Class: HL7::Message

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/ruby-hl7.rb

Overview

Ruby Object representation of an hl7 2.x message the message object is actually a “smart” collection of hl7 segments

Examples

Creating a new HL7 message

# create a message
msg = HL7::Message.new

# create a MSH segment for our new message
msh = HL7::Message::Segment::MSH.new
msh.recv_app = "ruby hl7"
msh.recv_facility = "my office"
msh.processing_id = rand(10000).to_s

msg << msh # add the MSH segment to the message

puts msg.to_s # readable version of the message

puts msg.to_hl7 # hl7 version of the message (as a string)

puts msg.to_mllp # mllp version of the message (as a string)

Parse an existing HL7 message

raw_input = open( "my_hl7_msg.txt" ).readlines
msg = HL7::Message.new( raw_input )

puts "message type: %s" % msg[:MSH].message_type

Defined Under Namespace

Classes: Segment

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(raw_msg = nil, &blk) ⇒ Message

setup a new hl7 message

raw_msg

is an optional object containing an hl7 message it can either be a string or an Enumerable object



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# File 'lib/ruby-hl7.rb', line 86

def initialize( raw_msg=nil, &blk )
  @segments = []
  @segments_by_name = {}
  @item_delim = "^"
  @element_delim = '|'
  @segment_delim = "\r"

  parse( raw_msg ) if raw_msg

  if block_given?
    blk.call self
  end
end

Instance Attribute Details

#element_delim ⇒ Object (readonly)

Returns the value of attribute element_delim.



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# File 'lib/ruby-hl7.rb', line 79

def element_delim
  @element_delim
end

#item_delim ⇒ Object (readonly)

Returns the value of attribute item_delim.



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# File 'lib/ruby-hl7.rb', line 80

def item_delim
  @item_delim
end

#segment_delim ⇒ Object (readonly)

Returns the value of attribute segment_delim.



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# File 'lib/ruby-hl7.rb', line 81

def segment_delim
  @segment_delim
end

Class Method Details

.parse(inobj) ⇒ Object

parse a String or Enumerable object into an HL7::Message if possible

  • returns a new HL7::Message if successful



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# File 'lib/ruby-hl7.rb', line 192

def parse( inobj )
  HL7::Message.new do |msg|
    msg.parse( inobj )
  end
end

.parse_batch(batch) ⇒ Object

:yields: message

Raises:



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# File 'lib/ruby-hl7.rb', line 162

def parse_batch(batch) # :yields: message
  raise HL7::ParseError, 'badly_formed_batch_message' unless
    batch.hl7_batch?

  # JRuby seems to change our literal \r characters in sample
  # messages (from here documents) into newlines.  We make a copy
  # here, reverting to carriage returns.  The input is unchanged.
  #
  # This does not occur when posts are received with CR
  # characters, only in sample messages from here documents.  The
  # expensive copy is only incurred when the batch message has a
  # newline character in it.
  batch = batch.gsub("\n", "\r") if batch.include?("\n")

  raise HL7::ParseError, 'empty_batch_message' unless
    match = /\rMSH/.match(batch)

  match.post_match.split(/\rMSH/).each_with_index do |_msg, index|
    if md = /\rBTS/.match(_msg)
      # TODO: Validate the message count in the BTS segment
      # should == index + 1
      _msg = md.pre_match
    end

    yield 'MSH' + _msg
  end
end

Instance Method Details

#<<(value) ⇒ Object

add a segment to the message

  • will force auto set_id sequencing for segments containing set_id’s



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# File 'lib/ruby-hl7.rb', line 149

def <<( value )
  unless ( value && value.kind_of?(HL7::Message::Segment) )
    raise HL7::Exception.new( "attempting to append something other than an HL7 Segment" )
  end

  value.segment_parent = self unless value.segment_parent
  (@segments ||= []) << value
  name = value.class.to_s.gsub("HL7::Message::Segment::", "").to_sym
  (@segments_by_name[ name ] ||= []) << value
  sequence_segments unless @parsing # let's auto-set the set-id as we go
end

#[](index) ⇒ Object

access a segment of the message

index

can be a Range, Fixnum or anything that responds to to_sym



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# File 'lib/ruby-hl7.rb', line 103

def []( index )
  ret = nil

  if index.kind_of?(Range) || index.kind_of?(Fixnum)
    ret = @segments[ index ]
  elsif (index.respond_to? :to_sym)
    ret = @segments_by_name[ index.to_sym ]
    ret = ret.first if ret && ret.length == 1
  end

  ret
end

#[]=(index, value) ⇒ Object

modify a segment of the message

index

can be a Range, Fixnum or anything that responds to to_sym

value

an HL7::Message::Segment object



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# File 'lib/ruby-hl7.rb', line 120

def []=( index, value )
  unless ( value && value.kind_of?(HL7::Message::Segment) )
    raise HL7::Exception.new( "attempting to assign something other than an HL7 Segment" )
  end

  if index.kind_of?(Range) || index.kind_of?(Fixnum)
    @segments[ index ] = value
  elsif index.respond_to?(:to_sym)
    (@segments_by_name[ index.to_sym ] ||= []) << value
  else
    raise HL7::Exception.new( "attempting to use an indice that is not a Range, Fixnum or to_sym providing object" )
  end

  value.segment_parent = self
end

#each ⇒ Object

yield each segment in the message



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# File 'lib/ruby-hl7.rb', line 213

def each # :yeilds: segment
  return unless @segments
  @segments.each { |s| yield s }
end

#index(value) ⇒ Object

return the index of the value if it exists, nil otherwise

value

is expected to be a string



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# File 'lib/ruby-hl7.rb', line 138

def index( value )
  return nil unless (value && value.respond_to?(:to_sym))

  segs = @segments_by_name[ value.to_sym ]
  return nil unless segs

  @segments.index( segs.to_a.first )
end

#length ⇒ Object

return the segment count



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# File 'lib/ruby-hl7.rb', line 219

def length
  0 unless @segments
  @segments.length
end

#parse(inobj) ⇒ Object

parse the provided String or Enumerable object into this message



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# File 'lib/ruby-hl7.rb', line 200

def parse( inobj )
  unless inobj.kind_of?(String) || inobj.respond_to?(:each)
    raise HL7::ParseError.new
  end

  if inobj.kind_of?(String)
      parse_string( inobj )
  elsif inobj.respond_to?(:each)
      parse_enumerable( inobj )
  end
end

#sequence_segments(base = nil) ⇒ Object

auto-set the set_id fields of any message segments that provide it and have more than one instance in the message



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# File 'lib/ruby-hl7.rb', line 242

def sequence_segments(base=nil)
  last = nil
  segs = @segments
  segs = base.children if base

  segs.each do |s|
    if s.kind_of?( last.class ) && s.respond_to?( :set_id )
      last.set_id = 1 unless last.set_id && last.set_id.to_i > 0
      s.set_id = last.set_id.to_i + 1
    end

    if s.respond_to?(:children)
      sequence_segments( s )
    end

    last = s
  end
end

#to_hl7 ⇒ Object

provide a HL7 spec version of the message



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# File 'lib/ruby-hl7.rb', line 230

def to_hl7
  @segments.collect { |s| s if s.to_s.length > 0 }.join( @segment_delim )
end

#to_mllp ⇒ Object

provide the HL7 spec version of the message wrapped in MLLP



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# File 'lib/ruby-hl7.rb', line 235

def to_mllp
  pre_mllp = to_hl7
  "\x0b" + pre_mllp + "\x1c\r"
end

#to_s ⇒ Object

provide a screen-readable version of the message



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# File 'lib/ruby-hl7.rb', line 225

def to_s
  @segments.collect { |s| s if s.to_s.length > 0 }.join( "\n" )
end