added switching to euro date formats instead of US

README

@@ -129,6 +129,8 @@ you want. No regular expressions or duck punching (monkey patching) the plugin.
     d.m.yy
     d mmm yy
   
+  NOTE: to switch to using non-US date formats see US/EURO FORMATS section
+  
   Datetime formats:  
     m/d/yy h:nn:ss   OR  d/m/yy hh:nn:ss
     m/d/yy h:nn      OR  d/m/yy h:nn
@@ -138,6 +140,8 @@ you want. No regular expressions or duck punching (monkey patching) the plugin.
     ddd mmm d hh:nn:ss zo yyyy # Ruby time string
     yyyy-mm-ddThh:nn:ss(?:Z|zo) # ISO 8601
 
+  NOTE: to switch to using non-US date formats see US/EURO FORMATS section
+
 Here is what each format token means:
 
   Format tokens:   
@@ -177,6 +181,21 @@ regular expressions directly. So, no, it won't make your app slow!
 
 To see all defined formats look in the lib/validates_timeliness/formats.rb.
 
+=== US/EURO FORMATS
+
+The perenial problem for non-US develops or applications not primarily for the
+US, is the US date format of m/d/yy. This is ambiguous with the European format
+of d/my/yy. By default the plugin uses the US formats as this is the Ruby default
+when it does date interpretation, and is in keeping PoLS (principle of least
+surprise). 
+
+To switch to using the European (or Rest of The World) formats put this in an
+initializer or environment.rb
+
+  ValidatesTimeliness::Formats.remove_us_formats  
+
+Now '01/02/2000' will be parsed as 1st February 2000, instead of 2nd January 2000.
+
 === CUSTOMISING FORMATS:
 
 I hear you say "Thats greats but I don't want X format to be valid". Well to 

lib/validates_timeliness/formats.rb

@@ -1,4 +1,3 @@
-# TODO add support switching US to euro date formats
 module ValidatesTimeliness
   
   # A date and time format regular expression generator. Allows you to 
@@ -230,8 +229,8 @@ module ValidatesTimeliness
       
       # Adds new formats. Must specify format type and can specify a :before
       # option to nominate which format the new formats should be inserted in 
-      # front on to take higher precedence. Error is raise if format already 
+      # front on to take higher precedence. 
-      # exists or if :before format is not found.
+      # Error is raise if format already exists or if :before format is not found.
       def add_formats(type, *add_formats)
         formats = self.send("#{type}_formats")
         options = {}
@@ -248,6 +247,17 @@ module ValidatesTimeliness
         compile_format_expressions
       end
       
+      
+      # Removes formats where the 1 or 2 digit month comes first, to eliminate
+      # formats which are ambiguous with the European style of day then month. 
+      # The mmm token is ignored as its not ambigous.
+      def remove_us_formats
+        us_format_regexp = /\Am{1,2}[^m]/
+        date_formats.reject! { |format| us_format_regexp =~ format }
+        datetime_formats.reject! { |format| us_format_regexp =~ format }
+        compile_format_expressions
+      end
+      
       def full_hour(hour, meridian)
         hour = hour.to_i
         return hour if meridian.nil?

spec/formats_spec.rb

@@ -226,6 +226,21 @@ describe ValidatesTimeliness::Formats do
     end
   end
   
+  describe "removing US formats" do
+    it "should validate a date as European format when US formats removed" do
+      time_array = formats.extract_date_time_values('01/02/2000', :date)
+      time_array.should == [2000, 1, 2,nil,nil,nil,nil]
+      formats.remove_us_formats
+      puts formats.datetime_formats.inspect
+      time_array = formats.extract_date_time_values('01/02/2000', :date)
+      time_array.should == [2000, 2, 1,nil,nil,nil,nil]
+    end
+    
+    after do
+      
+    end
+  end
+ 
   def validate(time_string, type)
     valid = false
     formats.send("#{type}_expressions").each do |(regexp, processor)|