The Attachment class manages the files for a given attachment. It saves when the model saves, deletes when the model is destroyed, and processes the file upon assignment.
# File lib/paperclip/attachment.rb, line 9 def self.default_options @default_options ||= { :convert_options => {}, :default_style => :original, :default_url => "/:attachment/:style/missing.png", :restricted_characters => %r[&$+,\/:;=?@<>\[\]\{\}\|\\\^~%# ]/, :hash_data => ":class/:attachment/:id/:style/:updated_at", :hash_digest => "SHA1", :interpolator => Paperclip::Interpolations, :only_process => [], :path => ":rails_root/public:url", :preserve_files => false, :processors => [:thumbnail], :source_file_options => {}, :storage => :filesystem, :styles => {}, :url => "/system/:class/:attachment/:id_partition/:style/:filename", :url_generator => Paperclip::UrlGenerator, :use_default_time_zone => true, :use_timestamp => true, :whiny => Paperclip.options[:whiny] || Paperclip.options[:whiny_thumbnails] } end
Creates an Attachment object.
name
is the name of the attachment, instance
is
the ActiveRecord object instance it’s attached to, and options
is the same as the hash passed to has_attached_file
.
Options include:
url
- a relative URL of the attachment. This is interpolated
using interpolator
path
- where on the filesystem
to store the attachment. This is interpolated using
interpolator
styles
- a hash of options for
processing the attachment. See has_attached_file
for the
details only_process
- style args to be run through the
post-processor. This defaults to the empty list default_url
-
a URL for the missing image default_style
- the style to use
when an argument is not specified e.g. url, path storage
- the
storage mechanism. Defaults to :filesystem use_timestamp
-
whether to append an anti-caching timestamp to image URLs. Defaults to true
whiny
, whiny_thumbnails
- whether to raise when
thumbnailing fails use_default_time_zone
- related to
use_timestamp
. Defaults to true hash_digest
- a
string representing a class that will be used to hash URLs for obfuscation
hash_data
- the relative URL for the hash data. This is
interpolated using interpolator
hash_secret
- a
secret passed to the hash_digest
convert_options
- flags passed to the convert
command for processing
source_file_options
- flags passed to the convert
command that controls how the file is read processors
-
classes that transform the attachment. Defaults to [:thumbnail]
preserve_files
- whether to keep files on the filesystem when
deleting or clearing the attachment. Defaults to false
interpolator
- the object used to interpolate filenames and
URLs. Defaults to Paperclip::Interpolations
url_generator
- the object used to generate URLs, using the
interpolator. Defaults to Paperclip::UrlGenerator
# File lib/paperclip/attachment.rb, line 62 def initialize(name, instance, options = {}) @name = name @instance = instance options = self.class.default_options.merge(options) @options = options @post_processing = true @queued_for_delete = [] @queued_for_write = {} @errors = {} @dirty = false @interpolator = options[:interpolator] @url_generator = options[:url_generator].new(self, @options) @source_file_options = options[:source_file_options] @whiny = options[:whiny] initialize_storage end
What gets called when you call instance.attachment = File. It clears errors, assigns attributes, and processes the file. It also queues up the previous file for deletion, to be flushed away on save of its host. In addition to form uploads, you can also assign another Paperclip attachment:
new_user.avatar = old_user.avatar
# File lib/paperclip/attachment.rb, line 88 def assign uploaded_file ensure_required_accessors! file = Paperclip.io_adapters.for(uploaded_file) @options[:only_process].map!(&:to_sym) self.clear(*@options[:only_process]) return nil if file.nil? @queued_for_write[:original] = file instance_write(:file_name, cleanup_filename(file.original_filename)) instance_write(:content_type, file.content_type.to_s.strip) instance_write(:file_size, file.size) instance_write(:fingerprint, file.fingerprint) if instance_respond_to?(:fingerprint) instance_write(:created_at, Time.now) if has_enabled_but_unset_created_at? instance_write(:updated_at, Time.now) @dirty = true post_process(*@options[:only_process]) if post_processing # Reset the file size if the original file was reprocessed. instance_write(:file_size, @queued_for_write[:original].size) instance_write(:fingerprint, @queued_for_write[:original].fingerprint) if instance_respond_to?(:fingerprint) end
Clears out the attachment. Has the same effect as previously assigning nil to the attachment. Does NOT save. If you wish to clear AND save, use destroy.
# File lib/paperclip/attachment.rb, line 208 def clear(*styles_to_clear) if styles_to_clear.any? queue_some_for_delete(*styles_to_clear) else queue_all_for_delete @queued_for_write = {} @errors = {} end end
Returns the #content_type of the file as originally assigned, and lives in the <attachment>_content_type attribute of the model.
# File lib/paperclip/attachment.rb, line 253 def content_type instance_read(:content_type) end
Returns the creation time of the file as originally assigned, and lives in the <attachment>_created_at attribute of the model.
# File lib/paperclip/attachment.rb, line 259 def created_at if able_to_store_created_at? time = instance_read(:created_at) time && time.to_f.to_i end end
Destroys the attachment. Has the same effect as previously assigning nil to the attachment *and saving*. This is permanent. If you wish to wipe out the existing attachment but not save, use clear.
# File lib/paperclip/attachment.rb, line 221 def destroy unless @options[:preserve_files] clear save end end
Returns true if there are changes that need to be saved.
# File lib/paperclip/attachment.rb, line 192 def dirty? @dirty end
Returns an array containing the errors on this attachment.
# File lib/paperclip/attachment.rb, line 187 def errors @errors end
Returns true if a file has been assigned.
# File lib/paperclip/attachment.rb, line 307 def file? !original_filename.blank? end
Returns the fingerprint of the file, if one’s defined. The fingerprint is stored in the <attachment>_fingerprint attribute of the model.
# File lib/paperclip/attachment.rb, line 247 def fingerprint instance_read(:fingerprint) end
Returns a unique hash suitable for obfuscating the URL of an otherwise publicly viewable attachment.
# File lib/paperclip/attachment.rb, line 281 def hash_key(style_name = default_style) raise ArgumentError, "Unable to generate hash without :hash_secret" unless @options[:hash_secret] require 'openssl' unless defined?(OpenSSL) data = interpolate(@options[:hash_data], style_name) OpenSSL::HMAC.hexdigest(OpenSSL::Digest.const_get(@options[:hash_digest]).new, @options[:hash_secret], data) end
Reads the attachment-specific attribute on the instance. See #instance_write for more details.
# File lib/paperclip/attachment.rb, line 331 def instance_read(attr) getter = :"#{name}_#{attr}" if instance.respond_to?(getter) instance.send(getter) end end
Determines whether the instance responds to this attribute. Used to prevent calculations on fields we won’t even store.
# File lib/paperclip/attachment.rb, line 315 def instance_respond_to?(attr) instance.respond_to?(:"#{name}_#{attr}") end
Writes the attachment-specific attribute on the instance. For example, #instance_write(:file_name, “me.jpg”) will write “me.jpg” to the instance’s “avatar_file_name” field (assuming the attachment is called avatar).
# File lib/paperclip/attachment.rb, line 322 def instance_write(attr, value) setter = :"#{name}_#{attr}=" if instance.respond_to?(setter) instance.send(setter, value) end end
Returns the name of the file as originally assigned, and lives in the <attachment>_file_name attribute of the model.
# File lib/paperclip/attachment.rb, line 235 def original_filename instance_read(:file_name) end
Returns the path of the attachment as defined by the :path option. If the file is stored in the filesystem the path refers to the path of the file on disk. If the file is stored in S3, the path is the “key” part of the URL, and the :bucket option refers to the S3 bucket.
# File lib/paperclip/attachment.rb, line 149 def path(style_name = default_style) path = original_filename.nil? ? nil : interpolate(path_option, style_name) path.respond_to?(:unescape) ? path.unescape : path end
# File lib/paperclip/attachment.rb, line 176 def processors processing_option = @options[:processors] if processing_option.respond_to?(:call) processing_option.call(instance) else processing_option end end
This method really shouldn’t be called that often. It’s expected use is in the paperclip:refresh rake task and that’s it. It will regenerate all thumbnails forcefully, by reobtaining the original file and going through the post-process again.
# File lib/paperclip/attachment.rb, line 292 def reprocess!(*style_args) saved_only_process, @options[:only_process] = @options[:only_process], style_args begin assign(self) save instance.save rescue Errno::EACCES => e warn "#{e} - skipping file." false ensure @options[:only_process] = saved_only_process end end
Saves the file, if there are no errors. If there are, it flushes them to the instance’s errors and returns false, cancelling the save.
# File lib/paperclip/attachment.rb, line 198 def save flush_deletes unless @options[:keep_old_files] flush_writes @dirty = false true end
Returns the size of the file as originally assigned, and lives in the <attachment>_file_size attribute of the model.
# File lib/paperclip/attachment.rb, line 241 def size instance_read(:file_size) || (@queued_for_write[:original] && @queued_for_write[:original].size) end
# File lib/paperclip/attachment.rb, line 163 def styles if @options[:styles].respond_to?(:call) || @normalized_styles.nil? styles = @options[:styles] styles = styles.call(self) if styles.respond_to?(:call) @normalized_styles = styles.dup styles.each_pair do |name, options| @normalized_styles[name.to_sym] = Paperclip::Style.new(name.to_sym, options.dup, self) end end @normalized_styles end
The time zone to use for timestamp interpolation. Using the default time zone ensures that results are consistent across all threads.
# File lib/paperclip/attachment.rb, line 275 def time_zone @options[:use_default_time_zone] ? Time.zone_default : Time.zone end
Alias to url
# File lib/paperclip/attachment.rb, line 155 def to_s style_name = default_style url(style_name) end
Returns the last modified time of the file as originally assigned, and lives in the <attachment>_updated_at attribute of the model.
# File lib/paperclip/attachment.rb, line 268 def updated_at time = instance_read(:updated_at) time && time.to_f.to_i end
Returns the uploaded file if present.
# File lib/paperclip/attachment.rb, line 229 def uploaded_file instance_read(:uploaded_file) end
Returns the public URL of the attachment with a given style. This does not necessarily need to point to a file that your Web server can access and can instead point to an action in your app, for example for fine grained security; this has a serious performance tradeoff.
Options:
timestamp
- Add a timestamp to the end of the URL. Default:
true. escape
- Perform URI escaping to the URL. Default:
true.
Global controls (set on has_attached_file):
interpolator
- The object that fills in a URL pattern's
variables. default_url
- The image to show when the
attachment has no image. url
- The URL for a saved
image. url_generator
- The object that generates a URL.
Default: Paperclip::UrlGenerator.
As mentioned just above, the object that generates this URL can be passed in, for finer control. This object must respond to two methods:
+new(Paperclip::Attachment, options_hash)+ +for(style_name, options_hash)+
# File lib/paperclip/attachment.rb, line 135 def url(style_name = default_style, options = {}) default_options = {:timestamp => @options[:use_timestamp], :escape => true} if options == true || options == false # Backwards compatibility. @url_generator.for(style_name, default_options.merge(:timestamp => options)) else @url_generator.for(style_name, default_options.merge(options)) end end