Class: ImageOptim::Handler

Inherits:
Object
  • Object
show all
Defined in:
lib/image_optim/handler.rb

Overview

Handles processing of original to result using upto two temp files

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(original) ⇒ Handler

original must respond to temp_path



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# File 'lib/image_optim/handler.rb', line 10

def initialize(original)
  unless original.respond_to?(:temp_path)
    fail ArgumentError, 'original should respond to temp_path'
  end

  @original = original
  @result = nil
end

Instance Attribute Details

#result ⇒ Object (readonly)

Holds latest successful result



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# File 'lib/image_optim/handler.rb', line 7

def result
  @result
end

Class Method Details

.for(original) ⇒ Object

with no associated block, works as new. Otherwise creates instance and passes it to block, runs cleanup and returns result of handler



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# File 'lib/image_optim/handler.rb', line 21

def self.for(original)
  handler = new(original)
  if block_given?
    begin
      yield handler
      handler.result
    ensure
      handler.cleanup
    end
  else
    handler
  end
end

Instance Method Details

#cleanup ⇒ Object

Remove extra temp files



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# File 'lib/image_optim/handler.rb', line 51

def cleanup
  return unless @dst
  @dst.unlink
  @dst = nil
end

#process ⇒ Object

Yields two paths, one to latest successful result or original, second to temp path



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# File 'lib/image_optim/handler.rb', line 37

def process
  @src ||= @original
  @dst ||= @original.temp_path

  return unless yield @src, @dst
  @result = @dst
  if @src == @original
    @src, @dst = @dst, nil
  else
    @src, @dst = @dst, @src
  end
end