Module: SData::ActiveRecordExtensions::SdataUuidMixin::UuidClassMethods

Defined in:
lib/s_data/active_record_extensions/sdata_uuid_mixin.rb

Instance Method Summary collapse

Instance Method Details

#create_or_update_uuid_for(virtual_instance, uuid) ⇒ Object

TODO: handle case where virtual model depends on multiple models whose updated_at matter. This method can change the uuid of a given underlying BB model. It CANNOT set a uuid for the tuple [sd_class, bb_model_type] for a given bb_model_id if an instance of the tuple [sd_class, bb_model_type] with a different bb_model_id exists. To swap which bb_model_id of a [sd_class, bb_model_type] a uuid points to, use reassign_uuid!. Move the delete case to a separate method, and the controller should determine whether the request is deleting or not (does spec actually say you can delete a uuid by POST ing empty uuid to it? don’t you have to do a DELETE?). Because of unique index on [sd_class, bb_model, uuid] this has a race condition and can theoretically throw, but only if a linking engine is mistakenly sending multiple requests rapidly. The controller can just report a generic error.



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# File 'lib/s_data/active_record_extensions/sdata_uuid_mixin.rb', line 62

def create_or_update_uuid_for(virtual_instance, uuid)
  raise "Cannot create_or_update_uuid_for virtual_model (#{virtual_model.name}) with no fixed baze_class." if virtual_instance.class.baze_class.nil?
  raise "virtual_instance #{virtual_instance.inspect} has no baze" unless virtual_instance.baze
  return if uuid.blank?

  sd_uuid = SData::SdUuid.find_for_virtual_instance(virtual_instance)
  params = {:sd_class => virtual_instance.sdata_name,
                          :bb_model_type => virtual_instance.baze_class_name,
                          :bb_model_id => virtual_instance.baze.id,
                          :uuid => uuid}
  if sd_uuid
    sd_uuid.update_attributes!(params)
  else
    begin
      SData::SdUuid.create(params)
    rescue ::ActiveRecord::StatementInvalid
      raise Sage::BusinessLogic::Exception::IncompatibleDataException, "UUID already exists for another resource"
    end
  end
end

#enforce_uniqueness(sd_uuids, sd_class, baze_class_name) ⇒ Object 



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# File 'lib/s_data/active_record_extensions/sdata_uuid_mixin.rb', line 33

def enforce_uniqueness(sd_uuids, sd_class, baze_class_name)
  return nil if sd_uuids.nil? || sd_uuids.empty?
  if sd_uuids.count > 1
    RAILS_DEFAULT_LOGGER.fatal("SdUuid uniqueness violation for #{sd_class} - #{baze_class_name} - #{uuid}. Using first created")
    sd_uuids.sort_by!{|sid| sid.updated_at}
  end
  sd_uuids.first
end

#find_by_virtual_model_and_uuid(virtual_model, uuid) ⇒ Object 



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# File 'lib/s_data/active_record_extensions/sdata_uuid_mixin.rb', line 12

def find_by_virtual_model_and_uuid(virtual_model, uuid)
  sd_uuids = SData::SdUuid.find(:all, :conditions => {:sd_class => virtual_model.sdata_name, :bb_model_type => virtual_model.baze_class_name, :uuid => uuid})

  sd_uuid = enforce_uniqueness(sd_uuids, virtual_model.sdata_name, virtual_model.baze_class_name)
  
  raise "#{virtual_model.sdata_name} with UUID '#{uuid}' not found" unless sd_uuid
  virtual_model.build_for(sd_uuid.bb_model)    
end

#find_for_virtual_instance(virtual_instance, baze = nil) ⇒ Object

Handling multiple uuids: when linking and the resource already had a uuid on both sides, one provider wins and stores it’s uuid for the resource on the other provider (interop.sage.com/daisy/sdataSync/Link/525-DSY.html) At a later date sdata will provide an algorithm for uuid propagation; for the time being we assume the last stored is the correct one.



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# File 'lib/s_data/active_record_extensions/sdata_uuid_mixin.rb', line 25

def find_for_virtual_instance(virtual_instance, baze=nil)
  baze ||= virtual_instance.baze
  SData::SdUuid.first(:conditions => {:sd_class => virtual_instance.sdata_name, 
                                               :bb_model_type => baze.class.name.demodulize, 
                                               :bb_model_id => baze.id},
                                               :order => "updated_at DESC" )
end

#linked_bb_records(endpoint = nil) ⇒ Object

return all the bb_records which form the basis of this resource and which have been linked MJ TODO – check if there is a way to use the bb_model polymorphic assoc to autmatically create this query



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# File 'lib/s_data/active_record_extensions/sdata_uuid_mixin.rb', line 85

def linked_bb_records(endpoint=nil)
  klasses = baze_classes || [self]
  records = {}
  klasses.each do |klass|
    klassname = klass.name.demodulize
    tablename = klassname.tableize
    conditions = { :bb_model_type => klassname }
    # conditions[:endpoint] = endpoint  # we don't need this now
    records[klassname.to_sym] = klass.all(:joins => "INNER JOIN sd_uuids ON sd_uuids.bb_model_id = #{tablename}.id", 
        :conditions => {:sd_uuids => conditions})
  end
  records
end

#reassign_uuid!(uuid, virtual_model, new_id) ⇒ Object

This method is used to respond to a PUT to $linked(‘uuid’), to change what bb_model instance a uuid points to TODO this method makes no attempt to handle multiple baze_classes RADAR this method also has a RACE, but which should only happen when the provider/linking engine is doing something fubarred



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# File 'lib/s_data/active_record_extensions/sdata_uuid_mixin.rb', line 46

def reassign_uuid!(uuid, virtual_model, new_id)
  raise "Cannot edit uuid for virtual_model (#{virtual_model.name}) with no fixed baze_class." if virtual_model.baze_class.nil?
  sd_uuids = SData::SdUuid.find(:all, :conditions => {:sd_class => virtual_model.sdata_name, :bb_model_type => virtual_model.baze_class_name, :uuid => uuid})
  sd_uuid = enforce_uniqueness(sd_uuids, virtual_model.sdata_name, virtual_model.baze_class_name)
  sd_uuid.update_attributes!({:bb_model_id => new_id})
end