[#33] Add support for Dxf elements to enable conditional formatting

New Dxf class implements 18.8.14. Conditional formatting now "works".

Add :type option to add_styles, defaults to :xf

when add_styles is called with :dxf type, new styles are not added
to the global @styles set. Dxf child elements only exist inside the
`<dxf>` chunk.

Added tests and an example.

1 files changed, 77 insertions, 0 deletions

diff --git a/lib/axlsx/stylesheet/dxf.rb b/lib/axlsx/stylesheet/dxf.rb
new file mode 100644
index 00000000..ccd4cd95
--- /dev/null
+++ b/lib/axlsx/stylesheet/dxf.rb
@@ -0,0 +1,77 @@
+# encoding: UTF-8
+module Axlsx
+  # The Dxf class defines an incremental formatting record for use in Styles. The recommended way to manage styles for your workbook is with Styles#add_style
+  # @see Styles#add_style
+  class Dxf
+    # The order in which the child elements is put in the XML seems to
+    # be important for Excel
+    CHILD_ELEMENTS = [:font, :numFmt, :fill, :alignment, :border, :protection]
+    #does not support extList (ExtensionList)
+
+    # The cell alignment for this style
+    # @return [CellAlignment]
+    # @see CellAlignment
+    attr_reader :alignment
+
+    # The cell protection for this style
+    # @return [CellProtection]
+    # @see CellProtection
+    attr_reader :protection
+
+    # the child NumFmt to be used to this style
+    # @return [NumFmt]
+    attr_reader :numFmt
+
+    # the child font to be used for this style
+    # @return [Font]
+    attr_reader :font
+
+    # the child fill to be used in this style
+    # @return [Fill]
+    attr_reader :fill
+
+    # the border to be used in this style
+    # @return [Border]
+    attr_reader :border
+
+    # Creates a new Xf object
+    # @option options [Border] border
+    # @option options [NumFmt] numFmt
+    # @option options [Fill] fill
+    # @option options [Font] font
+    # @option options [CellAlignment] alignment
+    # @option options [CellProtection] protection
+    def initialize(options={})
+      options.each do |o|
+        self.send("#{o[0]}=", o[1]) if self.respond_to? "#{o[0]}="
+      end
+    end
+
+    # @see Dxf#alignment
+    def alignment=(v) DataTypeValidator.validate "Dxf.alignment", CellAlignment, v; @alignment = v end
+    # @see protection
+    def protection=(v) DataTypeValidator.validate "Dxf.protection", CellProtection, v; @protection = v end
+    # @see numFmt
+    def numFmt=(v) DataTypeValidator.validate "Dxf.numFmt", NumFmt, v; @numFmt = v end
+    # @see font
+    def font=(v) DataTypeValidator.validate "Dxf.font", Font, v; @font = v end
+    # @see border
+    def border=(v) DataTypeValidator.validate "Dxf.border", Border, v; @border = v end
+    # @see fill
+    def fill=(v) DataTypeValidator.validate "Dxf.fill", Fill, v; @fill = v end
+
+    # Serializes the object
+    # @param [String] str
+    # @return [String]
+    def to_xml_string(str = '')
+      str << '<dxf>'
+      # Dxf elements have no attributes. All of the instance variables
+      # are child elements.
+      CHILD_ELEMENTS.each do |element|
+        self.send(element).to_xml_string(str) if self.send(element)
+      end
+      str << '</dxf>'
+    end
+
+  end
+end