Airport weather

components/AirportWeather.coffee

@@ -0,0 +1,69 @@
+msgflo = require 'msgflo-nodejs'
+MetarFetcher = require('metar-taf').MetarFetcher
+metarFetcher = new MetarFetcher
+metarParser = require('metar')
+
+getWeather = (station, callback) ->
+  metarFetcher.getData(station)
+  .then (data) ->
+    clean = data.split("\n")[1]
+    callback null, metarParser clean
+  , (err) ->
+    callback err
+
+Participant = (client, role) ->
+  station = null
+  definition =
+    id: role
+    component: 'AirportWeather'
+    icon: 'plane'
+    label: 'Fetch weather data for an airport'
+    inports: [
+      id: 'icao'
+      type: 'string'
+      hidden: false
+    ,
+      id: 'fetch'
+      type: 'bang'
+      hidden: false
+    ,
+      id: 'temperature'
+      type: 'float'
+      hidden: true
+    ,
+      id: 'pressure'
+      type: 'float'
+      hidden: true
+    ]
+    outports: [
+      id: 'temperature'
+      type: 'float'
+      hidden: false
+    ,
+      id: 'pressure'
+      type: 'float'
+      hidden: false
+    ,
+      id: 'error'
+      type: 'object'
+      hidden: false
+    ]
+  process = (inport, indata, callback) ->
+    if inport in ['temperature', 'pressure']
+      # Forward to outport
+      return callback inport, null, indata
+    unless inport in ['icao', 'fetch']
+      return callback 'error', new Error "Unknown port name"
+    if inport is 'icao'
+      station = indata
+    if inport is 'fetch' and station is null
+      return callback 'error', new Error "No weather station provided"
+    getWeather station, (err, weather) ->
+      return callback 'error', err if err
+      participant.send 'pressure', weather.altimeterInHpa
+      callback 'temperature', null, weather.temperature
+
+  participant = new msgflo.participant.Participant client, definition, process, role
+  return participant
+
+module.exports = Participant

package.json

@@ -20,6 +20,8 @@
   "dependencies": {
     "coffee-script": "^1.10.0",
     "fbp": "^1.5.0",
+    "metar": "^1.0.0",
+    "metar-taf": "0.0.2",
     "mqtt": "~2.8.0",
     "msgflo": "^0.10.19",
     "msgflo-nodejs": "^0.10.5"

spec/AirportWeather.yaml

@@ -0,0 +1,17 @@
+name: 'Oslo airport weather'
+topic: AirportWeather
+fixture:
+  type: 'fbp'
+  data: |
+    INPORT=weather.ICAO:ICAO
+    OUTPORT=weather.TEMPERATURE:TEMPERATURE
+    weather(AirportWeather)
+cases:
+-
+  name: 'fetching weather'
+  assertion: 'should return a temperature'
+  inputs:
+    icao: ENGM
+  expect:
+    temperature:
+      type: number