Class: HashReader

Inherits:
Object
  • Object
show all
Includes:
LogUtils::Logging
Defined in:
lib/textutils/reader/hash_reader.rb

Instance Method Summary collapse

Constructor Details

#initialize(path) ⇒ HashReader

Returns a new instance of HashReader.



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# File 'lib/textutils/reader/hash_reader.rb', line 8

def initialize( path )
  @path = path

  ## nb: assume/enfore utf-8 encoding (with or without BOM - byte order mark)
  ## - see textutils/utils.rb
  
  text = File.read_utf8( @path )
 
  ### hack for syck yaml parser (e.g.ruby 1.9.2) (cannot handle !!null)
  ##   change it to !null to get plain nil
  ##   w/ both syck and psych/libyml

  text = text.gsub( '!!null', '!null' )
 
  ### hacks for yaml
  
  ### see yaml gotschas
  ##  - http://www.perlmonks.org/?node_id=738671
  ##  - 

  ## replace all tabs w/ two spaces and issue a warning
  ## nb: yaml does NOT support tabs see why here -> yaml.org/faq.html
  
  text = text.gsub( "\t" ) do |_|
    logger.warn "hash reader - found tab (\t) replacing w/ two spaces; yaml forbids tabs; see yaml.org/faq.html (path=#{path})"
    '  '  # replace w/ two spaces
  end

  ## quote implicit boolean types on,no,n,y

  ## nb: escape only if key e.g. no: or "free standing" value on its own line e.g.
  ##   no: no

  text = text.gsub( /^([ ]*)(ON|On|on|NO|No|no|N|n|Y|y)[ ]*:/ ) do |value|
    logger.warn "hash reader - found implicit bool (#{$1}#{$2}) for key; adding quotes to turn into string; see yaml.org/refcard.html (path=#{path})"
    # nb: preserve leading spaces for structure - might be significant
    "#{$1}'#{$2}':"  # add quotes to turn it into a string (not bool e.g. true|false)
  end

  ## nb: value must be freestanding (only allow optional eol comment)
  ##  do not escape if part of string sequence e.g.
  ##  key: nb,nn,no,se   => nb,nn,'no',se  -- avoid!!

  text = text.gsub( /:[ ]+(ON|On|on|NO|No|no|N|n|Y|y)[ ]*($| #.*$)/ ) do |value|
    logger.warn "hash reader - found implicit bool (#{$1}) for value; adding quotes to turn into string; see yaml.org/refcard.html (path=#{path})"
    ": '#{$1}'"  # add quotes to turn it into a string (not bool e.g. true|false)
  end

  
  @hash = YAML.load( text )
end

Instance Method Details

#each ⇒ Object

nb: returns all values as strings



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# File 'lib/textutils/reader/hash_reader.rb', line 64

def each
  @hash.each do |key_wild, value_wild|
    # normalize
    # - key n value as string (not symbols, bool? int? array?)
    # - remove leading and trailing whitespace
    key   = key_wild.to_s.strip
    value = value_wild.to_s.strip
    
    logger.debug "yaml key:#{key_wild.class.name} >>#{key}<<, value:#{value_wild.class.name} >>#{value}<<"
  
    yield( key, value )
  end
end

#each_typed ⇒ Object

todo: what name to use: each_object or each_typed ???

or use new TypedHashReader class or similar??



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# File 'lib/textutils/reader/hash_reader.rb', line 82

def each_typed
  @hash.each do |key_wild, value_wild|
    # normalize
    # - key n value as string (not symbols, bool? int? array?)
    # - remove leading and trailing whitespace
    key   = key_wild.to_s.strip
    
    if value_wild.is_a?( String )
      value = value_wild.strip
    else
      value = value_wild
    end
    
    logger.debug "yaml key:#{key_wild.class.name} >>#{key}<<, value:#{value_wild.class.name} >>#{value}<<"
  
    yield( key, value )
  end
end