Module: Technoweenie::AttachmentFu::InstanceMethods

Defined in:
lib/technoweenie/attachment_fu.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.included(base) ⇒ Object 



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# File 'lib/technoweenie/attachment_fu.rb', line 251

def self.included(base)
  if base.respond_to?(:define_callbacks)
    base.class_eval do
      define_callbacks :resize, :attachment_saved, :kind => :after
      define_callbacks :thumbnail_saved, :kind => :before
    end
  end
end

Instance Method Details

#content_type=(new_type) ⇒ Object

Sets the content type.



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# File 'lib/technoweenie/attachment_fu.rb', line 303

def content_type=(new_type)
  write_attribute :content_type, new_type.to_s.strip
end

#copy_to_temp_file(file) ⇒ Object

Copies the given file to a randomly named Tempfile.



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# File 'lib/technoweenie/attachment_fu.rb', line 381

def copy_to_temp_file(file)
  self.class.copy_to_temp_file file, random_tempfile_filename
end

#create_or_update_thumbnail(temp_file, file_name_suffix, *size) ⇒ Object

Creates or updates the thumbnail for the current attachment.



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# File 'lib/technoweenie/attachment_fu.rb', line 288

def create_or_update_thumbnail(temp_file, file_name_suffix, *size)
  thumbnailable? || raise(ThumbnailError.new("Can't create a thumbnail if the content type is not an image or there is no parent_id column"))
  find_or_initialize_thumbnail(file_name_suffix).tap do |thumb|
    thumb.temp_paths.unshift temp_file
    thumb.send(:'attributes=', {
      :content_type             => content_type,
      :filename                 => thumbnail_name_for(file_name_suffix),
      :thumbnail_resize_options => size
    }, false)
    callback_with_args :before_thumbnail_saved, thumb
    thumb.save!
  end
end

#create_temp_file ⇒ Object

Stub for creating a temp file from the attachment data. This should be defined in the backend module.



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# File 'lib/technoweenie/attachment_fu.rb', line 391

def create_temp_file() end

#filename=(new_name) ⇒ Object

Sanitizes a filename.



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# File 'lib/technoweenie/attachment_fu.rb', line 308

def filename=(new_name)
  write_attribute :filename, sanitize_filename(new_name)
end

#image? ⇒ Boolean

Checks whether the attachment’s content type is an image content type

Returns:

  • (Boolean) 


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# File 'lib/technoweenie/attachment_fu.rb', line 261

def image?
  self.class.image?(content_type)
end

#image_size ⇒ Object

Returns the width/height in a suitable format for the image_tag helper: (100x100)



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# File 'lib/technoweenie/attachment_fu.rb', line 313

def image_size
  [width.to_s, height.to_s] * 'x'
end

#save_attachment? ⇒ Boolean

Returns true if the attachment data will be written to the storage system on the next save

Returns:

  • (Boolean) 


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# File 'lib/technoweenie/attachment_fu.rb', line 318

def save_attachment?
  File.file?(temp_path.to_s)
end

#set_temp_data(data) ⇒ Object

Writes the given data to a Tempfile and adds it to the collection of temp files.



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# File 'lib/technoweenie/attachment_fu.rb', line 376

def set_temp_data(data)
  temp_paths.unshift write_to_temp_file data unless data.nil?
end

#temp_data ⇒ Object

Gets the data from the latest temp file. This will read the file into memory.



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# File 'lib/technoweenie/attachment_fu.rb', line 371

def temp_data
  save_attachment? ? File.read(temp_path) : nil
end

#temp_path ⇒ Object

Gets the latest temp path from the collection of temp paths. While working with an attachment, multiple Tempfile objects may be created for various processing purposes (resizing, for example). An array of all the tempfile objects is stored so that the Tempfile instance is held on to until it’s not needed anymore. The collection is cleared after saving the attachment.



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# File 'lib/technoweenie/attachment_fu.rb', line 359

def temp_path
  p = temp_paths.first
  p.respond_to?(:path) ? p.path : p.to_s
end

#temp_paths ⇒ Object

Gets an array of the currently used temp paths. Defaults to a copy of #full_filename.



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# File 'lib/technoweenie/attachment_fu.rb', line 365

def temp_paths
  @temp_paths ||= (new_record? || !respond_to?(:full_filename) || !File.exist?(full_filename) ?
    [] : [copy_to_temp_file(full_filename)])
end

#thumbnail_class ⇒ Object

Returns the class used to create new thumbnails for this attachment.



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# File 'lib/technoweenie/attachment_fu.rb', line 271

def thumbnail_class
  self.class.thumbnail_class
end

#thumbnail_name_for(thumbnail = nil) ⇒ Object

Gets the thumbnail name for a filename. ‘foo.jpg’ becomes ‘foo_thumbnail.jpg’



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# File 'lib/technoweenie/attachment_fu.rb', line 276

def thumbnail_name_for(thumbnail = nil)
  return filename if thumbnail.blank?
  ext = nil
  basename = filename.gsub /\.\w+$/ do |s|
    ext = s; ''
  end
  # ImageScience doesn't create gif thumbnails, only pngs
  ext.sub!(/gif$/, 'png') if attachment_options[:processor] == "ImageScience"
  "#{basename}_#{thumbnail}#{ext}"
end

#thumbnailable? ⇒ Boolean

Returns true/false if an attachment is thumbnailable. A thumbnailable attachment has an image content type and the parent_id attribute.

Returns:

  • (Boolean) 


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# File 'lib/technoweenie/attachment_fu.rb', line 266

def thumbnailable?
  image? && respond_to?(:parent_id) && parent_id.nil?
end

#uploaded_data ⇒ Object

nil placeholder in case this field is used in a form.



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# File 'lib/technoweenie/attachment_fu.rb', line 323

def uploaded_data() nil; end

#uploaded_data=(file_data) ⇒ Object

This method handles the uploaded file object. If you set the field name to uploaded_data, you don’t need any special code in your controller.

<% form_for :attachment, :html => { :multipart => true } do |f| -%>
  <p><%= f.file_field :uploaded_data %></p>
  <p><%= submit_tag :Save %>
<% end -%>

@attachment = Attachment.create! params[:attachment]

TODO: Allow it to work with Merb tempfiles too.



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# File 'lib/technoweenie/attachment_fu.rb', line 336

def uploaded_data=(file_data)
  if file_data.respond_to?(:content_type)
    return nil if file_data.size == 0
    self.content_type = file_data.content_type
    self.filename     = file_data.original_filename if respond_to?(:filename)
  else
    return nil if file_data.blank? || file_data['size'] == 0
    self.content_type = file_data['content_type']
    self.filename =  file_data['filename']
    file_data = file_data['tempfile']
  end
  if file_data.is_a?(StringIO)
    file_data.rewind
    set_temp_data file_data.read
  else
    self.temp_paths.unshift file_data
  end
end

#with_image(&block) ⇒ Object

Allows you to work with a processed representation (RMagick, ImageScience, etc) of the attachment in a block.

@attachment.with_image do |img|
  self.data = img.thumbnail(100, 100).to_blob
end



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# File 'lib/technoweenie/attachment_fu.rb', line 399

def with_image(&block)
  self.class.with_image(temp_path, &block)
end

#write_to_temp_file(data) ⇒ Object

Writes the given file to a randomly named Tempfile.



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# File 'lib/technoweenie/attachment_fu.rb', line 386

def write_to_temp_file(data)
  self.class.write_to_temp_file data, random_tempfile_filename
end