Refactored header_footer element serialization.

This adds a serializable_element_attributes helper that should be
integrated as we have time for serializing child elements that are
based on object attributes.

2 files changed, 34 insertions, 12 deletions

diff --git a/lib/axlsx/util/serialized_attributes.rb b/lib/axlsx/util/serialized_attributes.rb
index bffa0a10..3372dd5c 100644
--- a/lib/axlsx/util/serialized_attributes.rb
+++ b/lib/axlsx/util/serialized_attributes.rb
@@ -21,6 +21,14 @@ module Axlsx
       def xml_attributes
         @xml_attributes
       end
+
+      def serializable_element_attributes(*symbols)
+        @xml_element_attributes = symbols
+      end
+
+      def xml_element_attributes
+        @xml_element_attributes
+      end
     end
 
     # serializes the instance values of the defining object based on the 
@@ -36,11 +44,32 @@ module Axlsx
         key_value_pairs.delete(key) unless self.class.xml_attributes.include?(key.to_sym)
       end
       key_value_pairs.merge! additional_attributes
-
       key_value_pairs.each do |key, value|
         str << "#{Axlsx.camel(key, false)}=\"#{value}\" "
       end
       str
     end
+
+
+    # serialized instance values at text nodes on a camelized element of the
+    # attribute name. You may pass in a block for evaluation against non nil
+    # values. We use an array for element attributes becuase misordering will
+    # break the xml and 1.8.7 does not support ordered hashes.
+    # @param [String] str The string instance to which serialized data is appended
+    # @param [Array] additional_attributes An array of additional attribute names.
+    # @param [Proc] block A which will be called with the value for each element.
+    # @return [String] The serialized output.
+    def serialized_element_attributes(str='', additional_attributes=[], &block)
+      attrs = self.class.xml_element_attributes + additional_attributes
+      values = instance_values
+      attrs.each do |attribute_name|
+        value = values[attribute_name.to_s]
+        next if value.nil?
+        yield value if block_given?
+        element_name = Axlsx.camel(attribute_name, false)
+        str << "<#{element_name}>#{value}</#{element_name}>"
+      end
+      str
+    end
   end
 end
diff --git a/lib/axlsx/workbook/worksheet/header_footer.rb b/lib/axlsx/workbook/worksheet/header_footer.rb
index 20d7b0eb..a40ad853 100644
--- a/lib/axlsx/workbook/worksheet/header_footer.rb
+++ b/lib/axlsx/workbook/worksheet/header_footer.rb
@@ -28,7 +28,7 @@ module Axlsx
     end
 
     serializable_attributes :different_odd_even, :different_first
-
+    serializable_element_attributes :odd_header, :odd_footer, :even_header, :even_footer, :first_header, :first_footer
     string_attr_accessor :odd_header, :odd_footer, :even_header, :even_footer, :first_header, :first_footer
     boolean_attr_accessor :different_odd_even, :different_first
 
@@ -45,16 +45,9 @@ module Axlsx
       str << "<headerFooter "
       serialized_attributes str
       str << ">"
-
-      str << "<oddHeader>#{::CGI.escapeHTML(odd_header)}</oddHeader>" unless odd_header.nil?
-      str << "<oddFooter>#{::CGI.escapeHTML(odd_footer)}</oddFooter>" unless odd_footer.nil?
-
-      str << "<evenHeader>#{::CGI.escapeHTML(even_header)}</evenHeader>" unless even_header.nil?
-      str << "<evenFooter>#{::CGI.escapeHTML(even_footer)}</evenFooter>" unless even_footer.nil?
-
-      str << "<firstHeader>#{::CGI.escapeHTML(first_header)}</firstHeader>" unless first_header.nil?
-      str << "<firstFooter>#{::CGI.escapeHTML(first_footer)}</firstFooter>" unless first_footer.nil?
-
+      serialized_element_attributes(str) do |value|
+        value = ::CGI.escapeHTML(value)
+      end
       str << "</headerFooter>"
     end
   end