each example: weather_forecast.js

This example queries the Yahoo! Weather RSS feed for locations in a list of major cities, displaying the returned weather conditions for each.

The state machines only state, MajorCityWeather, uses the each plug-in to iterate over a list of WOEID (Where On Earth ID) codes representing the city locations. At each iteration the yahooapis.request function is called with arguments generated by the fnArgs function.

When a response from any RSS request is received the iterator function is called which simply dumps the returned data to the console. The par parameter is used to set the maximum number of requests made in parallel to no more than 6.

var yahooapis = require('../../weather_yahooapis');

function weatherForecast (fire, woeidArray) {
  this.startState = 'MajorCityWeather';
  this.states = {
    MajorCityWeather: {
      each: {
        fn: 'request',
        fnArgs: function (woied) {
          return { 'w': woied, 'u': 'c' };
        },        
        iterator: function (itr, err, data) {
          if (err) {
            console.error(err);
          } else {
            console.log('%s', data);
          }
        },
        par: 6
      },
      actions: {
        '.done': '@exit'
      }
    }
  };
};

weatherForecast.defaults = {
  imports: { request: yahooapis.request },
  args: [ yahooapis.majorCities ]
};

module.exports = weatherForecast;

Example Output

The source code for the example can be found in the file examples/plugins/each/weather_forecast.js and run using the ignite command line helper application as follows:

 $ ./bin/ignite examples/plugins/each/weather_forecast.js
 Running examples/plugins/each/weather_forecast.js
 London, United Kingdom: 18C Partly Cloudy
 Paris, France: 20C Mostly Cloudy
 Mosco, Mexico: 16C Mostly Cloudy
 Beijing, China: 26C Fair
 Tokyo, Japan: 29C Mostly Cloudy
 Mumbai, India: 31C Haze
 San Fransisco, Spain: 27C Partly Cloudy
 New York, United States: 23C Partly Cloudy
 Barcelona, Spain: 27C Partly Cloudy
 Texas, United States: 21C Fair
 Seoul, South Korea: 27C Cloudy
 Sao Paulo, Brazil: 11C Fair
 Jakarta, Indonesia: 29C Partly Cloudy
 Karachi, Pakistan: 33C Mostly Cloudy
 Istanbul, Turkey: 28C Partly Cloudy
 Mexico, Mexico: 16C Mostly Cloudy
 Shanghai, China: 30C Mostly Cloudy
 Bangkok, Thailand: 31C Light Rain
 New Delhi, India: 31C Fog
 Hong Kong, Hong Kong: 33C Partly Cloudy
 run: examples/plugins/each/weather_forecast.js Exited with no error.
 $ _

See