class Dragonfly::TempObject

A TempObject is used for HOLDING DATA. It's the thing that is passed between the datastore and the processor, and is useful for separating how the data was created and how it is later accessed.

You can initialize it various ways:

temp_object = Dragonfly::TempObject.new('this is the content')           # with a String
temp_object = Dragonfly::TempObject.new(Pathname.new('path/to/content')) # with a Pathname
temp_object = Dragonfly::TempObject.new(File.new('path/to/content'))     # with a File
temp_object = Dragonfly::TempObject.new(some_tempfile)                   # with a Tempfile
temp_object = Dragonfly::TempObject.new(some_other_temp_object)          # with another TempObject

However, no matter how it was initialized, you can always access the data a number of ways:

temp_object.data      # returns a data string
temp_object.file      # returns a file object holding the data
temp_object.path      # returns a path for the file

The data/file are created lazily, something which you may wish to take advantage of.

For example, if a TempObject is initialized with a file, and temp_object.data is never called, then the data string will never be loaded into memory.

Conversely, if the TempObject is initialized with a data string, and neither temp_object.file nor temp_object.path are ever called, then the filesystem will never be hit.

Attributes

name[R]

Public Class Methods

new(obj, name=nil) click to toggle source

Instance Methods

# File lib/dragonfly/temp_object.rb, line 42
def initialize(obj, name=nil)
  if obj.is_a? TempObject
    @data = obj.get_data
    @tempfile = obj.get_tempfile
    @pathname = obj.get_pathname
  elsif obj.is_a? String
    @data = obj
  elsif obj.is_a? Tempfile
    @tempfile = obj
  elsif obj.is_a? File
    @pathname = Pathname.new(obj.path)
  elsif obj.is_a? Pathname
    @pathname = obj
  elsif obj.respond_to?(:tempfile)
    @tempfile = obj.tempfile
  elsif obj.respond_to?(:path) # e.g. Rack::Test::UploadedFile
    @pathname = Pathname.new(obj.path)
  else
    raise ArgumentError, "#{self.class.name} must be initialized with a String, a Pathname, a File, a Tempfile, another TempObject, something that responds to .tempfile, or something that responds to .path - you gave #{obj.inspect}"
  end

  @tempfile.close if @tempfile

  # Name
  @name = if name
    name
  elsif obj.respond_to?(:original_filename)
    obj.original_filename
  elsif @pathname
    @pathname.basename.to_s
  end
end

Public Instance Methods

close() click to toggle source
# File lib/dragonfly/temp_object.rb, line 140
def close
  @tempfile.close! if @tempfile
  @data = nil
  @closed = true
end
closed?() click to toggle source
# File lib/dragonfly/temp_object.rb, line 146
def closed?
  !!@closed
end
data() click to toggle source
# File lib/dragonfly/temp_object.rb, line 83
def data
  raise Closed, "can't read data as TempObject has been closed" if closed?
  @data ||= file{|f| f.read }
end
each() { |part| ... } click to toggle source
# File lib/dragonfly/temp_object.rb, line 110
def each(&block)
  to_io do |io|
    while part = io.read(block_size)
      yield part
    end
  end
end
ext() click to toggle source
# File lib/dragonfly/temp_object.rb, line 77
def ext
  if n = name
    n.split('.').last
  end
end
file() { |f| ... } click to toggle source
# File lib/dragonfly/temp_object.rb, line 88
def file(&block)
  f = tempfile.open
  tempfile.binmode
  if block_given?
    ret = yield f
    tempfile.close unless tempfile.closed?
  else
    ret = f
  end
  ret
end
inspect() click to toggle source
# File lib/dragonfly/temp_object.rb, line 150
def inspect
  content_string = case
  when @data
    data_string = size > 20 ? "#{@data[0..20]}..." : @data
    "data=#{data_string.inspect}"
  when @pathname then "pathname=#{@pathname.inspect}"
  when @tempfile then "tempfile=#{@tempfile.inspect}"
  end
  "<#{self.class.name} #{content_string} >"
end
path() click to toggle source
# File lib/dragonfly/temp_object.rb, line 100
def path
  @pathname ? @pathname.expand_path.to_s : tempfile.path
end
size() click to toggle source
# File lib/dragonfly/temp_object.rb, line 104
def size
  @tempfile && @tempfile.size ||
  @data && @data.bytesize ||
  File.size(path)
end
to_file(path, opts={}) click to toggle source
# File lib/dragonfly/temp_object.rb, line 118
def to_file(path, opts={})
  mode = opts[:mode] || 0644
  prepare_path(path) unless opts[:mkdirs] == false
  if @data
    File.open(path, 'wb', mode){|f| f.write(@data) }
  else
    FileUtils.cp(self.path, path)
    File.chmod(mode, path)
  end
  File.new(path, 'rb')
end
to_io(&block) click to toggle source
# File lib/dragonfly/temp_object.rb, line 136
def to_io(&block)
  @data ? StringIO.open(@data, 'rb', &block) : file(&block)
end
to_tempfile() click to toggle source
# File lib/dragonfly/temp_object.rb, line 130
def to_tempfile
  tempfile = copy_to_tempfile(path)
  tempfile.open
  tempfile
end

Protected Instance Methods

get_data() click to toggle source

We don't use normal accessors here because data etc. do more than just return the instance var

# File lib/dragonfly/temp_object.rb, line 164
def get_data
  @data
end
get_pathname() click to toggle source
# File lib/dragonfly/temp_object.rb, line 168
def get_pathname
  @pathname
end
get_tempfile() click to toggle source
# File lib/dragonfly/temp_object.rb, line 172
def get_tempfile
  @tempfile
end

Private Instance Methods

block_size() click to toggle source
# File lib/dragonfly/temp_object.rb, line 191
def block_size
  8192
end
copy_to_tempfile(path) click to toggle source
# File lib/dragonfly/temp_object.rb, line 195
def copy_to_tempfile(path)
  tempfile = Utils.new_tempfile(ext)
  FileUtils.cp path, tempfile.path
  tempfile
end
prepare_path(path) click to toggle source
# File lib/dragonfly/temp_object.rb, line 201
def prepare_path(path)
  dir = File.dirname(path)
  FileUtils.mkdir_p(dir) unless File.exist?(dir)
end
tempfile() click to toggle source
# File lib/dragonfly/temp_object.rb, line 178
def tempfile
  raise Closed, "can't read from tempfile as TempObject has been closed" if closed?
  @tempfile ||= begin
    case
    when @data
      @tempfile = Utils.new_tempfile(ext, @data)
    when @pathname
      @tempfile = copy_to_tempfile(@pathname.expand_path)
    end
    @tempfile
  end
end