Route Constraints

TASK:

• constraint T&C policy routes according to its parameters.

EX:

• /en/us/legal/terms.f0a6f2aa-8e68-45ae-a875-84444ef1130f

constraints:

• languageCode – 2 alpha characters – EX: en/ fr/ sp
• country – 2 alpha characters – EX: us/ ca/ uk
• policy – 3 types – EX: Terms/ Privacy/ Electronic
• guid – standard – 32 hexadecimal digits – EX: 21EC2020-3AEA-1069-A2DD-08002B30309D

—————————————————————————————————————–
rspec:
note: the guid is located after the “.”, which works as a separator for formatted routes,
hence the :format=>guid instead of :guid => guid.

describe "GET policies" do
    it "should route to us privacy page" do
      { :get => '/en/us/legal/privacy.f0a6f2aa-8e68-45ae-a875-84444ef1130f'}.should
      route_to(:controller=>"pages", :action=>"privacy")
    end

    it "should route to ca terms page" do
      { :get => '/en/ca/legal/terms.f0a6f2aa-8e68-45ae-a875-84444ef1130f'}.should
      route_to(:controller=>"pages", :action=>"terms_ca")
    end

    it "should route to 404 page when given invalid policy parameter" do
      { :get => '/en/ca/legal/invalid.f0a6f2aa-8e68-45ae-a875-84444ef1130f'}.should
      route_to(:controller=> "errors", :action => "routing",
               :path=>"en/ca/legal/invalid",
               :format=> "f0a6f2aa-8e68-45ae-a875-84444ef1130f")
    end

    it "should route to 404 page when given invalid country parameter" do
      { :get => '/en/invalid/legal/terms.f0a6f2aa-8e68-45ae-a875-84444ef1130f'}.should
      route_to(:controller=> "errors", :action => "routing",
               :path=>"en/invalid/legal/terms",
               :format=> "f0a6f2aa-8e68-45ae-a875-84444ef1130f")
    end

    it "should route to 404 page when given invalid language parameter" do
      { :get => '/invalid/us/legal/privacy.f0a6f2aa-8e68-45ae-a875-84444ef1130f'}.should
      route_to(:controller=> "errors", :action => "routing",
               :path=>"invalid/ca/legal/privacy",
               :format=> "f0a6f2aa-8e68-45ae-a875-84444ef1130f")
    end

    it "should route to 404 page when given invalid guid" do
      { :get => '/en/us/legal/privacy.invalid'}.should
      route_to(:controller=> "errors", :action => "routing",
               :path=>"en/ca/legal/privacy",
               :format=> "invalid")
    end

  end

# routes.rb

constraints(PolicyConstraint) do
   get ':language/:country/legal/:policy.:guid' => "pages#policy_by_type",
        :constraints => {:language => /[a-zA-Z]{2}/, :country => /[a-zA-Z]{2}/,
        :guid=>/[\h]{8}-[\h]{4}-[\h]{4}-[\h]{4}-[\h]{12}/}

end

An example of policy_by_type method that is used for filtering two countries: CA and US.
# pages_controller.rb

  def policy_by_type
    if params[:country].upcase == "CA"
      case params[:policy]
        when "terms"
          redirect_to terms_ca_url
        when "privacy"
          redirect_to privacy_ca_url
        when "electronic_communication"
          redirect_to electronic_communication_ca_url
        else
          render_404
      end
    else
      case params[:policy]
        when "terms"
          redirect_to terms_url
        when "privacy"
          redirect_to privacy_url
        when "electronic_communication"
          redirect_to electronic_communication_url
        else
          render_404
      end
    end
  end

now for constraining policy segment:
# constraints/policy_constraint.rb

class PolicyConstraint
   def self.matches?(request)
     policy_types = ['terms', 'privacy', 'electronic']
     policy_types.include?(request.parameters[:policy])
   end
end

and viola the route is now “constrained” (:

more info: http://guides.rubyonrails.org/routing.html