Class: Paperclip::Attachment

Class

Paperclip::Attachment

In:

lib/paperclip/attachment.rb

Parent:

Object

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.

Included Modules

IOStream

Attributes

 convert_options
 default_style
 instance
 name
 options
 queued_for_write
 whiny

Public Class methods

default_options()

    # File lib/paperclip/attachment.rb, line 9
 9:     def self.default_options
10:       @default_options ||= {
11:         :url               => "/system/:attachment/:id/:style/:filename",
12:         :path              => ":rails_root/public:url",
13:         :styles            => {},
14:         :processors        => [:thumbnail],
15:         :convert_options   => {},
16:         :default_url       => "/:attachment/:style/missing.png",
17:         :default_style     => :original,
18:         :storage           => :filesystem,
19:         :use_timestamp     => true,
20:         :whiny             => Paperclip.options[:whiny] || Paperclip.options[:whiny_thumbnails]
21:       }
22:     end

interpolations()

Paths and URLs can have a number of variables interpolated into them to vary the storage location based on name, id, style, class, etc. This method is a deprecated access into supplying and retrieving these interpolations. Future access should use either Paperclip.interpolates or extend the Paperclip::Interpolations module directly.

     # File lib/paperclip/attachment.rb, line 211
211:     def self.interpolations
212:       warn('[DEPRECATION] Paperclip::Attachment.interpolations is deprecated ' +
213:            'and will be removed from future versions. ' +
214:            'Use Paperclip.interpolates instead')
215:       Paperclip::Interpolations
216:     end

new(name, instance, options = {})

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.

    # File lib/paperclip/attachment.rb, line 29
29:     def initialize name, instance, options = {}
30:       @name              = name
31:       @instance          = instance
32: 
33:       options = self.class.default_options.merge(options)
34: 
35:       @url               = options[:url]
36:       @url               = @url.call(self) if @url.is_a?(Proc)
37:       @path              = options[:path]
38:       @path              = @path.call(self) if @path.is_a?(Proc)
39:       @styles            = options[:styles]
40:       @normalized_styles = nil
41:       @default_url       = options[:default_url]
42:       @default_style     = options[:default_style]
43:       @storage           = options[:storage]
44:       @use_timestamp     = options[:use_timestamp]
45:       @whiny             = options[:whiny_thumbnails] || options[:whiny]
46:       @convert_options   = options[:convert_options]
47:       @processors        = options[:processors]
48:       @options           = options
49:       @queued_for_delete = []
50:       @queued_for_write  = {}
51:       @errors            = {}
52:       @dirty             = false
53: 
54:       initialize_storage
55:     end

Public Instance methods

assign(uploaded_file)

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 77
 77:     def assign uploaded_file
 78:       ensure_required_accessors!
 79: 
 80:       if uploaded_file.is_a?(Paperclip::Attachment)
 81:         uploaded_file = uploaded_file.to_file(:original)
 82:         close_uploaded_file = uploaded_file.respond_to?(:close)
 83:       end
 84: 
 85:       return nil unless valid_assignment?(uploaded_file)
 86: 
 87:       uploaded_file.binmode if uploaded_file.respond_to? :binmode
 88:       self.clear
 89: 
 90:       return nil if uploaded_file.nil?
 91: 
 92:       @queued_for_write[:original]   = to_tempfile(uploaded_file)
 93:       instance_write(:file_name,       uploaded_file.original_filename.strip)
 94:       instance_write(:content_type,    uploaded_file.content_type.to_s.strip)
 95:       instance_write(:file_size,       uploaded_file.size.to_i)
 96:       instance_write(:fingerprint,     generate_fingerprint(uploaded_file))
 97:       instance_write(:updated_at,      Time.now)
 98: 
 99:       @dirty = true
100: 
101:       post_process
102: 
103:       # Reset the file size if the original file was reprocessed.
104:       instance_write(:file_size,   @queued_for_write[:original].size.to_i)
105:       instance_write(:fingerprint, generate_fingerprint(@queued_for_write[:original]))
106:     ensure
107:       uploaded_file.close if close_uploaded_file
108:     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 156
156:     def clear
157:       queue_existing_for_delete
158:       @errors            = {}
159:     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 189
189:     def content_type
190:       instance_read(:content_type)
191:     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 164
164:     def destroy
165:       clear
166:       save
167:     end

Returns true if there are changes that need to be saved.

     # File lib/paperclip/attachment.rb, line 140
140:     def dirty?
141:       @dirty
142:     end

Returns an array containing the errors on this attachment.

     # File lib/paperclip/attachment.rb, line 135
135:     def errors
136:       @errors
137:     end

Returns true if a file has been assigned.

     # File lib/paperclip/attachment.rb, line 241
241:     def file?
242:       !original_filename.blank?
243:     end

Returns the hash of the file as originally assigned, and lives in the <attachment>_fingerprint attribute of the model.

     # File lib/paperclip/attachment.rb, line 183
183:     def fingerprint
184:       instance_read(:fingerprint) || (@queued_for_write[:original] && generate_fingerprint(@queued_for_write[:original]))
185:     end

generate_fingerprint(source)

     # File lib/paperclip/attachment.rb, line 200
200:     def generate_fingerprint(source)
201:       data = source.read
202:       source.rewind if source.respond_to?(:rewind)
203:       Digest::MD5.hexdigest(data)
204:     end

instance_read(attr)

Reads the attachment-specific attribute on the instance. See instance_write for more details.

     # File lib/paperclip/attachment.rb, line 257
257:     def instance_read(attr)
258:       getter = "#{name}_#{attr}""#{name}_#{attr}"
259:       responds = instance.respond_to?(getter)
260:       cached = self.instance_variable_get("@_#{getter}")
261:       return cached if cached
262:       instance.send(getter) if responds || attr.to_s == "file_name"
263:     end

instance_write(attr, value)

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 248
248:     def instance_write(attr, value)
249:       setter = "#{name}_#{attr}=""#{name}_#{attr}="
250:       responds = instance.respond_to?(setter)
251:       self.instance_variable_set("@_#{setter.to_s.chop}", value)
252:       instance.send(setter, value) if responds || attr.to_s == "file_name"
253:     end

original_filename()

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 171
171:     def original_filename
172:       instance_read(:file_name)
173:     end

path(style_name = default_style)

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 125
125:     def path style_name = default_style
126:       original_filename.nil? ? nil : interpolate(@path, style_name)
127:     end

    # File lib/paperclip/attachment.rb, line 67
67:     def processors
68:       @processors.respond_to?(:call) ? @processors.call(instance) : @processors
69:     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 222
222:     def reprocess!
223:       new_original = Tempfile.new("paperclip-reprocess")
224:       new_original.binmode
225:       if old_original = to_file(:original)
226:         new_original.write( old_original.respond_to?(:get) ? old_original.get : old_original.read )
227:         new_original.rewind
228: 
229:         @queued_for_write = { :original => new_original }
230:         post_process
231: 
232:         old_original.close if old_original.respond_to?(:close)
233: 
234:         save
235:       else
236:         true
237:       end
238:     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 146
146:     def save
147:       flush_deletes
148:       flush_writes
149:       @dirty = false
150:       true
151:     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 177
177:     def size
178:       instance_read(:file_size) || (@queued_for_write[:original] && @queued_for_write[:original].size)
179:     end

    # File lib/paperclip/attachment.rb, line 57
57:     def styles
58:       unless @normalized_styles
59:         @normalized_styles = {}
60:         (@styles.respond_to?(:call) ? @styles.call(self) : @styles).each do |name, args|
61:           @normalized_styles[name] = Paperclip::Style.new(name, args.dup, self)
62:         end
63:       end
64:       @normalized_styles
65:     end

to_s(style_name = nil)

Alias to url

     # File lib/paperclip/attachment.rb, line 130
130:     def to_s style_name = nil
131:       url(style_name)
132:     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 195
195:     def updated_at
196:       time = instance_read(:updated_at)
197:       time && time.to_f.to_i
198:     end

url(style_name = default_style, use_timestamp = @use_timestamp)

Returns the public URL of the attachment, with a given style. Note that this does not necessarily need to point to a file that your web server can access and can point to an action in your app, if you need fine grained security. This is not recommended if you don‘t need the security, however, for performance reasons. Set use_timestamp to false if you want to stop the attachment update time appended to the url

     # File lib/paperclip/attachment.rb, line 116
116:     def url(style_name = default_style, use_timestamp = @use_timestamp)
117:       url = original_filename.nil? ? interpolate(@default_url, style_name) : interpolate(@url, style_name)
118:       use_timestamp && updated_at ? [url, updated_at].compact.join(url.include?("?") ? "&" : "?") : url
119:     end