Class: Dragonfly::TempObject

Inherits:
Object
  • Object
show all
Defined in:
lib/dragonfly/temp_object.rb

Overview

A TempObject is used for HOLDING DATA. It’s the thing that is passed between the datastore, the processor and the encoder, 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(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.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(obj, opts = {}) ⇒ TempObject

Instance Methods



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# File 'lib/dragonfly/temp_object.rb', line 43

def initialize(obj, opts={})
  opts ||= {} # in case it's nil
  initialize_from_object!(obj)
  validate_options!(opts)
  extract_attributes_from(opts)
end

Instance Attribute Details

#format ⇒ Object

Returns the value of attribute format



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# File 'lib/dragonfly/temp_object.rb', line 93

def format
  @format
end

#meta ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 97

def meta
  @meta ||= {}
end

#name ⇒ Object

Returns the value of attribute name



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# File 'lib/dragonfly/temp_object.rb', line 93

def name
  @name
end

Instance Method Details

#attributes ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 134

def attributes
  {
    :name => name,
    :meta => meta,
    :format => format
  }
end

#basename ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 101

def basename
  File.basename(name, '.*') if name
end

#data ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 50

def data
  @data ||= initialized_data || file{|f| f.read }
end

#each(&block) ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 109

def each(&block)
  to_io do |io|
    while part = io.read(block_size)
      yield part
    end
  end
end

#ext ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 105

def ext
  File.extname(name)[/\.(.*)/, 1] if name
end

#extract_attributes_from(hash) ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 142

def extract_attributes_from(hash)
  self.name   = hash.delete(:name)     unless hash[:name].blank?
  self.format = hash.delete(:format)   unless hash[:format].blank?
  self.meta.merge!(hash.delete(:meta)) unless hash[:meta].blank?
end

#file(&block) ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 69

def file(&block)
  f = tempfile.open
  tempfile.binmode
  if block_given?
    ret = yield f
    tempfile.close
  else
    ret = f
  end
  ret
end

#inspect ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 148

def inspect
  content_string = case initialized_with
  when :data
    data_string = size > 20 ? "#{initialized_data[0..20]}..." : initialized_data
    "data=#{data_string.inspect}"
  when :file then "file=#{initialized_file.inspect}"
  when :tempfile then "tempfile=#{initialized_tempfile.inspect}"
  end
  to_s.sub(/>$/, " #{content_string}, @meta=#{@meta.inspect}, @name=#{@name.inspect} >")
end

#path ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 81

def path
  tempfile.path
end

#size ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 85

def size
  if initialized_data
    initialized_data.bytesize
  else
    File.size(path)
  end
end

#tempfile ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 54

def tempfile
  @tempfile ||= begin
    case initialized_with
    when :tempfile
      @tempfile = initialized_tempfile
      @tempfile.close
    when :data
      @tempfile = new_tempfile(initialized_data)
    when :file
      @tempfile = copy_to_tempfile(initialized_file.path)
    end
    @tempfile
  end
end

#to_file(path) ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 117

def to_file(path)
  if initialized_data
    File.open(path, 'wb'){|f| f.write(initialized_data) }
  else
    FileUtils.cp(self.path, path)
  end
  File.new(path, 'rb')
end

#to_io(&block) ⇒ Object 



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# File 'lib/dragonfly/temp_object.rb', line 126

def to_io(&block)
  if initialized_data
    StringIO.open(initialized_data, 'rb', &block)
  else
    file(&block)
  end
end