Embedded file support for Prawn documents

lib/prawn.rb

@@ -61,6 +61,7 @@ def verify_options(accepted, actual)
 require_relative 'prawn/images/image'
 require_relative 'prawn/images/jpg'
 require_relative 'prawn/images/png'
+require_relative 'prawn/embedded_files'
 require_relative 'prawn/stamp'
 require_relative 'prawn/soft_mask'
 require_relative 'prawn/security'

lib/prawn/document.rb

@@ -55,6 +55,7 @@ class Document
  include Prawn::Text
  include Prawn::Graphics
  include Prawn::Images
+ include Prawn::EmbeddedFiles
  include Prawn::Stamp
  include Prawn::SoftMask
  include Prawn::TransformationStack

lib/prawn/embedded_files.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+module Prawn
+ module EmbeddedFiles
+ # include PDF::Core::EmbeddedFiles
+ # Link to PR (https://github.com/prawnpdf/pdf-core/pull/47)
+
+ def file(src, options = {})
+ path = Pathname.new(src)
+ mut_opts = options.dup
+
+ if path.directory?
+ raise ArgumentError, 'Data source can\'t be a directory'
+ elsif path.file?
+ data = path.read
+ mut_opts[:name] ||= src
+ mut_opts[:creation_date] ||= path.birthtime
+ mut_opts[:modification_date] ||= path.mtime
+ else
+ data = src
+ end
+
+ @file_registry ||= {}
+
+ file = EmbeddedFile.new(data, mut_opts)
+ file_obj = @file_registry[file.checksum]
+
+ if file_obj.nil?
+ file_obj = file.build_pdf_object(self)
+ @file_registry[file.checksum] = file_obj
+ end
+
+ filespec = Filespec.new(file_obj, mut_opts)
+ filespec_obj = filespec.build_pdf_object(self)
+
+ unless filespec.hidden?
+ # Wait for pdf-core PR
+
+ # attach_file(filespec.file_name, filespec_obj)
+ end
+ end
+ end
+end
+
+require_relative 'embedded_files/embedded_file'
+require_relative 'embedded_files/filespec'

lib/prawn/embedded_files/embedded_file.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require 'digest/md5'
+
+module Prawn
+ module EmbeddedFiles
+ class EmbeddedFile
+ attr_reader :checksum
+
+ def initialize(data, options = {})
+ @creation_date = options[:creation_date]
+ unless @creation_date.kind_of?(Time)
+ @creation_date = Time.now.utc
+ end
+
+ @modification_date = options[:modification_date]
+ unless @modification_date.kind_of?(Time)
+ @modification_date = Time.now.utc
+ end
+
+ @checksum = Digest::MD5.digest(data)
+ @data = data
+ end
+
+ def build_pdf_object(document)
+ obj = document.ref!(
+ Type: :EmbeddedFile,
+ Params: {
+ CreationDate: creation_date,
+ ModDate: modification_date,
+ CheckSum: PDF::Core::LiteralString.new(checksum),
+ Size: data.length
+ }
+ )
+
+ obj << data
+ obj.stream.compress! if document.compression_enabled?
+ obj
+ end
+
+ private
+
+ attr_reader :data, :creation_date, :modification_date
+ end
+ end
+end

lib/prawn/embedded_files/filespec.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+module Prawn
+ module EmbeddedFiles
+ class Filespec
+ attr_reader :file_name
+
+ def initialize(file, options = {})
+ name = options[:name] || file.checksum
+
+ @file_name = PDF::Core::LiteralString.new(name)
+
+ if options[:description]
+ desc_str = options[:description].to_s
+ @description = PDF::Core::LiteralString.new(desc_str)
+ end
+
+ @hidden = options[:hidden]
+ @file = file
+ end
+
+ def hidden?
+ @hidden
+ end
+
+ def build_pdf_object(document)
+ obj = document.ref!(
+ Type: :Filespec,
+ F: file_name,
+ EF: { F: file },
+ UF: file_name
+ )
+
+ obj.data[:Desc] = description if description
+ obj
+ end
+
+ private
+
+ attr_reader :file, :description
+ end
+ end
+end