System.Taffybar.Weather

Contents

Description

This module defines a simple textual weather widget that polls NOAA for weather data. To find your weather station, you can use

 http://lwf.ncdc.noaa.gov/oa/climate/stationlocator.html

For example, Madison, WI is KMSN.

NOAA provides several pieces of information in each request; you can control which pieces end up in your weather widget by providing a _template_ that is filled in with the current information. The template is just a String with variables between dollar signs. The variables will be substituted with real data by the widget. Example:

 let wcfg = (defaultWeatherConfig "KMSN") { weatherTemplate = "$tempC$ C @ $humidity$" }
     weatherWidget = weatherNew wcfg 10

This example makes a new weather widget that checks the weather at KMSN (Madison, WI) every 10 minutes, and displays the results in Celcius.

Available variables:

stationPlace: The name of the weather station
stationState: The state that the weather station is in
year: The year the report was generated
month: The month the report was generated
day: The day the report was generated
hour: The hour the report was generated
wind: The direction and strength of the wind
visibility: Description of current visibility conditions
skyCondition: ?
tempC: The temperature in Celcius
tempF: The temperature in Farenheit
dewPoint: The current dew point
humidity: The current relative humidity
pressure: The current pressure

As an example, a template like

 "$tempF$ F"

would yield a widget displaying the temperature in Farenheit with a small label after it.

Implementation Note: the weather data parsing code is taken from xmobar. This version of the code makes direct HTTP requests instead of invoking a separate cURL process.

Synopsis

Types

data WeatherConfig Source

The configuration for the weather widget. You can provide a custom format string through weatherTemplate as described above, or you can provide a custom function to turn a WeatherInfo into a String via the weatherFormatter field.

Constructors

WeatherConfig
Fields weatherStation :: String The weather station to poll. No default weatherTemplate :: String Template string, as described above. Default: $tempF$ F weatherFormatter :: WeatherFormatter Default: substitute in all interpolated variables (above)

data WeatherInfo Source

Constructors

WI
Fields stationPlace :: String stationState :: String year :: String month :: String day :: String hour :: String wind :: String visibility :: String skyCondition :: String tempC :: Int tempF :: Int dewPoint :: String humidity :: Int pressure :: Int

Instances

Show WeatherInfo

data WeatherFormatter Source

A wrapper to allow users to specify a custom weather formatter. The default interpolates variables into a string as described above. Custom formatters can do basically anything.

Constructors

WeatherFormatter (WeatherInfo -> String)

Specify a custom formatter for WeatherInfo

Constructor

weatherNew Source

Arguments

:: WeatherConfig	Configuration to render
-> Double	Polling period in _minutes_
-> IO Widget

Create a periodically-updating weather widget that polls NOAA.

defaultWeatherConfig :: String -> WeatherConfig Source

A sensible default configuration for the weather widget that just renders the temperature.