Module: AttrCsv::ClassMethods

Defined in:
lib/attr-csv.rb

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *arguments, &block) ⇒ Object 



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# File 'lib/attr-csv.rb', line 80

def method_missing(method, *arguments, &block)
  if method.to_s =~ /^((en|de)code)_(.+)$/ && attr_csved?($3)
    send($1, $3, *arguments)
  else
    super
  end
end

Instance Method Details

#attr_csv(*attributes) ⇒ Object 



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# File 'lib/attr-csv.rb', line 18

def attr_csv(*attributes)
  instance_methods_as_symbols = instance_methods.map { | mthd | mthd.to_sym }

  attributes.each do | attribute |
    # Construct the name to be used for the CSV version
    # of the attribute
    csv_attribute_name = [ attribute.to_s, CSV_ATTR_EXTENSION ].join.to_sym

    # Create the accessors for the csv attribute
    unless is_active_record_model?(self)
      attr_reader csv_attribute_name unless instance_methods_as_symbols.include?(csv_attribute_name)
      attr_writer csv_attribute_name unless instance_methods_as_symbols.include?("#{csv_attribute_name}=".to_sym)
    end

    # Now, define the array attribute reader
    define_method(attribute) do
      (instance_variable_get("@#{attribute}") || 
       instance_variable_set("@#{attribute}", 
                             decode(attribute, send(csv_attribute_name))))
    end

    # and the array attribute writer
    define_method("#{attribute}=") do | value |
      send("#{csv_attribute_name}=", encode(attribute, value))
      instance_variable_set("@#{attribute}", value)
    end

    define_method("#{attribute}?") do
      value = send(attribute)
      value.respond_to?(:empty?) ? !value.empty? : !!value
    end

    csved_attributes << attribute.to_sym

  end

end

#attr_csved?(attribute) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/attr-csv.rb', line 62

def attr_csved?(attribute)
  csved_attributes.include?(attribute.to_sym)
end

#csved_attributes ⇒ Object 



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# File 'lib/attr-csv.rb', line 66

def csved_attributes
  @csved_attributes ||= superclass.csved_attributes.dup
end

#decode(attribute, csv_value) ⇒ Object 



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# File 'lib/attr-csv.rb', line 70

def decode(attribute, csv_value)
  return [] if csv_value.nil? || csv_value.empty?
  CSV.parse(csv_value).first
end

#encode(attribute, array_value) ⇒ Object 



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# File 'lib/attr-csv.rb', line 75

def encode(attribute, array_value)
  return nil if array_value.nil? || array_value.empty?
  array_value.to_csv.chomp
end

#is_active_record_model?(clazz) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/attr-csv.rb', line 56

def is_active_record_model?(clazz)
  return false if clazz.nil?
  return true if clazz.to_s == 'ActiveRecord::Base'
  is_active_record_model?(clazz.superclass)
end