Add generator support for groups.

* Make sure we're reading out of groups in the data hash.
* Small bugfix in generator; Array() doesn't do what I thought with a hash.

lib/fixed_width/generator.rb

@@ -9,8 +9,9 @@ def generate(data)
       @builder = []
       @definition.sections.each do |section|
         content = data[section.name]
+        arrayed_content = content.is_a?(Array) ? content : [content]
         raise FixedWidth::RequiredSectionEmptyError.new("Required section '#{section.name}' was empty.") if (content.nil? || content.empty?) && !section.optional
-        Array(content).each {|row| @builder << section.format(row) }
+        arrayed_content.each {|row| @builder << section.format(row) }
       end
       @builder.join("\n")
     end

lib/fixed_width/section.rb

@@ -43,7 +43,10 @@ def template(name)
     end
 
     def format(data)
-      @columns.map{|column| column.format(data[column.name]) }.join
+      @columns.map do |c|
+        hash = c.group ? data[c.group] : data
+        c.format(hash[c.name])
+      end.join
     end
 
     def parse(line)

spec/generator_spec.rb

@@ -20,7 +20,7 @@
       end
     end
     @data = {
-      :header => [ {:type => "HEAD", :file_id => "1" }],
+      :header => [ {:type => "HEAD", :file_id => "1" } ],
       :body => [ 
         {:first => "Paul", :last => "Hewson" },
         {:first => "Dave", :last => "Evans" }
@@ -39,4 +39,10 @@
     expected = "HEAD         1\n      Paul    Hewson\n      Dave     Evans\nFOOT         1"
     @generator.generate(@data).should == expected
   end
+
+  it "should handle lazy data declaration (no array around single record for a section)" do
+    expected = "HEAD         1\n      Paul    Hewson\n      Dave     Evans\nFOOT         1"
+    @data[:header] = @data[:header].first
+    @generator.generate(@data).should == expected
+  end
 end

spec/section_spec.rb

@@ -115,6 +115,13 @@
       @section.column(:name, 10, :align => :left)
       @section.format(@data).should == "    3Ryan      "
     end
+
+    it "should read from groups" do
+      @data = { :id => 3, :foo => { :name => "Ryan" } }
+      @section.column(:id, 5)
+      @section.column(:name, 10, :align => :left, :group => :foo)
+      @section.format(@data).should == "    3Ryan      "
+    end
   end
 
   describe "when parsing a file" do