachment = if Paperclip::Attachment.default_options[:storage] == :filesystem
attachment.path
else
attachment.url
end
end
def set_attachment_from_cached_attachment
self.attachment = if Paperclip::Attachment.default_options[:storage] == :filesystem
File.open(cached_attachment)
else
URI.parse(cached_attachment)
end
end
Paperclip.interpolates :prefix do |attachment, style|
attachment.instance.prefix(attachment, style)
end
def prefix(attachment, _style)
if !attachment.instance.persisted?
"cached_attachments/user/#{attachment.instance.user_id}"
else
":attachment/:id_partition"
end
end
private
def imageable_class
imageable_type.constantize if imageable_type.present?
end
def validate_image_dimensions
if attachment_of_valid_content_type?
return true if imageable_class == Widget::Card
dimensions = Paperclip::Geometry.from_file(attachment.queued_for_write[:original].path)
errors.add(:attachment, :min_image_width, required_min_width: MIN_SIZE) if dimensions.width < MIN_SIZE
errors.add(:attachment, :min_image_height, required_min_height: MIN_SIZE) if dimensions.height < MIN_SIZE
end
end
def validate_attachment_size
if imageable_class &&
attachment_file_size > 1.megabytes
errors[:attachment] = I18n.t("images.errors.messages.in_between",
min: "0 Bytes",
max: "#{imageable_max_file_size} MB")
end
end
def validate_attachment_content_type
if imageable_class && !attachment_of_valid_content_type?
errors[:attachment] = I18n.t("images.errors.messages.wrong_content_type",
content_type: attachment_content_type,
accepted_content_types: imageable_humanized_accepted_content_types)
end
end
def attachment_presence
if attachment.blank? && cached_attachment.blank?
errors[:attachment] = I18n.t("errors.messages.blank")
end
end
def attachment_of_valid_content_type?
attachment.present? && imageable_accepted_content_types.include?(attachment_content_type)
end
def remove_cached_attachment
image = Image.new(imageable: imageable,
cached_attachment: cached_attachment,
user: user)
image.set_attachment_from_cached_attachment
image.attachment.destroy
end
end