Module: DICOM::ElementalParent

Included in:
Item, Sequence
Defined in:
lib/dicom/elemental_parent.rb

Overview

The ElementalParent mix-in module contains methods that are common among the two elemental parent classes: Item & Sequence

Instance Method Summary collapse

Instance Method Details

#add_item(item = nil, options = {}) ⇒ Object

Note:

Items are specified by index (starting at 0) instead of a tag string!

Adds a child item to a Sequence (or Item in some cases where pixel data is encapsulated).

If no existing Item is given, a new item will be created and added.

option options [Integer] :if specified, forces the item to be inserted at that specific index (Item number) option options [Boolean] :no_follow when true, the method does not update the parent attribute of the child that is added

  • options – A hash of parameters.

Examples:

Add an empty Item to a specific Sequence

dcm["3006,0020"].add_item

Add an existing Item at the 2nd item position/index in the specific Sequence

dcm["3006,0020"].add_item(my_item, :index => 1)

Parameters:

  • item (Item) (defaults to: nil) —

    the Item instance to be added

  • options (Hash) (defaults to: {}) —

    the options used for adding the item



24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
 
# File 'lib/dicom/elemental_parent.rb', line 24

def add_item(item=nil, options={})
  if item
    if item.is_a?(Item)
      if index = options[:index]
        # This Item will take a specific index, and all existing Items with index higher or equal to this number will have their index increased by one.
        # Check if index is valid (must be an existing index):
        if index >= 0
          # If the index value is larger than the max index present, we dont need to modify the existing items.
          if index < @tags.length
            @tags = @tags.create_key_gap_at(index)
          else
            # Set the index value one higher than the already existing max value:
            index = @tags.length
          end
          #,Add the new Item and set its index:
          @tags[index] = item
          item.index = index
        else
          raise ArgumentError, "The specified index (#{index}) is out of range (must be a positive integer)."
        end
      else
        # Add the existing Item to this Sequence:
        index = @tags.length
        @tags[index] = item
        # Let the Item know what index key it's got in it's parent's Hash:
        item.index = index
      end
      # Set ourself as this item's new parent:
      item.set_parent(self) unless options[:no_follow]
    else
      raise ArgumentError, "Expected Item, got #{item.class}"
    end
  else
    # Create an empty item with self as parent:
    item = Item.new(:parent => self)
  end
end