module CiteProc::Attributes::ClassMethods

# File lib/citeproc/attributes.rb, line 157
def attr_field(field, default = nil, predicate = false)
  method_id = field.to_s.downcase.gsub(/[-\s]+/, '_')

  unless instance_methods.include?(method_id)
    if default
      define_method(method_id) do
        read_attribute field
      end
    else
      define_method(method_id) do
        attributes[filter_key(field)] ||= default
      end
    end
  end

  writer_id = [method_id,'='].join
  unless instance_methods.include?(writer_id)
    define_method(writer_id) do |value|
      write_attribute field, value
    end
  end

  predicate_id = [method_id, '?'].join
  if predicate && !instance_methods.include?(predicate_id)
    define_method(predicate_id) do
      attribute?(field)
    end

    has_predicate = ['has_', predicate_id].join
    alias_method(has_predicate, predicate_id) unless instance_methods.include?(has_predicate)
  end
end

# File lib/citeproc/attributes.rb, line 151
def attr_fields(*arguments)
  arguments.flatten.each do |field|
    attr_field(*(field.is_a?(Hash) ? field.to_a.flatten : [field]))
  end
end

# File lib/citeproc/attributes.rb, line 144
def attr_predicates(*arguments)
  arguments.flatten.each do |field|
    field, default = *(field.is_a?(Hash) ? field.to_a.flatten : [field])
    attr_field(field, default, true)
  end
end

# File lib/citeproc/attributes.rb, line 134
def create(parameters)
  create!(parameters)
rescue
  nil
end

# File lib/citeproc/attributes.rb, line 140
def create!(parameters)
  new.merge(parameters)
end