Class: Paperclip::Thumbnail
- Defined in:
- lib/paperclip/thumbnail.rb
Overview
Handles thumbnailing images that are uploaded.
Constant Summary collapse
- ANIMATED_FORMATS =
List of formats that we need to preserve animation
%w(gif)
- MULTI_FRAME_FORMATS =
%w(.mkv .avi .mp4 .mov .mpg .mpeg .gif)
Instance Attribute Summary collapse
-
#animated ⇒ Object
Returns the value of attribute animated.
-
#auto_orient ⇒ Object
Returns the value of attribute auto_orient.
-
#convert_options ⇒ Object
Returns the value of attribute convert_options.
-
#current_geometry ⇒ Object
Returns the value of attribute current_geometry.
-
#format ⇒ Object
Returns the value of attribute format.
-
#frame_index ⇒ Object
Returns the value of attribute frame_index.
-
#source_file_options ⇒ Object
Returns the value of attribute source_file_options.
-
#target_geometry ⇒ Object
Returns the value of attribute target_geometry.
-
#whiny ⇒ Object
Returns the value of attribute whiny.
Attributes inherited from Processor
Instance Method Summary collapse
-
#convert_options? ⇒ Boolean
Returns true if the image is meant to make use of additional convert options.
-
#crop? ⇒ Boolean
Returns true if the
target_geometry
is meant to crop. -
#initialize(file, options = {}, attachment = nil) ⇒ Thumbnail
constructor
Creates a Thumbnail object set to work on the
file
given. -
#make ⇒ Object
Performs the conversion of the
file
into a thumbnail. -
#transformation_command ⇒ Object
Returns the command ImageMagick’s
convert
needs to transform the image into the thumbnail.
Methods inherited from Processor
Constructor Details
#initialize(file, options = {}, attachment = nil) ⇒ Thumbnail
Creates a Thumbnail object set to work on the file
given. It will attempt to transform the image into one defined by target_geometry
which is a “WxH”-style string. format
will be inferred from the file
unless specified. Thumbnail creation will raise no errors unless whiny
is true (which it is, by default. If convert_options
is set, the options will be appended to the convert command upon image conversion
Options include:
+geometry+ - the desired width and height of the thumbnail (required)
+file_geometry_parser+ - an object with a method named +from_file+ that takes an image file and produces its geometry and a +transformation_to+. Defaults to Paperclip::Geometry
+string_geometry_parser+ - an object with a method named +parse+ that takes a string and produces an object with +width+, +height+, and +to_s+ accessors. Defaults to Paperclip::Geometry
++ - flags passed to the +convert+ command that influence how the source file is read
++ - flags passed to the +convert+ command that influence how the image is processed
+whiny+ - whether to raise an error when processing fails. Defaults to true
+format+ - the desired filename extension
+animated+ - whether to merge all the layers in the image. Defaults to true
+frame_index+ - the frame index of the source file to render as the thumbnail
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# File 'lib/paperclip/thumbnail.rb', line 30 def initialize(file, = {}, = nil) super geometry = [:geometry].to_s @crop = geometry[-1,1] == '#' @target_geometry = .fetch(:string_geometry_parser, Geometry).parse(geometry) @current_geometry = .fetch(:file_geometry_parser, Geometry).from_file(@file) = [:source_file_options] = [:convert_options] @whiny = .fetch(:whiny, true) @format = [:format] @animated = .fetch(:animated, true) @auto_orient = .fetch(:auto_orient, true) if @auto_orient && @current_geometry.respond_to?(:auto_orient) @current_geometry.auto_orient end = .split(/\s+/) if .respond_to?(:split) = .split(/\s+/) if .respond_to?(:split) @current_format = File.extname(@file.path) @basename = File.basename(@file.path, @current_format) @frame_index = multi_frame_format? ? .fetch(:frame_index, 0) : 0 end |
Instance Attribute Details
#animated ⇒ Object
Returns the value of attribute animated.
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# File 'lib/paperclip/thumbnail.rb', line 5 def animated @animated end |
#auto_orient ⇒ Object
Returns the value of attribute auto_orient.
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# File 'lib/paperclip/thumbnail.rb', line 5 def auto_orient @auto_orient end |
#convert_options ⇒ Object
Returns the value of attribute convert_options.
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# File 'lib/paperclip/thumbnail.rb', line 5 def end |
#current_geometry ⇒ Object
Returns the value of attribute current_geometry.
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# File 'lib/paperclip/thumbnail.rb', line 5 def current_geometry @current_geometry end |
#format ⇒ Object
Returns the value of attribute format.
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# File 'lib/paperclip/thumbnail.rb', line 5 def format @format end |
#frame_index ⇒ Object
Returns the value of attribute frame_index.
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# File 'lib/paperclip/thumbnail.rb', line 5 def frame_index @frame_index end |
#source_file_options ⇒ Object
Returns the value of attribute source_file_options.
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# File 'lib/paperclip/thumbnail.rb', line 5 def end |
#target_geometry ⇒ Object
Returns the value of attribute target_geometry.
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# File 'lib/paperclip/thumbnail.rb', line 5 def target_geometry @target_geometry end |
#whiny ⇒ Object
Returns the value of attribute whiny.
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# File 'lib/paperclip/thumbnail.rb', line 5 def whiny @whiny end |
Instance Method Details
#convert_options? ⇒ Boolean
Returns true if the image is meant to make use of additional convert options.
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# File 'lib/paperclip/thumbnail.rb', line 60 def !.nil? && !.empty? end |
#crop? ⇒ Boolean
Returns true if the target_geometry
is meant to crop.
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# File 'lib/paperclip/thumbnail.rb', line 55 def crop? @crop end |
#make ⇒ Object
Performs the conversion of the file
into a thumbnail. Returns the Tempfile that contains the new image.
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# File 'lib/paperclip/thumbnail.rb', line 66 def make src = @file filename = [@basename, @format ? ".#{@format}" : ""].join dst = TempfileFactory.new.generate(filename) begin parameters = [] parameters << parameters << ":source" parameters << transformation_command parameters << parameters << ":dest" parameters = parameters.flatten.compact.join(" ").strip.squeeze(" ") frame = animated? ? "" : "[#{@frame_index}]" convert( parameters, source: "#{File.expand_path(src.path)}#{frame}", dest: File.(dst.path), ) rescue Terrapin::ExitStatusError => e if @whiny = "There was an error processing the thumbnail for #{@basename}:\n" + e. raise Paperclip::Error, end rescue Terrapin::CommandNotFoundError => e raise Paperclip::Errors::CommandNotFoundError.new("Could not run the `convert` command. Please install ImageMagick.") end dst end |
#transformation_command ⇒ Object
Returns the command ImageMagick’s convert
needs to transform the image into the thumbnail.
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# File 'lib/paperclip/thumbnail.rb', line 101 def transformation_command scale, crop = @current_geometry.transformation_to(@target_geometry, crop?) trans = [] trans << "-coalesce" if animated? trans << "-auto-orient" if auto_orient trans << "-resize" << %["#{scale}"] unless scale.nil? || scale.empty? trans << "-crop" << %["#{crop}"] << "+repage" if crop trans << '-layers "optimize"' if animated? trans end |