Class: Sequence::SequencePhrase

Inherits:
Object
  • Object
show all
Defined in:
lib/lucid/sequence/sequence_phrase.rb

Constant Summary collapse

ParameterConstant = 
{ 'quotes' => '"""'}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(phrase, sequence, data) ⇒ SequencePhrase

Returns a new instance of SequencePhrase.



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 14

def initialize(phrase, sequence, data)
  @key = self.class.sequence_key(phrase, data, :define)
  #puts "*** [Sequence Step] - Key: #{@key}"

  @phrase_params = scan_parameters(phrase, :define)
  #puts "*** [Sequence Step] - Phrase Params: #{@phrase_params}"
  
  transformed_steps = preprocess(sequence)
  #puts "*** [Sequence Step] - Steps: \n#{transformed_steps}"

  @template = SequenceTemplate::Engine.new(transformed_steps)
  #puts "\n*** [Sequence Step] - Template: #{@template.inspect}\n"

  phrase_variables = template.variables
  #puts "\n*** [Sequence Step] - Phrase Variables: #{phrase_variables}"
  
  @values = validate_phrase_values(@phrase_params, phrase_variables)
  @values.concat(phrase_variables)
  #puts "*** [Sequence Step] - Values: #{@values}"
  
  @values.uniq!
end

Instance Attribute Details

#key ⇒ Object (readonly)

Returns the value of attribute key.



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 7

def key
  @key
end

#phrase_params ⇒ Object (readonly)

Returns the value of attribute phrase_params.



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 10

def phrase_params
  @phrase_params
end

#template ⇒ Object (readonly)

Returns the value of attribute template.



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 9

def template
  @template
end

#values ⇒ Object (readonly)

Returns the value of attribute values.



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 8

def values
  @values
end

Class Method Details

.sequence_key(phrase, data, mode) ⇒ Object 



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 37

def self.sequence_key(phrase, data, mode)
  new_phrase = phrase.strip

  # These lines replace every series of whitespace with an underscore.
  # For that to work, I have to make sure there are no existing
  # underscore characters in the first place so any pre-existing
  # underscores get removed first.
  new_phrase.gsub!(/_/, '')
  new_phrase.gsub!(/\s+/, '_')

  pattern = case mode
              when :define
                /<(?:[^\\<>]|\\.)*>/
              when :invoke
                /"([^\\"]|\\.)*"/
            end

  # Here 'patterned' means that for a given phrase, any bit of text
  # between quotes or chevrons is replaced by the letter X.
  patterned = new_phrase.gsub(pattern, 'X')

  key = patterned + (data ? '_T' : '')
  
  return key
end

Instance Method Details

#data_table_required? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/lucid/sequence/sequence_phrase.rb', line 117

def data_table_required?
  return key =~ /_T$/
end

#expand(phrase, data) ⇒ Object 



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 121

def expand(phrase, data)
  params = validate_params(phrase, data)
  params = ParameterConstant.merge(params)
  return template.output(nil, params)
end

#preprocess(sequence) ⇒ Object 



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 83

def preprocess(sequence)
  # Split text into individual lines and make sure to remove any lines
  # with hash style comments.
  lines = sequence.split(/\r\n?|\n/)
  processed = lines.reject { |line| line =~ /\s*#/ }

  return processed.join("\n")
end

#scan_parameters(phrase, mode) ⇒ Object

“Scanning parameters” means that a phrase will be scanned to find any text between chevrons or double quotes. These will be placed into an array.



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 66

def scan_parameters(phrase, mode)
  pattern = case mode
              when :define
                /<((?:[^\\<>]|\\.)*)>/
              when :invoke
                /"((?:[^\\"]|\\.)*)"/
            end

  result = phrase.scan(pattern)
  params = result.flatten.compact
  
  # Any escaped double quotes need to be replaced by a double quote.
  params.map! { |item| item.sub(/\\"/, '"') } if mode == :invoke
  
  return params
end

#validate_params(phrase, data) ⇒ Object 



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 127

def validate_params(phrase, data)
  sequence_parameters = {}
  
  quoted_values = scan_parameters(phrase, :invoke)
  quoted_values.each_with_index do |val, index|
    sequence_parameters[phrase_params[index]] = val
  end

  unless data.nil?
    data.each do |row|
      (key, value) = validate_row(row, sequence_parameters)
      if sequence_parameters.include? key
        if sequence_parameters[key].kind_of?(Array)
          sequence_parameters[key] << value
        else
          sequence_parameters[key] = [sequence_parameters[key], value]
        end
      else
        sequence_parameters[key] = value
      end
    end
  end

  return sequence_parameters
end

#validate_phrase_values(params, phrase_variables) ⇒ Object

The goal of this method is to check for various inconsistencies that can occur between parameter names in the sequence phrase and those in the actual steps.



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 95

def validate_phrase_values(params, phrase_variables)
  # This covers the case when phrase names a parameter that never
  # occurs in any of the steps.
  params.each do |param|
    unless phrase_variables.include? param
      raise UselessPhraseParameter.new(param)
    end
  end

  # This covers the case when a step has a parameter that never appears
  # in the sequence phrase and when data table is not being used.
  unless data_table_required?
    phrase_variables.each do |variable|
      unless params.include?(variable) || ParameterConstant.include?(variable)
        raise UnreachableStepParameter.new(variable)
      end
    end  
  end
  
  return phrase_params.dup
end

#validate_row(row, params) ⇒ Object

Raises:



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# File 'lib/lucid/sequence/sequence_phrase.rb', line 153

def validate_row(row, params)
  (key, value) = row

  raise UnknownParameterError.new(key) unless values.include? key

  if (phrase_params.include? key) && (params[key] != value)
    raise AmbiguousParameterValue.new(key, params[key], value)
  end

  return row
end