Question

I have an ActiveRecord model, Foo, which has a name field. I’d like users to be able to search by name, but I’d like the search to ignore case and any accents. Thus, I’m also storing a canonical_name field against which to search:

class Foo   validates_presence_of :name    before_validate :set_canonical_name    private    def set_canonical_name     self.canonical_name ||= canonicalize(self.name) if self.name   end    def canonicalize(x)     x.downcase.  # something here   end end 

I need to fill in the ‘something here’ to replace the accented characters. Is there anything better than

x.downcase.gsub(/[àáâãäå]/,'a').gsub(/æ/,'ae').gsub(/ç/, 'c').gsub(/[èéêë]/,'e').... 

And, for that matter, since I’m not on Ruby 1.9, I can’t put those Unicode literals in my code. The actual regular expressions will look much uglier.

Answer 1

Rails has already a builtin for normalizing, you just have to use this to normalize your string to form KD and then remove the other chars (i.e. accent marks) like this:

>> 'àáâãäå'.mb_chars.normalize(:kd).gsub(/[^\x00-\x7F]/n,'').downcase.to_s => 'aaaaaa'