Class: OpenHAB::Console::JLine

Inherits:
Object
  • Object
show all
Defined in:
lib/openhab/console/jline.rb

Overview

A basic JRuby REPL for openHAB Karaf console

To use this, set the jrubyscripting add-on ‘console` configuration to `jline`

Constant Summary collapse

LineReader =

Create constants instead of java_import to avoid polluting the global namespace

org.jline.reader.LineReader
Bracket = 
org.jline.reader.impl.DefaultParser::Bracket
BOLD = 
"\e[1m"
RESET = 
"\e[0m"
RED = 
"\e[31m"
GREEN = 
"\e[32m"
YELLOW = 
"\e[33m"
BLUE = 
"\e[34m"
CYAN = 
"\e[36m"
ERROR = 
RED
STRING = 
BOLD + YELLOW
NUMBER = 
BOLD + BLUE
OBJECT = 
BOLD + GREEN
SIMPLE_CLASS = 
BOLD + CYAN
PROMPT = 
"#{BOLD}JRuby> #{RESET}".freeze

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ JLine

Returns a new instance of JLine.



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# File 'lib/openhab/console/jline.rb', line 59

def initialize
  parser = org.jline.reader.impl.DefaultParser.new
              .eof_on_unclosed_bracket(Bracket::CURLY, Bracket::ROUND, Bracket::SQUARE)
              .eof_on_unclosed_quote(true)
              .eof_on_escaped_new_line(true)

  completer =
    org.jline.reader.Completer.impl do |_method_name, _reader, _line, candidates|
      sources = TOPLEVEL_BINDING.local_variables + Object.constants
      sources += DSL.items.map(&:name) + DSL.methods(false) if defined?(DSL)

      candidates.add_all(sources.map { |c| org.jline.reader.Candidate.new(c.to_s) })
    end

  @reader = org.jline.reader.LineReaderBuilder.builder
               .terminal($terminal)
               .app_name("jrubyscripting")
               .parser(parser)
               .completer(completer)
               .variable(LineReader::SECONDARY_PROMPT_PATTERN, "%M%P > ")
               .variable(LineReader::INDENTATION, 2)
               .build
end

Class Method Details

.start ⇒ Object 



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# File 'lib/openhab/console/jline.rb', line 33

def start
  puts "Welcome to JRuby REPL. Press Ctrl+D to exit, Alt+Enter (or Esc,Enter) to insert a new line."

  console = new

  loop do
    begin
      input = console.read_line
      next if input.strip.empty?
    rescue org.jline.reader.UserInterruptException # Ctrl+C is pressed
      next
    rescue org.jline.reader.EndOfFileException # Ctrl+D is pressed
      break
    end

    begin
      # Use TOPLEVEL_BINDING to isolate and keep the local variables between loops
      result = TOPLEVEL_BINDING.eval(input)
      console.print_result(result)
    rescue Exception => e
      console.print_error(e)
    end
  end
end

Instance Method Details



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# File 'lib/openhab/console/jline.rb', line 97

def print_error(error)
  puts ERROR + "Error: #{error.message}" + RESET
end

#print_result(result) ⇒ Object 



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# File 'lib/openhab/console/jline.rb', line 87

def print_result(result)
  puts "=> " + # rubocop:disable Style/StringConcatenation
       case result
       when nil, true, false then SIMPLE_CLASS + result.inspect + RESET
       when String then %("#{STRING}#{result.dump[1..-2]}#{RESET}")
       when Numeric, Array, Hash then NUMBER + result.to_s + RESET
       else OBJECT + result.inspect + RESET
       end
end

#read_line ⇒ Object 



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# File 'lib/openhab/console/jline.rb', line 83

def read_line
  @reader.read_line(PROMPT)
end