add merge line

VERSION

@@ -1 +1 @@
-0.7.2
+0.7.3

lib/postgis_adapter/acts_as_geom.rb

@@ -24,6 +24,7 @@ def has_geom(*geom)
         when :point       then  PointFunctions
         when :polygon     then PolygonFunctions
         when :line_string then  LineStringFunctions
+        when :multi_line_string then MultiLineStringFunctions
       end unless geom[0].kind_of? Symbol
     end
     alias :acts_as_geom :has_geom

lib/postgis_functions/common.rb

@@ -664,10 +664,6 @@ def interpolate_point(fraction)
       postgis_calculate(:line_interpolate_point, self, fraction)
     end
 
-    def line_merge
-      postgis_calculate(:line_merge, self)
-    end
-
     #
     # Return a linestring being a substring of the input one starting and ending
     # at the given fractions of total 2d length. Second and third arguments are
@@ -693,7 +689,20 @@ def line_substring(s,e)
     #end
   end
 
+  module MultiLineStringFunctions
 
+    #
+    # Returns a (set of) LineString(s) formed by sewing together a MULTILINESTRING.
+    #
+    # Only use with MULTILINESTRING/LINESTRINGs. If you feed a polygon or geometry collection into this function, it will return an empty GEOMETRYCOLLECTION
+    #
+    # Returns geometry ST_LineMerge(geometry amultilinestring);
+    #
+    def line_merge
+      postgis_calculate(:lineMerge, self)
+    end
+
+  end
   #
   #
   #

spec/db/models_postgis.rb

@@ -52,6 +52,10 @@ class Street < ActiveRecord::Base
   acts_as_geom :geom => :line_string
 end
 
+class Road < ActiveRecord::Base
+  acts_as_geom :geom => :multi_line_string
+end
+
 class CommonGeo < ActiveRecord::Base
   acts_as_geom :geom => :point
 end

spec/db/schema_postgis.rb

@@ -78,6 +78,12 @@
     t.line_string   :geom, :null => false, :srid => 4326
   end
 
+  create_table :roads, :force => true do |t|
+    t.string              :data, :limit => 100
+    t.integer             :value
+    t.multi_line_string   :geom, :null => false, :srid => 4326
+  end
+
   create_table :common_geos, :force => true do |t|
     t.string        :data, :limit => 100
     t.integer       :value

spec/postgis_functions/common_spec.rb

@@ -8,6 +8,7 @@
     @c2 ||= City.create!(:data => "City1", :geom => Polygon.from_coordinates([[[22,66],[65,65],[20,10],[22,66]],[[10,15],[15,11],[34,14],[10,15]]],4326))
     @c3 ||= City.create!(:data => "City3", :geom => Polygon.from_coordinates([[[12.4,-45.3],[45.4,41.6],[4.456,1.0698],[12.4,-45.3]],[[2.4,5.3],[5.4,1.4263],[14.46,1.06],[2.4,5.3]]],4326))
     @s1 ||= Street.create!(:data => "Street1", :geom => LineString.from_coordinates([[1,1],[2,2]],4326))
+    @sx ||= Street.create!(:data => "Street1", :geom => LineString.from_coordinates([[2,2],[4,4]],4326))
     @s2 ||= Street.create!(:data => "Street2", :geom => LineString.from_coordinates([[4,4],[7,7]],4326))
     @s3 ||= Street.create!(:data => "Street3", :geom => LineString.from_coordinates([[8,8],[18,18],[20,20],[25,25],[30,30],[38,38]],4326))
     @s4 ||= Street.create!(:data => "Street4", :geom => LineString.from_coordinates([[10,8],[15,18]],4326))
@@ -16,6 +17,8 @@
     @p3 ||= Position.create!(:data => "Point3", :geom => Point.from_x_y(8,8,4326))
     @p4 ||= Position.create!(:data => "Point4", :geom => Point.from_x_y(18.1,18,4326))
     @p5 ||= Position.create!(:data => "Point5", :geom => Point.from_x_y(30,30,4326))
+    @m1 ||= Road.create(:data => "MG-050", :geom => MultiLineString.from_line_strings([@s1.geom, @sx.geom]))
+    @m2 ||= Road.create(:data => "MG-050", :geom => MultiLineString.from_line_strings([@s3.geom, @s4.geom]))
   end
 
   describe "Point" do
@@ -239,6 +242,10 @@
       end
     end
 
+    it "should have 1 geometry" do
+      @s1.should_not respond_to(:geometries)
+    end
+
     it "should intersect with linestring" do
       @s4.intersects?(@s3).should be_true
     end
@@ -293,7 +300,6 @@
           @s1.as_geo_json.should eql("{\"type\":\"LineString\",\"coordinates\":[[1,1],[2,2]]}")
         end
       end
-
     end
 
     describe "Distance" do
@@ -369,6 +375,24 @@
       str.geom[1].x.should be_close(7,0.0000001)
       str.geom[1].y.should be_close(7,0.0000001)
     end
+
+    describe "MultiLineString" do
+
+      it "should write nicely" do
+        @m1.geom.should be_instance_of(MultiLineString)
+      end
+
+      it "should have 2 geometries" do
+        @m1.geom.should have(2).geometries
+      end
+
+      it "should line merge!" do
+        merged = @m1.line_merge
+        p merged, @m1.geom
+        merged.should be_instance_of(LineString)
+        p merged.class
+      end
+    end
   end
 
 end