Class: Ddr::Managers::DerivativesManager

Inherits:
Manager
  • Object
show all
Defined in:
lib/ddr/managers/derivatives_manager.rb

Defined Under Namespace

Classes: DerivativeJob

Constant Summary collapse

SCHEDULE_LATER = 
:later
SCHEDULE_NOW = 
:now
SCHEDULES = 
[ SCHEDULE_LATER, SCHEDULE_NOW ]
ACTION_DELETE = 
"delete"
ACTION_GENERATE = 
"generate"

Instance Attribute Summary

Attributes inherited from Manager

#object

Instance Method Summary collapse

Methods inherited from Manager

#initialize

Constructor Details

This class inherits a constructor from Ddr::Managers::Manager

Instance Method Details

#delete_derivative(derivative) ⇒ Object 



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# File 'lib/ddr/managers/derivatives_manager.rb', line 48

def delete_derivative(derivative)
  ActiveSupport::Notifications.instrument(Ddr::Notifications::UPDATE,
                                          pid: object.id,
                                          summary: "Delete derivative #{derivative.class.name}"
                                          ) do |payload|
    derivative.delete!(object)
  end
end

#delete_derivative!(derivative) ⇒ Object 



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# File 'lib/ddr/managers/derivatives_manager.rb', line 57

def delete_derivative!(derivative)
  File.unlink *object.datastreams[derivative.datastream].file_paths if
                                                object.datastreams[derivative.datastream].external?
  object.datastreams[derivative.datastream].delete
  object.save!
end

#generate_derivative(derivative) ⇒ Object 



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# File 'lib/ddr/managers/derivatives_manager.rb', line 39

def generate_derivative(derivative)
  ActiveSupport::Notifications.instrument(Ddr::Notifications::UPDATE,
                                          pid: object.id,
                                          summary: "Generate #{derivative.class.name} derivative"
                                          ) do |payload|
    derivative.generate!(object)
  end
end

#update_derivative(derivative) ⇒ Object 



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# File 'lib/ddr/managers/derivatives_manager.rb', line 27

def update_derivative(derivative)
  if derivative.class.generatable?(object)
    generate_derivative(derivative)
  else
    # Delete existing derivative (if there is one) if that type of derivative is no longer
    # applicable to the object
    if derivative.class.has_derivative?(object)
      delete_derivative(derivative)
    end
  end
end

#update_derivatives(schedule = SCHEDULE_LATER) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/ddr/managers/derivatives_manager.rb', line 14

def update_derivatives(schedule=SCHEDULE_LATER)
  raise ArgumentError, "Must be one of #{SCHEDULES}" unless SCHEDULES.include?(schedule)
  Ddr::Derivatives.update_derivatives.each do |derivative_to_update|
    derivative = Ddr::Derivatives::DERIVATIVES[derivative_to_update]
      # Need to update derivative if either (or both) of the following conditions are true:
      # - object already has this derivative (need to delete or replace it)
      # - the derivative can be generated for this object
    if derivative.class.has_derivative?(object) || derivative.class.generatable?(object)
      schedule == SCHEDULE_NOW ? update_derivative(derivative) : Resque.enqueue(DerivativeJob, object.id, derivative_to_update)
    end
  end
end