-
-
Save rafaltrojanowski/4f634d0df804af86dacadb6d2146b4e2 to your computer and use it in GitHub Desktop.
Weather-O-Rama Inc.’s next generation, Internet-based Weather Monitoring Station
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
module Subject | |
def register_observer() | |
raise NotImplementedError | |
end | |
def remove_observer() | |
raise NotImplementedError | |
end | |
def notify_observers() | |
raise NotImplementedError | |
end | |
end | |
module Observer | |
def update() | |
raise NotImplementedError | |
end | |
end | |
module DisplayElement | |
def display() | |
raise NotImplementedError | |
end | |
# UTF-8 encoding table and Unicode characters | |
# http://www.utf8-chartable.de/unicode-utf8-table.pl?start=9472&unicodeinhtml=dec | |
def box(title, body, width=78) | |
lines = [] | |
lines << "╔%s╗" % ( "[ #{title} ]".center(width, "═") ) | |
lines << "║%s║" % ( "░" * width ) | |
lines << "║%s║" % ( " #{body} ".center(width, "░") ) | |
lines << "║%s║" % ( "░" * width ) | |
lines << "╚%s╝" % ( "═" * width ) | |
lines.join("\n") | |
end | |
end | |
### | |
class WeatherData | |
include Subject | |
attr_reader :temperature, :humidity, :pressure | |
attr_reader :observers | |
def initialize | |
@observers = [] | |
end | |
def register_observer(observer) | |
observers.push(observer) | |
end | |
def remove_observer(observer) | |
observers.delete(observer) | |
end | |
def notify_observers() | |
observers.each(&:update) | |
end | |
def measurements_changed() | |
notify_observers() | |
end | |
def set_measurements(temperature, humidity, pressure) | |
@temperature = temperature | |
@humidity = humidity | |
@pressure = pressure | |
measurements_changed() | |
end | |
end | |
class CurrentConditionsDisplay | |
include Observer | |
include DisplayElement | |
attr_reader :temperature, :humidity | |
attr_reader :weather_data | |
def initialize(weather_data) | |
@weather_data = weather_data | |
@weather_data.register_observer(self) | |
end | |
def update() | |
@temperature = weather_data.temperature | |
@humidity = weather_data.humidity | |
display() | |
end | |
def display() | |
title = "Current Conditions" | |
body = "#{temperature} F degrees and #{humidity}% humidity" | |
puts box(title, body) | |
end | |
end | |
class ForecastDisplay | |
include Observer | |
include DisplayElement | |
attr_reader :current_pressure, :last_pressure | |
attr_reader :weather_data | |
def initialize(weather_data) | |
@current_pressure = 29.92 | |
@weather_data = weather_data | |
@weather_data.register_observer(self) | |
end | |
def update() | |
@last_pressure = current_pressure | |
@current_pressure = weather_data.pressure | |
display() | |
end | |
def display() | |
title = "Forecast" | |
body = if current_pressure > last_pressure | |
"Improving weather on the way!" | |
elsif current_pressure < last_pressure | |
"Watch out for cooler, rainy weather" | |
else | |
"More of the same" | |
end | |
puts box(title, body) | |
end | |
end | |
class StatisticsDisplay | |
include Observer | |
include DisplayElement | |
attr_reader :max_temp, :min_temp, :temp_sum, :num_readings | |
attr_reader :weather_data | |
def initialize(weather_data) | |
@max_temp = 0 | |
@min_temp = 200 | |
@temp_sum = 0 | |
@num_readings = 0 | |
@weather_data = weather_data | |
@weather_data.register_observer(self) | |
end | |
def update() | |
@temp_sum += weather_data.temperature | |
@num_readings += 1 | |
if weather_data.temperature > @max_temp | |
@max_temp = weather_data.temperature | |
end | |
if weather_data.temperature < @min_temp | |
@min_temp = weather_data.temperature | |
end | |
display() | |
end | |
def display() | |
title = "Statistics" | |
body = "Avg/Max/Min temperature = %s/%s/%s" | |
body = body % [temp_sum/num_readings, max_temp, min_temp] | |
puts box(title, body) | |
end | |
end | |
class HeatIndexDisplay | |
include Observer | |
include DisplayElement | |
attr_reader :heat_index | |
attr_reader :weather_data | |
def initialize(weather_data) | |
@weather_data = weather_data | |
@weather_data.register_observer(self) | |
end | |
def update() | |
@heat_index = compute_heat_index( | |
weather_data.temperature, | |
weather_data.humidity | |
) | |
display() | |
end | |
# The Heat Index Equation | |
# http://www.hpc.ncep.noaa.gov/html/heatindex_equation.shtml | |
def compute_heat_index(t, rh) | |
-42.379 + 2.04901523*t + 10.14333127*rh - 0.22475541*t*rh - | |
0.00683783*t*t - 0.05481717*rh*rh + 0.00122874*t*t*rh + | |
0.00085282*t*rh*rh - 0.00000199*t*t*rh*rh | |
end | |
def display() | |
title = "Heat Index" | |
body = "Heat index is %.2f" % @heat_index | |
puts box(title, body) | |
end | |
end | |
### | |
class WeatherStation | |
def self.start() | |
weather_data = WeatherData.new | |
current_display = CurrentConditionsDisplay.new(weather_data) | |
forecase_display = ForecastDisplay.new(weather_data) | |
statistics_display = StatisticsDisplay.new(weather_data) | |
heat_display = HeatIndexDisplay.new(weather_data) | |
weather_data.set_measurements(80, 65, 30.4) | |
weather_data.set_measurements(82, 70, 29.2) | |
weather_data.set_measurements(78, 90, 29.2) | |
end | |
end | |
if $0 == __FILE__ | |
WeatherStation.start() | |
end |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment