Class: Krikri::Activity

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
app/models/krikri/activity.rb

Overview

Activity wraps code execution with metadata about when it ran, which agents were responsible. It is designed to run a variety of different jobs, and its #run method is passed a block that performs the actual work. It records the start and end time of the job run, and provides the name of the agent to whomever needs it, but it does not care what kind of activity it is – harvest, enrichment, etc.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#agent ⇒ String

Returns a string representing the Krikri::SoftwareAgent responsible for the activity.

Returns:

  • (String) —

    a string representing the Krikri::SoftwareAgent responsible for the activity.



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# File 'app/models/krikri/activity.rb', line 22

validate :agent_must_be_a_software_agent

#end_time ⇒ DateTime

Returns a datestamp marking the activity’s competion.

Returns:

  • (DateTime) —

    a datestamp marking the activity’s competion



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# File 'app/models/krikri/activity.rb', line 22

validate :agent_must_be_a_software_agent

#opts ⇒ JSON

Returns the options to pass to the #agent class when running the activity.

Returns:

  • (JSON) —

    the options to pass to the #agent class when running the activity



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# File 'app/models/krikri/activity.rb', line 22

validate :agent_must_be_a_software_agent

#start_time ⇒ DateTime

Returns a datestamp marking the activity’s start.

Returns:

  • (DateTime) —

    a datestamp marking the activity’s start



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# File 'app/models/krikri/activity.rb', line 22

validate :agent_must_be_a_software_agent

Instance Method Details

#agent_instance ⇒ Agent

Instantiates and returns an instance of the Agent class with the values in opts.

Returns:

  • (Agent) —

    an instance of the class stored in Agent



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# File 'app/models/krikri/activity.rb', line 74

def agent_instance
  @agent_instance ||= agent.constantize.new(parsed_opts)
end

#agent_must_be_a_software_agent ⇒ Object 



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# File 'app/models/krikri/activity.rb', line 24

def agent_must_be_a_software_agent
  errors.add(:agent, 'does not represent a SoftwareAgent') unless
    agent.constantize < Krikri::SoftwareAgent
end

#ended? ⇒ Boolean

Indicates whether the activity has ended. Does not distinguish between successful and failed completion states.

Returns:

  • (Boolean) —

    ‘true` if the activity has been marked as ended, else `false`



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# File 'app/models/krikri/activity.rb', line 65

def ended?
  !self.end_time.nil?
end

#entities ⇒ Enumerator

Return an Enumerator of entities (e.g. aggregations or original records) that have been affected by this activity.

The kind of object that is returned depends on the EntityBehavior class that is associated with the SoftwareAgent that is represented by the Activity’s ‘agent’ field.

Returns:

  • (Enumerator) —

    Objects



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# File 'app/models/krikri/activity.rb', line 109

def entities
  agent_instance.entity_behavior.entities(self)
end

#entity_uris ⇒ Enumerator

Return an Enumerator of URI strings of entities (e.g. aggregations or original records) that pertain to this activity

Returns:

  • (Enumerator) —

    URI strings



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# File 'app/models/krikri/activity.rb', line 92

def entity_uris
  activity_uri = RDF::URI(rdf_subject)  # This activity's LDP URI
  query = Krikri::ProvenanceQueryClient.find_by_activity(activity_uri)
  query.each_solution.lazy.map do |s|
    s.record.to_s
  end
end

#parsed_opts ⇒ Object 



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# File 'app/models/krikri/activity.rb', line 78

def parsed_opts
  JSON.parse(opts, symbolize_names: true)
end

#rdf_subject ⇒ Object 



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# File 'app/models/krikri/activity.rb', line 82

def rdf_subject
  RDF::URI(Krikri::Settings['marmotta']['ldp']) /
    Krikri::Settings['prov']['activity'] / id.to_s
end

#run ⇒ Object

Runs the block, setting the start and end time of the run. The given block is passed an instance of the agent, and a URI representing this Activity.



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# File 'app/models/krikri/activity.rb', line 43

def run
  if block_given?
    update_attribute(:end_time, nil) if ended?
    set_start_time
    begin
      yield agent_instance, rdf_subject
    rescue => e
      Rails.logger.error("Error performing Activity: #{id}\n" \
                         "#{e.message}\n#{e.backtrace}")
      raise e
    ensure
      set_end_time
    end
  end
end

#set_end_time ⇒ Object 



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# File 'app/models/krikri/activity.rb', line 33

def set_end_time
  now = DateTime.now.utc
  fail 'Start time must exist and be before now to set an end time' unless
    self[:start_time] && (self[:start_time] <= now)
  update_attribute(:end_time, now)
end

#set_start_time ⇒ Object 



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# File 'app/models/krikri/activity.rb', line 29

def set_start_time
  update_attribute(:start_time, DateTime.now.utc)
end