Class: HexaPDF::Type::AcroForm::JavaScriptActions::SimplifiedFieldNotationParser

Inherits:
Object
  • Object
show all
Defined in:
lib/hexapdf/type/acro_form/java_script_actions.rb

Overview

Implements a parser for the simplified field notation used for calculating field values.

This notation is used if the predefined functions are too simple but the calculation can still be done by simple arithmetic.

Defined Under Namespace

Classes: ParseError

Instance Method Summary collapse

Constructor Details

#initialize(form, sfn_string) ⇒ SimplifiedFieldNotationParser

Creates a new instance for the given AcroForm form instance and simplified field notation string sfn_string.



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# File 'lib/hexapdf/type/acro_form/java_script_actions.rb', line 89

def initialize(form, sfn_string)
  @form = form
  @tokens = sfn_string.scan(/\p{Alpha}[^()*\/+-]*|\d+(?:[.,]\d*)?|[()*\/+-]/)
end

Instance Method Details

#parse(operations = :calculate) ⇒ Object

Parses the string holding the simplified field notation.

If operations is :calculate, the calculation is performed and the result returned. If operations is :generate, a JavaScript representation is generated and returned.

+nil+ is returned regardless of the +operations+ value if there was any problem.



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# File 'lib/hexapdf/type/acro_form/java_script_actions.rb', line 100

def parse(operations = :calculate)
  operations = (operations == :calculate ? CALCULATE_OPERATIONS : JS_GENERATE_OPERATIONS)
  result = expression(operations)
  @tokens.empty? ? result : nil
rescue ParseError
  nil
end