johnson_example.rb

#!/usr/bin/env ruby

require 'johnson'
require 'open-uri'
require 'yajl'

# Grab the source to the Javascript JSON implementation
json_js = open('http://www.json.org/json2.js').read
# Strip that silly alert at the top of the file
json_js.gsub!(/^(alert.*)$/, '/* \1 */')

# This is some Javascript you wanted to get something from

some_js = open('http://www.mol.fi/platser/scripts/scripts2.jsp?lang=sv').read

result = Johnson.evaluate(<<-EOF)
/* Include the JSON source code */
#{json_js}

/* Include the source code you wanted to get something from */
#{some_js}

/* Turn the things you wanted out into a string */
JSON.stringify([ LBval_3, LBtxt_3 ])
EOF

# Get the result back in ruby
ruby_result = Yajl::Parser.parse(result)

# Do something with it
puts ruby_result.inspect