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 212

def self.included(base)
  base.define_callbacks *[:after_resize, :after_attachment_saved, :before_thumbnail_saved] if base.respond_to?(:define_callbacks)
end

Instance Method Details

#content_type=(new_type) ⇒ Object

Sets the content type.



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# File 'lib/technoweenie/attachment_fu.rb', line 259

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 338

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 244

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"))
  returning find_or_initialize_thumbnail(file_name_suffix) do |thumb|
    thumb.attributes = {
      :content_type             => content_type,
      :filename                 => thumbnail_name_for(file_name_suffix),
      :temp_path                => temp_file,
      :thumbnail_resize_options => size
    }
    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 348

def create_temp_file() end

#filename=(new_name) ⇒ Object

Sanitizes a filename.



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# File 'lib/technoweenie/attachment_fu.rb', line 264

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 217

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 269

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 274

def save_attachment?
  File.file?(temp_path.to_s)
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 328

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

#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 333

def temp_data=(data)
  self.temp_path = write_to_temp_file data unless data.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 308

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

#temp_path=(value) ⇒ Object

Adds a new temp_path to the array. This should take a string or a Tempfile. This class makes no attempt to remove the files, so Tempfiles should be used. Tempfiles remove themselves when they go out of scope. You can also use string paths for temporary files, such as those used for uploaded files in a web server.



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# File 'lib/technoweenie/attachment_fu.rb', line 322

def temp_path=(value)
  temp_paths.unshift value
  temp_path
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 314

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 227

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 232

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 222

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 279

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 292

def uploaded_data=(file_data)
  return nil if file_data.nil? || file_data.size == 0
  self.content_type = file_data.content_type
  self.filename     = file_data.original_filename if respond_to?(:filename)
  if file_data.is_a?(StringIO)
    file_data.rewind
    self.temp_data = file_data.read
  else
    self.temp_path = 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 356

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 343

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