lib/postgis_functions.rb in nofxx-postgis_adapter-0.3.1 vs lib/postgis_functions.rb in nofxx-postgis_adapter-0.3.3

@@ -9,17 +9,17 @@
 # http://nofxx.lighthouseapp.com/projects/20712-postgisadapter
 #
 #
 # Some links:
 #
-# PostGis Manual -  http://postgis.refractions.net/documentation/manual-svn/ch07.html
+# PostGis Manual - http://postgis.refractions.net/documentation/manual-svn/ch07.html
 # Earth Spheroid - http://en.wikipedia.org/wiki/Figure_of_the_Earth
 #
-#
+
 module PostgisFunctions
+  # WGS84 Spheroid
   EARTH_SPHEROID = "'SPHEROID[\"GRS-80\",6378137,298.257222101]'" # SRID => 4326
-  #EARTH_SPHEROID = "'SPHEROID[\"IERS_2003\",6378136.6,298.25642]'" # SRID =>
 
   def postgis_calculate(operation, subjects, options = {})
     subjects = [subjects] unless subjects.respond_to?(:map)
     return execute_geometrical_calculation(operation, subjects, options)
     rescue Exception => e
@@ -27,19 +27,19 @@
   end
 
   private
 
   def get_column_name
-    @geo_column ||= postgis_geoms[:columns].first
+    @geo_column ||= postgis_geoms[:columns]
   end
 
   #
-  # Construct the postgis sql query
+  # Construct the PostGIS SQL query
   #
-  # Area return in square feet
-  # Distance/DWithin/Length/Perimeter —  in projected units.
-  # DistanceSphere/Spheroid —  in meters.
+  # Returns:
+  # Area/Distance/DWithin/Length/Perimeter  =>  projected units
+  # DistanceSphere/Spheroid  =>  meters
   #
   def construct_geometric_sql(type,geoms,options)
 
     tables = geoms.map do |t| {
       :name => t.class.table_name,
@@ -54,11 +54,11 @@
     end
 
     fields      = tables.map { |f| "#{f[:uid]}.#{get_column_name}" }     # W1.geom
     fields.map! { |f| "ST_Transform(#{f}, #{transform})" } if transform  # ST_Transform(W1.geom,x)
     conditions  = tables.map { |f| "#{f[:uid]}.id = #{f[:id]}" }         # W1.id = 5
-    tables.map! { |f| "#{f[:name]} #{f[:uid]}" }                        # streets W1
+    tables.map! { |f| "#{f[:name]} #{f[:uid]}" }                         # streets W1
 
     #
     # Data  =>  SELECT Func(A,B)
     # BBox  =>  SELECT (A <=> B)
     # Func  =>  SELECT Func(Func(A))
@@ -147,10 +147,10 @@
 #ST_AsEWKT
 #ST_AsHEXEWKB
 #ST_AsGML
 #ST_AsKML
 #ST_AsSVG
-#
+#  #EARTH_SPHEROID = "'SPHEROID[\"IERS_2003\",6378136.6,298.25642]'" # SRID =>
 #  def distance_convert(value, unit, from = nil)
 #    factor = case unit
 #    when :km, :kilo     then  1
 #    when :miles,:mile   then  0.62137119
 #    when :cm, :cent     then  0.1