Class: MARC::AlephSequential::ASLineGroup

Inherits:
Object
  • Object
show all
Includes:
Log
Defined in:
lib/marc_alephsequential/asline_group.rb

Overview

A group of ASLine objects with logic to correctly turn them into a MARC::Record object

See Also:

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Log

log, #log, log=

Constructor Details

#initialize ⇒ ASLineGroup

Returns a new instance of ASLineGroup.



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# File 'lib/marc_alephsequential/asline_group.rb', line 26

def initialize
  @aslines = []
  @leader = nil
end

Instance Attribute Details

#aslines ⇒ Array<MARC::Field>

Returns Internal list of MARC field object.

Returns:

  • (Array<MARC::Field>) —

    Internal list of MARC field object



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# File 'lib/marc_alephsequential/asline_group.rb', line 18

def aslines
  @aslines
end

#leader ⇒ Object (readonly)

Returns the value of attribute leader.



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# File 'lib/marc_alephsequential/asline_group.rb', line 22

def leader
  @leader
end

Instance Method Details

#add(asline) ⇒ Undefined

Add an ASLine object, turning it into the appropriate type of field as we go An ASLine object with type :invalid_id will be treated as a string and appended to the previous field (to deal with not-uncommon spurious newlines in data fields) field to concatentate it to.

Returns:

  • (Undefined) —

    side effect only

Raises:

  • MARC::AlephSequential::Error when there's an invalid ID and there's no previous



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# File 'lib/marc_alephsequential/asline_group.rb', line 50

def add(asline)
  case asline.type
  when :leader
    if leader
      log.warn("#{asline.line_number} #{asline.id} Set leader more than once; last one wins")
    end
    @leader = asline.value
  when :invalid_id
    lastfield = @aslines.pop
    unless lastfield
      raise MARC::AlephSequential::Error.new('unknown', asline.line_number),  
            "#{asline.line_number} has invalid id and no preivous line to concat it to (file starts bad?)"
            nil
    end
    log.info "#{asline.line_number} #{lastfield.id} / #{lastfield.tag} Concatenating line #{asline.line_number} to previous line"
    @aslines.push ASLine.new(lastfield.rawstr +  asline.rawstr, lastfield.line_number)
  else
    @aslines.push asline
  end
end

#add_string(asline_string, line_number) ⇒ Object

Add an asline as a raw string



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# File 'lib/marc_alephsequential/asline_group.rb', line 73

def add_string(asline_string, line_number)
  self.add(ASLine.new(asline_string, line_number))
end

#as_record ⇒ MARC::Record Also known as: to_record

Turn this object into a MARC::Record

Returns:

  • (MARC::Record)

Raises:

  • MARC::AlephSequential::Error if this object is empty

  • MARC::AlephSequential::Error if there's no leader



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# File 'lib/marc_alephsequential/asline_group.rb', line 81

def as_record
  if empty?
    raise MARC::AlephSequential::Error.new('unknown', 'unknown'), "Can't turn an empty group into a record", nil
  end
  
  unless leader
    raise MARC::AlephSequential::Error.new(@aslines[0].id, @aslines[0].line_number),
          "Record #{@aslines[0].id} (near line #{ @aslines[0].line_number}) has no leader; can't turn into a record",
          nil
  end
  r = MARC::Record.new
  r.leader = leader
  aslines.map {|f| r << f.to_field}
  return r
end

#empty? ⇒ Boolean

Is this group empty?

Returns:

  • (Boolean) 


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# File 'lib/marc_alephsequential/asline_group.rb', line 38

def empty?
  aslines.empty?
end

#size ⇒ Object

Number of aslines already added

Returns:

  • Integer



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# File 'lib/marc_alephsequential/asline_group.rb', line 33

def size
  aslines.size
end