From f0b45448f35384857e3ff9eccb5770756709b742 Mon Sep 17 00:00:00 2001
From: Adam Burmister <adam.burmister@gmail.com>
Date: Thu, 8 Nov 2012 15:21:43 +0000
Subject: [PATCH] Allow default values via  attributes on TDs. If there is a
 parse error return the val unparsed.

---
 README.textile            |  4 ++++
 lib/to_spreadsheet/xls.rb | 43 +++++++++++++++++++++++++++------------
 spec/xls_spec.rb          | 12 +++++++++--
 3 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/README.textile b/README.textile
index ae78990..884c330 100644
--- a/README.textile
+++ b/README.textile
@@ -59,6 +59,10 @@ You can use class names on td/th for typed values. Here is the list of class to
 | date             | Date     |
 | time             | Time     |
 
+h3. Default null values
+
+Add a `data-null="default value"` attribute to a cell to use the value as a default if the model value is nil.
+
 h3. Worksheets
 
 Every table in the view will be converted to a separate sheet.
diff --git a/lib/to_spreadsheet/xls.rb b/lib/to_spreadsheet/xls.rb
index ef9182b..a4767df 100644
--- a/lib/to_spreadsheet/xls.rb
+++ b/lib/to_spreadsheet/xls.rb
@@ -22,21 +22,38 @@ def to_io(html)
     private
 
     def typed_node_val(node)
+      val = val_or_null_default(node)
+      
+      return '' if !val
+
+      begin
+        case node[:class]
+          when /decimal|float/
+            val.to_f
+          when /num|int/
+            val.to_i
+          when /datetime/
+            DateTime.parse(val)
+          when /date/
+            Date.parse(val)
+          when /time/
+            Time.parse(val)
+          else
+            val
+        end
+      rescue
+        val
+      end
+    end
+
+    def val_or_null_default(node)
       val = node.inner_text
-      case node[:class]
-        when /decimal|float/
-          val.to_f
-        when /num|int/
-          val.to_i
-        when /datetime/
-          DateTime.parse(val)
-        when /date/
-          Date.parse(val)
-        when /time/
-          Time.parse(val)
-        else
-          val
+      if val.blank?
+        node['data-null']
+      else
+        val
       end
     end
+
   end
 end
diff --git a/spec/xls_spec.rb b/spec/xls_spec.rb
index 8a5c342..207ac23 100644
--- a/spec/xls_spec.rb
+++ b/spec/xls_spec.rb
@@ -23,6 +23,14 @@
     spreadsheet.worksheet(0)[1, 2].class.should be(Date)
   end
 
+  it 'parses null dates' do
+    spreadsheet.worksheet(0)[2, 2].class.should_not be(Date)
+  end
+
+  it 'parses default values' do
+    spreadsheet.worksheet(0)[2, 1].should == 100
+  end
+
   # This is for final manual test
   # The test spreadsheet will be saved to /tmp/spreadsheet.xls
   it 'writes to disk' do
@@ -49,8 +57,8 @@
       %td.date 27/05/1991
     %tr
       %td John
-      %td.num 21
-      %td.date 01/05/1990
+      %td.num{ data: { null: 100 } }
+      %td.date
 
 %table
   %caption Another worksheet