How to add errors to Rails model?

Question

I tried to add an exception in the before_save method in a rails model, but in the view, no error message exists.

Model:

before_save do     doing_some_stuff     begin       File.open('some_file', 'w+') do |file|         if file.write(file_content)           return true         else           return false         end       end     rescue => e       self.errors.add(:base, e.message)        return false     end 

View:

<%= @model.errors.any? %> 

This is always false.

How do I add error messages to the model?

EDIT:

The problem was, I had a redirect after the update_attribute function instead of rendering the action again. Thx for help.

Answer 1

You should be performing this on validation, not on before_save. By the time you get to the before_save callback, the record is assumed to be valid.

validate do   doing_some_stuff   begin     File.open(some_file, 'w+') do |file|       if !file.write(file_content)         self.errors.add(:base, "Unable to write #{some_file}")       end     end   rescue => e     self.errors.add(:base, e.message)   end end