Class: Paperclip::Attachment

Inherits:
Object
  • Object
show all
Defined in:
lib/paperclip/attachment.rb

Overview

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.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, instance, options = {}) ⇒ Attachment

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 don’t specify an argument to 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 to 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



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# File 'lib/paperclip/attachment.rb', line 63

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

Instance Attribute Details

#convert_options ⇒ Object (readonly)

Returns the value of attribute convert_options.



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# File 'lib/paperclip/attachment.rb', line 34

def convert_options
  @convert_options
end

#default_style ⇒ Object (readonly)

Returns the value of attribute default_style.



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# File 'lib/paperclip/attachment.rb', line 34

def default_style
  @default_style
end

#instance ⇒ Object (readonly)

Returns the value of attribute instance.



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# File 'lib/paperclip/attachment.rb', line 34

def instance
  @instance
end

#interpolator ⇒ Object (readonly)

Returns the value of attribute interpolator.



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# File 'lib/paperclip/attachment.rb', line 34

def interpolator
  @interpolator
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/paperclip/attachment.rb', line 34

def name
  @name
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/paperclip/attachment.rb', line 34

def options
  @options
end

#post_processing ⇒ Object

Returns the value of attribute post_processing.



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# File 'lib/paperclip/attachment.rb', line 36

def post_processing
  @post_processing
end

#queued_for_write ⇒ Object (readonly)

Returns the value of attribute queued_for_write.



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# File 'lib/paperclip/attachment.rb', line 34

def queued_for_write
  @queued_for_write
end

#source_file_options ⇒ Object (readonly)

Returns the value of attribute source_file_options.



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# File 'lib/paperclip/attachment.rb', line 34

def source_file_options
  @source_file_options
end

#whiny ⇒ Object (readonly)

Returns the value of attribute whiny.



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# File 'lib/paperclip/attachment.rb', line 34

def whiny
  @whiny
end

Class Method Details

.default_options ⇒ Object 



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# File 'lib/paperclip/attachment.rb', line 10

def self.default_options
  @default_options ||= {
    :convert_options       => {},
    :default_style         => :original,
    :default_url           => "/:attachment/:style/missing.png",
    :restricted_characters => /[&$+,\/:;=?@<>\[\]\{\}\|\\\^~%# ]/,
    :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

Instance Method Details

#assign(uploaded_file) ⇒ Object

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



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# File 'lib/paperclip/attachment.rb', line 89

def assign uploaded_file
  ensure_required_accessors!
  file = Paperclip.io_adapters.for(uploaded_file)

  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(: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

#clear(*styles_to_clear) ⇒ Object

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.



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# File 'lib/paperclip/attachment.rb', line 205

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

#content_type ⇒ Object

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



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# File 'lib/paperclip/attachment.rb', line 250

def content_type
  instance_read(:content_type)
end

#destroy ⇒ Object

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.



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# File 'lib/paperclip/attachment.rb', line 218

def destroy
  unless @options[:preserve_files]
    clear
    save
  end
end

#dirty? ⇒ Boolean

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

Returns:

  • (Boolean) 


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# File 'lib/paperclip/attachment.rb', line 189

def dirty?
  @dirty
end

#errors ⇒ Object

Returns an array containing the errors on this attachment.



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# File 'lib/paperclip/attachment.rb', line 184

def errors
  @errors
end

#file? ⇒ Boolean Also known as: present?

Returns true if a file has been assigned.

Returns:

  • (Boolean) 


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# File 'lib/paperclip/attachment.rb', line 294

def file?
  !original_filename.blank?
end

#fingerprint ⇒ Object

Returns the fingerprint of the file, if one’s defined. The fingerprint is stored in the <attachment>_fingerpring attribute of the model.



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# File 'lib/paperclip/attachment.rb', line 244

def fingerprint
  instance_read(:fingerprint)
end

#hash_key(style_name = default_style) ⇒ Object

Returns a unique hash suitable for obfuscating the URL of an otherwise publicly viewable attachment.

Raises:

  • (ArgumentError) 


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# File 'lib/paperclip/attachment.rb', line 269

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

#instance_read(attr) ⇒ Object

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



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# File 'lib/paperclip/attachment.rb', line 318

def instance_read(attr)
  getter = :"#{name}_#{attr}"
  responds = instance.respond_to?(getter)
  cached = self.instance_variable_get("@_#{getter}")
  return cached if cached
  instance.send(getter) if responds || attr.to_s == "file_name"
end

#instance_respond_to?(attr) ⇒ Boolean

Determines whether the instance responds to this attribute. Used to prevent calculations on fields we won’t even store.

Returns:

  • (Boolean) 


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# File 'lib/paperclip/attachment.rb', line 302

def instance_respond_to?(attr)
  instance.respond_to?(:"#{name}_#{attr}")
end

#instance_write(attr, value) ⇒ Object

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).



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# File 'lib/paperclip/attachment.rb', line 309

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

#original_filename ⇒ Object

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



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# File 'lib/paperclip/attachment.rb', line 232

def original_filename
  instance_read(:file_name)
end

#path(style_name = default_style) ⇒ Object

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.



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# File 'lib/paperclip/attachment.rb', line 148

def path(style_name = default_style)
  path = original_filename.nil? ? nil : interpolate(path_option, style_name)
  path.respond_to?(:unescape) ? path.unescape : path
end

#processors ⇒ Object 



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# File 'lib/paperclip/attachment.rb', line 173

def processors
  processing_option = @options[:processors]

  if processing_option.respond_to?(:call)
    processing_option.call(instance)
  else
    processing_option
  end
end

#reprocess!(*style_args) ⇒ Object

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.



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# File 'lib/paperclip/attachment.rb', line 280

def reprocess!(*style_args)
  saved_only_process, @options[:only_process] = @options[:only_process], style_args
  begin
    assign(self)
    save
  rescue Errno::EACCES => e
    warn "#{e} - skipping file."
    false
  ensure
    @options[:only_process] = saved_only_process
  end
end

#save ⇒ Object

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.



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# File 'lib/paperclip/attachment.rb', line 195

def save
  flush_deletes unless @options[:keep_old_files]
  flush_writes
  @dirty = false
  true
end

#size ⇒ Object

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



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# File 'lib/paperclip/attachment.rb', line 238

def size
  instance_read(:file_size) || (@queued_for_write[:original] && @queued_for_write[:original].size)
end

#styles ⇒ Object 



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# File 'lib/paperclip/attachment.rb', line 162

def styles
  styling_option = @options[:styles]
  if styling_option.respond_to?(:call) || !@normalized_styles
    @normalized_styles = ActiveSupport::OrderedHash.new
    (styling_option.respond_to?(:call) ? styling_option.call(self) : styling_option).each do |name, args|
      @normalized_styles[name] = Paperclip::Style.new(name, args.dup, self)
    end
  end
  @normalized_styles
end

#time_zone ⇒ Object

The time zone to use for timestamp interpolation. Using the default time zone ensures that results are consistent across all threads.



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# File 'lib/paperclip/attachment.rb', line 263

def time_zone
  @options[:use_default_time_zone] ? Time.zone_default : Time.zone
end

#to_s(style_name = default_style) ⇒ Object

Alias to url



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# File 'lib/paperclip/attachment.rb', line 154

def to_s style_name = default_style
  url(style_name)
end

#updated_at ⇒ Object

Returns the last modified time of the file as originally assigned, and lives in the <attachment>_updated_at attribute of the model.



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# File 'lib/paperclip/attachment.rb', line 256

def updated_at
  time = instance_read(:updated_at)
  time && time.to_f.to_i
end

#uploaded_file ⇒ Object

Returns the uploaded file if present.



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# File 'lib/paperclip/attachment.rb', line 226

def uploaded_file
  instance_read(:uploaded_file)
end

#url(style_name = default_style, options = {}) ⇒ Object

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)



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# File 'lib/paperclip/attachment.rb', line 134

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