Revise atmosphere barometer to reflect tri-state.

- revise atmosphere.barometer to reflect tri-state as "steady",
  "rising", or "falling" via one of the new
  YahooWeather::Atmosphere::Barometer constants, whereas previously it
  was simply a boolean for whether rising.  Thanks to Andy Weber for
  suggestion.

CHANGELOG.rdoc

@@ -1,3 +1,9 @@
+* [shaper] revise atmosphere.barometer to reflect tri-state as
+  "steady", "rising", or "falling" via one of the new
+  YahooWeather::Atmosphere::Barometer constants, whereas previously it
+  was simply a boolean for whether rising.  Thanks to Andy Weber for
+  suggestion.
+
 = YAHOO_WEATHER_20091021_1_0_1
 
 * [shaper] update documentation to reflect reality and use suffix for

lib/yahoo-weather.rb

@@ -98,6 +98,17 @@ def initialize (payload)
 
   # Describes the specific atmospheric conditions at a location.
   class Atmosphere
+    # Constants representing the state of the barometric pressure.
+    #
+    class Barometer
+      STEADY = 'steady'
+      RISING = 'rising'
+      FALLING = 'falling'
+
+      # lists all possible barometer constants
+      ALL = [ STEADY, RISING, FALLING ]
+    end
+
     # the humidity of the surroundings.
     attr_reader :humidity
 
@@ -107,14 +118,22 @@ class Atmosphere
     # the pressure level of the surroundings.
     attr_reader :pressure
 
-    # whether the air currents are rising.
-    attr_reader :rising
-
+    # the state of the barometer, defined as one of the
+    # YahooWeather::Atmosphere::Barometer constants.
+    attr_reader :barometer
+
     def initialize (payload)
       @humidity = payload['humidity'].to_i
       @visibility = payload['visibility'].to_i
       @pressure = payload['pressure'].to_f
-      @rising = (payload['rising'] == "1")
+
+      # map barometric pressure direction to appropriate constant
+      @barometer = nil
+      case payload['rising'].to_i
+      when 0: @barometer = Barometer::STEADY
+      when 1: @barometer = Barometer::RISING
+      when 2: @barometer = Barometer::FALLING
+      end
     end
   end
 

test/test_api.rb

@@ -72,7 +72,7 @@ def _assert_valid_response (response, request_location, units, city, region, cou
     assert_kind_of Numeric, response.atmosphere.humidity
     assert_kind_of Numeric, response.atmosphere.visibility
     assert_kind_of Numeric, response.atmosphere.pressure
-    assert(response.atmosphere.rising.is_a?(TrueClass) || response.atmosphere.rising.is_a?(FalseClass))
+    assert(YahooWeather::Atmosphere::Barometer::ALL.include?(response.atmosphere.barometer))
 
     # check the condition info
     assert_instance_of YahooWeather::Condition, response.condition