Fix Style/AndOr offenses

From Ruby Style Guide:

> Do not use `and` and `or` in boolean context - and and or are control
flow operators and should be used as such. They have very low
precedence, and can be used as a short form of specifying flow sequences
like "evaluate expression 1, and only if it is not successful
(returned `nil`), evaluate expression 2". This is especially useful for
raising errors or early return without breaking the reading flow.

Also:

- Remove redundant use of self
- Use attribute reader instead of accessing instance variable

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/axlsx/workbook/worksheet/data_validation.rb b/lib/axlsx/workbook/worksheet/data_validation.rb
index eca90743..bc9bc527 100644
--- a/lib/axlsx/workbook/worksheet/data_validation.rb
+++ b/lib/axlsx/workbook/worksheet/data_validation.rb
@@ -243,8 +243,8 @@ module Axlsx
         str << key_value.first << '="' << Axlsx.booleanize(key_value.last).to_s << '"'
       end
       str << '>'
-      str << '<formula1>' << self.formula1 << '</formula1>' if @formula1 and valid_attributes.include?(:formula1)
-      str << '<formula2>' << self.formula2 << '</formula2>' if @formula2 and valid_attributes.include?(:formula2)
+      str << '<formula1>' << formula1 << '</formula1>' if formula1 && valid_attributes.include?(:formula1)
+      str << '<formula2>' << formula2 << '</formula2>' if formula2 && valid_attributes.include?(:formula2)
       str << '</dataValidation>'
     end