Fixes Issue #202 Axes are borked in Bar3DChart

2 files changed, 19 insertions, 1 deletions

diff --git a/lib/axlsx/drawing/axes.rb b/lib/axlsx/drawing/axes.rb
index c3a8dd85..fc440b1a 100644
--- a/lib/axlsx/drawing/axes.rb
+++ b/lib/axlsx/drawing/axes.rb
@@ -28,7 +28,9 @@ module Axlsx
     # serialized. Otherwise, each axis is serialized in full. 
     def to_xml_string(str = '', options = {})
       if options[:ids]
-        axes.inject(str) { |string, axis| string << '<c:axId val="' << axis[1].id.to_s << '"/>' }
+        # CatAxis must come first in the XML (for Microsoft Excel at least)
+        sorted = axes.sort_by { |name, axis| axis.kind_of?(CatAxis) ? 0 : 1 }
+        sorted.inject(str) { |string, axis| string << '<c:axId val="' << axis[1].id.to_s << '"/>' }        
       else
         axes.each { |axis| axis[1].to_xml_string(str) }
       end
diff --git a/test/drawing/tc_axes.rb b/test/drawing/tc_axes.rb
new file mode 100644
index 00000000..caa242ad
--- /dev/null
+++ b/test/drawing/tc_axes.rb
@@ -0,0 +1,16 @@
+require 'tc_helper.rb'
+
+class TestAxes < Test::Unit::TestCase
+  def setup
+    @axes = Axlsx::Axes.new(:val_axis => Axlsx::ValAxis, :cat_axis => Axlsx::CatAxis)
+  end
+
+  def test_to_xml_string_just_ids
+    str  = '<?xml version="1.0" encoding="UTF-8"?>'
+    str << '<c:chartSpace xmlns:c="' << Axlsx::XML_NS_C << '" xmlns:a="' << Axlsx::XML_NS_A << '">'
+    @axes.to_xml_string(str, :ids => true)
+    cat_axis_position = str.index(@axes[:cat_axis].id.to_s)
+    val_axis_position = str.index(@axes[:val_axis].id.to_s)
+    assert(cat_axis_position < val_axis_position, "cat_axis must occur earlier than val_axis in the XML")
+  end
+end
\ No newline at end of file