Class: MARC::FieldMap

Inherits:
Array
  • Object
show all
Defined in:
lib/marc/record.rb

Overview

The FieldMap is an Array of DataFields and Controlfields. It also contains a Hash representation of the fields for faster lookups (under certain conditions)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ FieldMap

Returns a new instance of FieldMap.



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# File 'lib/marc/record.rb', line 9

def initialize
  @tags = {}
  @clean = true
end

Instance Attribute Details

#clean ⇒ Object

Returns the value of attribute clean.



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# File 'lib/marc/record.rb', line 8

def clean
  @clean
end

#tags ⇒ Object (readonly)

Returns the value of attribute tags.



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# File 'lib/marc/record.rb', line 7

def tags
  @tags
end

Instance Method Details

#each_by_tag(tags) ⇒ Object

Returns an array of fields, in the order they appear, according to their tag. The tags argument can be a string (e.g. ‘245’), an array ([‘100’,‘700’,‘800’]) or a range ((‘600’..‘699’)).



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# File 'lib/marc/record.rb', line 34

def each_by_tag(tags)
  reindex unless @clean
  indices = @tags.values_at(*(@tags.keys & [*tags])).flatten.sort
  return [] if indices.empty?
  self.values_at(*indices).each do |tag|
    yield tag
  end
end

#reindex ⇒ Object

Rebuild the HashWithChecksumAttribute with the current values of the fields Array



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# File 'lib/marc/record.rb', line 16

def reindex
  @tags = {}
  self.each_with_index do |field, i|
    @tags[field.tag] ||= []
    @tags[field.tag] << i
  end
  @clean = true
end

#tag_list ⇒ Object

Returns an array of all of the tags that appear in the record (not in the order they appear, however).



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# File 'lib/marc/record.rb', line 26

def tag_list
  reindex unless @clean
  @tags.keys
end