Class: Paperclip::Attachment

Inherits:
Object
  • Object
show all
Includes:
IOStream
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

Methods included from IOStream

#stream_to, #to_tempfile

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



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# File 'lib/paperclip/attachment.rb', line 59

def initialize name, instance, options = {}
  @name              = name
  @instance          = instance

  options = self.class.default_options.merge(options)

  @options               = Paperclip::Options.new(self, options)
  @post_processing       = true
  @queued_for_delete     = []
  @queued_for_write      = {}
  @errors                = {}
  @dirty                 = false
  @interpolator          = (options[:interpolator] || Paperclip::Interpolations)

  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 32

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 32

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 32

def instance
  @instance
end

#interpolator ⇒ Object (readonly)

Returns the value of attribute interpolator.



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# File 'lib/paperclip/attachment.rb', line 32

def interpolator
  @interpolator
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/paperclip/attachment.rb', line 32

def name
  @name
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/paperclip/attachment.rb', line 32

def options
  @options
end

#post_processing ⇒ Object

Returns the value of attribute post_processing.



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# File 'lib/paperclip/attachment.rb', line 33

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 32

def queued_for_write
  @queued_for_write
end

#whiny ⇒ Object (readonly)

Returns the value of attribute whiny.



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# File 'lib/paperclip/attachment.rb', line 32

def whiny
  @whiny
end

Class Method Details

.default_options ⇒ Object 



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# File 'lib/paperclip/attachment.rb', line 11

def self.default_options
  @default_options ||= {
    :url                   => "/system/:attachment/:id/:style/:filename",
    :path                  => ":rails_root/public:url",
    :styles                => {},
    :only_process          => [],
    :processors            => [:thumbnail],
    :convert_options       => {},
    :source_file_options   => {},
    :default_url           => "/:attachment/:style/missing.png",
    :default_style         => :original,
    :storage               => :filesystem,
    :use_timestamp         => true,
    :whiny                 => Paperclip.options[:whiny] || Paperclip.options[:whiny_thumbnails],
    :use_default_time_zone => true,
    :hash_digest           => "SHA1",
    :hash_data             => ":class/:attachment/:id/:style/:updated_at",
    :preserve_files        => false
  }
end

.interpolations ⇒ Object

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.



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# File 'lib/paperclip/attachment.rb', line 260

def self.interpolations
  warn('[DEPRECATION] Paperclip::Attachment.interpolations is deprecated ' +
       'and will be removed from future versions. ' +
       'Use Paperclip.interpolates instead')
  Paperclip::Interpolations
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 90

def assign uploaded_file
  ensure_required_accessors!

  if uploaded_file.is_a?(Paperclip::Attachment)
    uploaded_filename = uploaded_file.original_filename
    uploaded_file = uploaded_file.to_file(:original)
    close_uploaded_file = uploaded_file.respond_to?(:close)
  end

  return nil unless valid_assignment?(uploaded_file)

  uploaded_file.binmode if uploaded_file.respond_to? :binmode
  self.clear

  return nil if uploaded_file.nil?

  uploaded_filename ||= uploaded_file.original_filename
  @queued_for_write[:original]   = to_tempfile(uploaded_file)
  instance_write(:file_name,       uploaded_filename.strip)
  instance_write(:content_type,    uploaded_file.content_type.to_s.strip)
  instance_write(:file_size,       uploaded_file.size.to_i)
  instance_write(:fingerprint,     generate_fingerprint(uploaded_file))
  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.to_i)
  instance_write(:fingerprint, generate_fingerprint(@queued_for_write[:original]))
ensure
  uploaded_file.close if close_uploaded_file
end

#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 183

def clear
  queue_existing_for_delete
  @queued_for_write  = {}
  @errors            = {}
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 219

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 192

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 167

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 162

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 295

def file?
  !original_filename.blank?
end

#fingerprint ⇒ Object

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



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# File 'lib/paperclip/attachment.rb', line 213

def fingerprint
  instance_read(:fingerprint) || (@queued_for_write[:original] && generate_fingerprint(@queued_for_write[:original]))
end

#generate_fingerprint(source) ⇒ Object 



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# File 'lib/paperclip/attachment.rb', line 245

def generate_fingerprint(source)
  if source.respond_to?(:path) && source.path && !source.path.blank?
    Digest::MD5.file(source.path).to_s
  else
    data = source.read
    source.rewind if source.respond_to?(:rewind)
    Digest::MD5.hexdigest(data)
  end
end

#hash(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 238

def hash(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 313

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_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 304

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 201

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 143

def path(style_name = default_style)
  path = original_filename.nil? ? nil : interpolate(@options.path, style_name)
  path.respond_to?(:unescape) ? path.unescape : path
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 271

def reprocess!(*style_args)
  new_original = Tempfile.new("paperclip-reprocess")
  new_original.binmode
  if old_original = to_file(:original)
    new_original.write( old_original.respond_to?(:get) ? old_original.get : old_original.read )
    new_original.rewind

    @queued_for_write = { :original => new_original }
    instance_write(:updated_at, Time.now)
    post_process(*style_args)

    old_original.close if old_original.respond_to?(:close)
    old_original.unlink if old_original.respond_to?(:unlink)

    save
  else
    true
  end
rescue Errno::EACCES => e
  warn "#{e} - skipping file"
  false
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 173

def save
  flush_deletes
  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 207

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 157

def styles
  @options.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 232

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 149

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 225

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

#url(style_name = default_style, use_timestamp = @options.use_timestamp) ⇒ Object

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



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# File 'lib/paperclip/attachment.rb', line 131

def url(style_name = default_style, use_timestamp = @options.use_timestamp)
  default_url = @options.default_url.is_a?(Proc) ? @options.default_url.call(self) : @options.default_url
  url = original_filename.nil? ? interpolate(default_url, style_name) : interpolate(@options.url, style_name)

  url << (url.include?("?") ? "&" : "?") + updated_at.to_s if use_timestamp && updated_at
  url.respond_to?(:escape) ? url.escape : URI.escape(url)
end