Rails validates if present

validates_format_of :avatar_file_name, 
 :with=>/\.(jpeg|jpg|png|gif)$/i, 
 :message=> I18n.t("..."), 
 :on => :update,
 :if => lambda{ |object| object.avatar_file_name.present? }

Source: stackoverflow.com

Similar codes

0 vote249 views1 answer
Copy to clipboard in ruby in windows
Ruby
0 vote209 views1 answer
Font awesome rails
Ruby
0 vote223 views1 answer
Rails include module
Ruby
0 vote218 views1 answer
Ruby sinatra enable sessions
Ruby
2 votes208 views1 answer
Form feild rails helper
Ruby
0 vote206 views1 answer
How to install webpck on ubuntu globally
Ruby
0 vote188 views1 answer
Ruby random number between
Ruby
0 vote217 views5 answers
Roblox.com redeem robux codes
Ruby
2 votes218 views4 answers
Rails run rake task
Ruby
0 vote235 views3 answers
Rails resources
Ruby