Question

I developed a Rack application based on Sinatra::Base. Now I would like to use many instances of it, each with a slightly different configuration, in a single Rack application.

My rackup should look like

use Rack::Lint

map '/mel' do
    run Site.new('/home/mel/site').app
end

map '/pub' do
    run Site.new('/pub').app
end

The Site class collects various parameters (in this example only the root dir) and does some preparatory work. The #app method should return a Server object that holds a reference to the served Site instance.

This is an example of the Site and Server code:

class Site
    def initialize(root_dir)
        @root_dir = root_dir
        # ... set up things ...
    end

    def app
        # This is where a new Server Rack application should be created
        return Server.new { |server| server.set :site, self }
    end
end

class Server < Sinatra::Base
    before do
        @content = settings.site.all_files
    end

    get /(.*)/ do |url_path|
        # do things...
    end
end

The problem with this code is that the #app method does not return a valid Rack application.

What should I do in #app to return a new, configured Server Rack application?

Answer 1

This is a way to make it work suggested by “carloslopes” on #sinatra.

The Site#app method becomes

class Site
    def app
        # This is where a new Server object should be created
        return Server.new(self)
    end
end

and the Server objects get their parameters via instance variables:

class Server < Sinatra::Base
    def initialize(site)
        super()
        @site = site
    end

    before do
        @content = @site.all_files
    end

    get /(.*)/ do |url_path|
        # do things...
    end
end

Edit: made community wiki so that other can make the solution even better and share the credit.