Sinatra routes regular expression alphanumeric

Question

#get "/blog/:title-:slug" do
#  erb :"/blog/#{params[:slug]}.html
#end

both :title and slug can be alphanumeric.

I am trying to make the url dynamic with regular expression.

get '/blog/*-*' do
    erb :"/blog/#{params['splat'][1]}.html"
end

I came up with the version above which uses a wildcard and that works but I am hoping to make the route more specific. I am currently struggling with what I have below after consulting the ruby regexp documentation.

# get '/blog\/[[:alnum:]]/-/[[:alnum:]]/' do
#   puts params['alnum']
#   erb :"/blog/#{params['alnum']}.html"
# end

Answer 1

Sinatra accepts regexp values as the parameter to route methods (get, post etc.), so the route can be rewritten as:

get %r{/blog/(\w+)-(\w+)} do
  ...
end

This will match all the routes that have alphabets or numbers. However, the captured values won't be available in the params object. To achieve that, you'd need to use the named captures syntax:

get %r{/blog/(?<title>\w+)-(?<slug>\w+)} do
  puts params[:title]
  puts params[:slug]
end

you can also use the unicode-aware [[:alnum:]] regexp matcher:

get %r{/blog/(?<title>[[:alnum:]]+)-(?<slug>[[:alnum:]]+)} do
  puts params[:title]
  puts params[:slug]
end