[Truffle] Demo of interop with JS.

chrisseaton · chrisseaton · commit e64c83f70a73 · 2016-06-22T14:03:07.000+01:00
diff --git a/samples/truffle/interop/weather/README.md b/samples/truffle/interop/weather/README.md
@@ -0,0 +1,10 @@
+```
+$ git clone https://github.com/lucasocon/openweather.git
+RUBYOPT='-I samples/truffle/interop/weather/openweather/lib -I samples/truffle/interop/weather' graalvm/bin/js samples/truffle/interop/weather/weather.js
+```
+
+The demo hangs after printing the temperature, as some Ruby service threads
+get stuck and aren't shutting down properly.
+
+The Ruby `temperature_in_city` method has a `this` parameter which it wouldn't
+normally have, because JS passes `this` as the first argument.
diff --git a/samples/truffle/interop/weather/weather.js b/samples/truffle/interop/weather/weather.js
@@ -0,0 +1,5 @@
+Interop.eval('application/x-ruby', 'require "weather"');
+
+temperature_in_city = Interop.import('temperature_in_city')
+
+console.log('Temperature in New York now: ' + temperature_in_city('New York') + '℃');
diff --git a/samples/truffle/interop/weather/weather.rb b/samples/truffle/interop/weather/weather.rb
@@ -0,0 +1,15 @@
+require 'openweather2'
+
+Openweather2.configure do |config|
+  # This is the endpoint and API key from the tests in the Openweather2 gem
+  config.endpoint = 'http://api.openweathermap.org/data/2.5/weather'
+  config.apikey = 'dd7073d18e3085d0300b6678615d904d'
+end
+
+def temperature_in_city(this, name)
+  name = Truffle::Interop.from_java_string(name)
+  weather = Openweather2.get_weather(city: name, units: 'metric')
+  weather.temperature
+end
+
+Truffle::Interop.export_method :temperature_in_city
