validate date and time inputs

lib/date_time_attribute_validate.rb

@@ -0,0 +1,66 @@
+# workaround for https://github.com/einzige/date_time_attribute/issues/14
+require 'date_time_attribute'
+
+module DateTimeAttributeValidate
+  extend ActiveSupport::Concern
+  include DateTimeAttribute
+
+  module ClassMethods
+
+    def date_time_attribute(*attributes)
+      super
+
+      attributes.each do |attribute|
+
+        validate "#{attribute}_datetime_value_valid"
+
+        # allow resetting the field to nil
+        before_validation do
+          if self.instance_variable_get("@#{attribute}_is_set")
+            date = self.instance_variable_get("@#{attribute}_date_value")
+            time = self.instance_variable_get("@#{attribute}_time_value")
+            if date.blank? and time.blank?
+              self.send("#{attribute}=", nil)
+            end
+          end
+        end
+
+        # remember old date and time values
+        define_method("#{attribute}_date_value=") do |val|
+          self.instance_variable_set("@#{attribute}_is_set", true)
+          self.instance_variable_set("@#{attribute}_date_value", val)
+          self.send("#{attribute}_date=", val) rescue nil
+        end
+        define_method("#{attribute}_time_value=") do |val|
+          self.instance_variable_set("@#{attribute}_is_set", true)
+          self.instance_variable_set("@#{attribute}_time_value", val)
+          self.send("#{attribute}_time=", val) rescue nil
+        end
+
+        # fallback to field when values are not set
+        define_method("#{attribute}_date_value") do
+          self.instance_variable_get("@#{attribute}_date_value") || self.send("#{attribute}_date").try {|e| e.strftime('%Y-%m-%d')}
+        end
+        define_method("#{attribute}_time_value") do
+          self.instance_variable_get("@#{attribute}_time_value") || self.send("#{attribute}_time").try {|e| e.strftime('%H:%m')}
+        end
+
+        private
+
+        # validate date and time
+        define_method("#{attribute}_datetime_value_valid") do
+          date = self.instance_variable_get("@#{attribute}_date_value")
+          unless date.blank? or (Date.parse(date) rescue nil)
+            errors.add(attribute, "is not a valid date") # @todo I18n
+          end
+          time = self.instance_variable_get("@#{attribute}_time_value")
+          unless time.blank? or (Time.parse(time) rescue nil)
+            errors.add(attribute, "is not a valid time") # @todo I18n
+          end
+        end
+
+      end
+    end
+
+  end
+end