modified collection.rb to parse rels and alternates

in order to parse relative URLs in rels, we need to parse the base/@href of
the page if there, or to pass the URL in, so added the relevant stuff to support
that.

lib/microformats2/collection.rb

@@ -2,13 +2,25 @@ module Microformats2
   class Collection
     attr_reader :all
 
-    def initialize(element)
+    def initialize(element, url = nil)
       @element = element
+      
+      @base = nil
+      if url != nil
+        @base = url
+      end
+      if @element.search("base").size > 0
+        @base = @element.search("base")[0].attribute("href")
+      end
+      
       @format_names = []
+      @rels = {}
+      @alternates = []
     end
 
     def parse
       all
+      parse_rels
       self
     end
 
@@ -29,10 +41,12 @@ module Microformats2
     end
 
     def to_hash
-      hash = { items: [] }
+      hash = { items: [], rels: @rels }
       all.each do |format|
         hash[:items] << format.to_hash
       end
+      hash[:alternates] = @alternates unless @alternates.nil? || @alternates.empty?
+      
       hash
     end
 
@@ -67,5 +81,40 @@ module Microformats2
         send("#{mn.pluralize}=", [value])
       end
     end
+    
+    def parse_rels
+      @element.search("*[@rel]").each do |rel|
+        rel_values = rel.attribute("rel").text.split(" ")
+        
+        if rel_values.member?("alternate")
+          alternate_inst = {}
+          alternate_inst["url"] = absolutize(rel.attribute("href").text)
+          alternate_inst["rel"] = (rel_values - ["alternate"]).join(" ")
+          unless rel.attribute("media").nil?
+            alternate_inst["media"] = rel.attribute("media").text
+          end
+          unless rel.attribute("hreflang").nil?
+            alternate_inst["hreflang"] = rel.attribute("hreflang").text
+          end
+          unless rel.attribute("type").nil?
+            alternate_inst["type"] = rel.attribute("type").text
+          end
+          @alternates << alternate_inst
+        else
+          rel_values.each do |rel_value|
+            @rels[rel_value] = [] unless @rels.has_key?(rel_value)
+            @rels[rel_value] << absolutize(rel.attribute("href").text)
+          end
+        end
+      end
+    end
+    
+    def absolutize(href)
+      if URI.parse(href).absolute?
+        href
+      else
+        URI.join(@base, href).to_s
+      end
+    end
   end
 end