Ruby post title to slug

问题

How should I convert a post title to a slug in Ruby?

The title can have any characters, but I only want the slug to allow [a-z0-9-_] (Should it allow any other characters?).

So basically:

downcase all letters
convert spaces to hyphens
delete extraneous characters

回答1:

slug = title.downcase.strip.gsub(' ', '-').gsub(/[^\w-]/, '')

downcase makes it lowercase. The strip makes sure there is no leading or trailing whitespace. The first gsub replaces spaces with hyphens. The second gsub removes all non-alpha non-dash non-underscore characters (note that this set is very close to \W but includes the dash as well, which is why it's spelled out here).

回答2:

Is this Rails? (works in Sinatra)

string.parameterize

That's it. For even more sophisticated slugging, see ActsAsUrl. It can do the following:

"rock & roll".to_url => "rock-and-roll"
"$12 worth of Ruby power".to_url => "12-dollars-worth-of-ruby-power"
"10% off if you act now".to_url => "10-percent-off-if-you-act-now"
"kick it en Français".to_url => "kick-it-en-francais"
"rock it Español style".to_url => "rock-it-espanol-style"
"tell your readers 你好".to_url => "tell-your-readers-ni-hao"

回答3:

to_slug is a great Rails plugin that handles pretty much everything, including funky characters, but its implementation is very simple. Chuck it onto String and you'll be sorted. Here's the source condensed down:

String.class_eval do
  def to_slug
    value = self.mb_chars.normalize(:kd).gsub(/[^\x00-\x7F]/n, '').to_s
    value.gsub!(/[']+/, '')
    value.gsub!(/\W+/, ' ')
    value.strip!
    value.downcase!
    value.gsub!(' ', '-')
    value
  end
end