Class: ETL::Control::YamlDestination

Inherits:
Destination show all
Defined in:
lib/etl/control/destination/yaml_destination.rb

Instance Attribute Summary collapse

Attributes inherited from Destination

#append_rows, #buffer_size, #condition, #configuration, #control, #mapping, #unique

Instance Method Summary collapse

Methods inherited from Destination

class_for_name, #current_row, #errors, #write

Constructor Details

#initialize(control, configuration, mapping = {}) ⇒ YamlDestination

Initialize the object.

  • control: The Control object

  • configuration: The configuration map

  • mapping: The output mapping

Configuration options:

  • <tt>:file<tt>: The file to write to (REQUIRED)

  • :append: Set to true to append to the file (default is to overwrite)

  • :only

  • :except

Raises:



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# File 'lib/etl/control/destination/yaml_destination.rb', line 17

def initialize(control, configuration, mapping={})
  super
  @file = File.join(File.dirname(control.file), configuration[:file])
  @append = configuration[:append] ||= false
  @only = configuration[:only]
  @except = configuration[:except]
  raise ControlError, "the :only and :except options must be used seperately, do not specify both" if @only && @except
end

Instance Attribute Details

#append ⇒ Object (readonly)

Returns the value of attribute append.



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# File 'lib/etl/control/destination/yaml_destination.rb', line 6

def append
  @append
end

#except ⇒ Object (readonly)

Returns the value of attribute except.



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# File 'lib/etl/control/destination/yaml_destination.rb', line 6

def except
  @except
end

#file ⇒ Object (readonly)

Returns the value of attribute file.



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# File 'lib/etl/control/destination/yaml_destination.rb', line 6

def file
  @file
end

#only ⇒ Object (readonly)

Returns the value of attribute only.



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# File 'lib/etl/control/destination/yaml_destination.rb', line 6

def only
  @only
end

Instance Method Details

#close ⇒ Object

Close the destination. This will flush the buffer and close the underlying stream or connection.



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# File 'lib/etl/control/destination/yaml_destination.rb', line 27

def close
  flush
  f.close
end

#flush ⇒ Object

Flush the destination buffer



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# File 'lib/etl/control/destination/yaml_destination.rb', line 33

def flush
  #puts "Flushing buffer (#{file}) with #{buffer.length} rows"
  buffer.flatten.each do |row|
    # check to see if this row's compound key constraint already exists
    # note that the compound key constraint may not utilize virtual fields
    next unless row_allowed?(row)
    # add any virtual fields
    add_virtuals!(row)

    yaml = {}
    row.each do |key, value|
      next if only && !only.include?(key)
      next if except && except.include?(key)

      case value
      when Date, Time, DateTime
        value = value.to_s(:db)
      end

      yaml[key] = value
    end
   
    # write the values
    YAML.dump(yaml, f)
  end
  f.flush
  buffer.clear
end