Class: MARCSpec::Map

Inherits:
Object
  • Object
show all
Includes:
JLogger::Simple
Defined in:
lib/marcspec/map.rb

Overview

A Map is just a named lookup table. The access (via []) takes, in adition to a key, an optional default value to return (e.g., val = map[key, defaultIfNotFound])

We don't have the default be a part of the map because it might be used in several different contexts.

NOTE: THIS IS AN ABSTRACT SUPERCLASS. DO NOT INSTANTIATE IT DIRECTLY

Direct Known Subclasses

KVMap, MultiValueMap

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(mapname, map) ⇒ Map

Create a new map. The passed map is either a standard hash (KVMap) or a list of duples (for a MultiValueMap)

Parameters:

  • mapname (String) —

    The name of this map; can be used to find it later on.

  • map (Hash, Array) —

    Either a normal key-value hash (for a KV Map) or an array of duples (2-value arrays) for a MultiValueMap.



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# File 'lib/marcspec/map.rb', line 24

def initialize(mapname, map)
  @mapname = mapname
  @map = map
end

Instance Attribute Details

#map ⇒ Object

Returns the value of attribute map.



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# File 'lib/marcspec/map.rb', line 17

def map
  @map
end

#mapname ⇒ Object

Returns the value of attribute mapname.



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# File 'lib/marcspec/map.rb', line 17

def mapname
  @mapname
end

Class Method Details

.fromFile(filename) ⇒ Object

Load a map from a file, determining what kind it is along the way.

The file is valid ruby code; see the subclasses KVMap and MutlValueMap for examples.

Parameters:

  • filename (String) —

    The name of the map file to be eval'd

Returns:

  • MARC2Solr::Map An instance of a subclass of MARC2Solr::Map



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# File 'lib/marcspec/map.rb', line 36

def self.fromFile filename
  begin
    str = File.open(filename).read
  rescue Exception => e
     "Problem opening #{filename}: #{e}"
    raise e
  end
  
  begin 
    rawmap = eval(str)
  rescue Exception => e
    log.error "Problem evaluating (with 'eval') file #{filename}: #{e}"
    raise e
  end
  
  # Derive a name if there isn't one
  unless rawmap[:mapname]
    name = File.basename(filename)
    name.gsub! /\..*$/, '' # remove the extension
    rawmap[:mapname] = name
  end
  
  case rawmap[:maptype]
  when :kv
    return KVMap.new(rawmap[:mapname], rawmap[:map])
  when :multi
    return MultiValueMap.new(rawmap[:mapname], rawmap[:map])
  else
    log.error "Map file #{filename} doesn't seem to be either a KV map or a MuliValueMap according to :maptype (#{rawmap[:maptype]})"
    raise ArgumentError, "File #{filename} doesn't evaluate to a valid map"
  end
  
end

.fromHash(rawmap) ⇒ Object

Produce a map from the data structure produced by asPPString

Parameters:

  • rawmap (Hash) —

    A hash with two keys; :mapname and :map



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# File 'lib/marcspec/map.rb', line 83

def self.fromHash rawmap
  return self.new(rawmap[:mapname], rawmap[:map])
end

.fromPPString(str) ⇒ Object

Take the output of pretty_print and eval it to get rawmap; pass it tp fromHash to get the map object



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# File 'lib/marcspec/map.rb', line 89

def self.fromPPString str
  rawmap = eval(str)
  return self.fromHash rawmap
end

Instance Method Details

#==(other) ⇒ Object

Check for map equality



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# File 'lib/marcspec/map.rb', line 72

def == other
  return ((other.mapname == @mapname) and (other.map == @map))
end

#pretty_print(pp) ⇒ Object

Generic pretty_print; used mostly for translating from solrmarc



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# File 'lib/marcspec/map.rb', line 77

def pretty_print pp
  pp.pp eval(self.asPPString)
end