Can you put a variable in a regexp?

Question

I'm trying to validate wether a Model.category equals any existing Category name

unless Category.exists?(:name => self.category.downcase)

I had to put downcase in this to ensure all of them were downcased so they could match up as strings. But its a big server hit to update the attribute before_save, and I was thinking of just matching them via regexp. Something like this

unless Category.exists?(:name => /#{self.category}/ }

Is there something like that possible? Or is there a better way to do this?

Answer 1

Yep, you can use variable interpolation in a regex.

>> s = "thing"
=> "thing"
>> r = /#{s}/
=> /thing/