Module: TaliaUtil::Progressable

Included in:
TaliaCore::ActiveSource, TaliaCore::ActiveSourceParts::Rdf::RdfReader, TaliaCore::ActiveSourceParts::Xml::GenericReader
Defined in:
lib/talia_util/progressable.rb

Overview

Mix-in for a class that wishes to use decoupled progress meters. This creates an read/write accessor for a progressor, which is used to report progress to.

Inside the object #run_with_progress may be used to run a progress-reporting operation. If no progressor has been assigned, run_with_progress will still work as expected, providing a progressor object that will do nothing.

Example

class Foo

  include Progressable

  def long_thing
    run_with_progress("doing long thing", 100) { |prog| (1..100).each { prog.inc } }
  end
end

Foo.new.long_thing # Will do nothing
foo_real = Foo.new
foo_real.progressor = some_progressor
foo_real.long_thing # reports progress to some_progressor

How a progressor must look like

A progressor is simply required to provide a method called “run_with_progress(message, size)”, with the first parameter being the progress message and the second the overall count of operations. The method must take a block, and call that block with an object which responds to a method calle “inc”, which increases the current count/progress.

Example progressor

class DummyProgress
  def inc
    print '.'
  end
end

class SimpleProgressor
  def self.run_with_progress(message, size)
    puts message
    yield(DummyProgress.new)
    puts "Done"
  end
end

This will print a dot for each thing that is processed. See also the BarProgressor for another example

Instance Method Summary collapse

Instance Method Details

#progressor ⇒ Object

This is the object that will receive the progress messages



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# File 'lib/talia_util/progressable.rb', line 56

def progressor
  @progressor
end

#progressor=(progr) ⇒ Object

Set the progressor class. The progress class should simply respond to a #run_with_progress(message, size, &block) class

Raises:

  • (ArgumentError) 


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# File 'lib/talia_util/progressable.rb', line 62

def progressor=(progr)
  raise(ArgumentError, "Illegal progressor") unless((progr == nil) || progr.respond_to?(:run_with_progress))
  @progressor = progr
end

#run_with_progress(message, size, progr = nil, &block) ⇒ Object

Runs some block with a progress meter. The containing block will be passed an object on which #inc can be called to increase the meter.

If no progressor object is passed in manually, the one configured in the class is used



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# File 'lib/talia_util/progressable.rb', line 72

def run_with_progress(message, size, progr = nil, &block)
  if(progr_object = (progr || progressor))
    progr_object.run_with_progress(message, size, &block)
  else
    dummy_prog = Object.new
    class << dummy_prog
      def inc
      end
    end
    block.call(dummy_prog)
  end
end