Module: HL7::Message::SegmentFields::ClassMethods

Defined in:
lib/segment_fields.rb

Instance Method Summary collapse

Instance Method Details

#add_field(name, options = {}, &blk) ⇒ Object

define a field alias

  • name is the alias itself (required)

  • options is a hash of parameters

    • :id is the field number to reference (optional, auto-increments from 1

      by default)

    • :blk is a validation proc (optional, overrides the second argument)

  • blk is an optional validation/convertion proc which MUST take a parameter and always return a value for the field (it will be

    used on read/write calls)



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# File 'lib/segment_fields.rb', line 25

def add_field(name, options = {}, &blk)
  options = { :idx => -1, :blk => blk }.merge!(options)
  name ||= :id
  namesym = name.to_sym
  @field_cnt ||= 1
  if options[:idx] == -1
    options[:idx] = @field_cnt # provide default auto-incrementing
  end
  @field_cnt = options[:idx].to_i + 1

  singleton.module_eval do
    @fields ||= {}
    @fields[namesym] = options
  end

  class_eval <<-END, __FILE__, __LINE__ + 1
    def #{name}(val=nil)
      unless val
        read_field( :#{namesym} )
      else
        write_field( :#{namesym}, val )
        val # this matches existing n= method functionality
      end
    end

    def #{name}=(value)
      write_field( :#{namesym}, value )
    end
  END
end

#alias_field(new_field_name, old_field_name) ⇒ Object 



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# File 'lib/segment_fields.rb', line 62

def alias_field(new_field_name, old_field_name)
  class_eval <<-END, __FILE__, __LINE__ + 1
    def #{new_field_name}(val=nil)
      raise HL7::InvalidDataError.new unless self.class.fields[:#{old_field_name}]
      unless val
        read_field( :#{old_field_name} )
      else
        write_field( :#{old_field_name}, val )
        val # this matches existing n= method functionality
      end
    end

    def #{new_field_name}=(value)
      write_field( :#{old_field_name}, value )
    end
  END
end

#fields ⇒ Object

:nodoc:



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# File 'lib/segment_fields.rb', line 56

def fields # :nodoc:
  singleton.module_eval do
    (@fields ||= [])
  end
end