Sinatra pass anonymous block - ruby

Question

I am new to Sinatra and am trying to implement the following:
REST service with get method whose action block can be provided. Something like:
class C1
get '/something' do
<some action to be provided later>
end
post '/something' do
<some action to be provided later>
end
end
C1.new
C1.get_block = { "Hello from get" }
C1.post_block = { "Hello from post" }
Is it possible to do something like above? I am designing an intercepting service which can be used to perform different actions depending on conditions

Answer 1

The following should do the trick. I've added arrays so you can register multiple blocks that should be executed upon a GET/POST requests.
class C1
##get_blocks = []
##post_blocks = []
def register_get(block)
##get_blocks << block
end
def register_post(block)
##post_blocks << block
end
get '/something' do
##get_blocks.each do |block|
block.call(params)
end
end
post '/something' do
##post_blocks.each do |block|
block.call(params)
end
end
end
C1.new
C1.register_get { |params| "Hello from get" }
C1.register_post { |params| "Hello from post" }

Answer 2

I think #MartinKonecny answered the question using a very nice dynamic and effective approach...
...But please allow me to suggest a different approach, assuming that the code itself is static and that it is activated according to a set of conditions.
I know that using the Plezi framework you could alternate controllers for the same route, so that if one controller doesn't answer the request, the next one is tested.
I believe that Sinatra could be used in the same way, so that when the first route fails, the second route is attempted.
A short demonstration of the concept (not an actual app code), using the Plezi framework would look something like this:
require 'plezi'
listen
class C1
def index
"Controller 1 answers"
end
def hello
false
end
end
class C2
def show
"Controller 2 shows your request for: #{params[:id]}"
end
def hello
'Hello World!'
end
end
route '/(:id)', C1
route '/(:id)', C2
exit # exit the terminal to test this code.
This way, for the path localhost:3000/, the C1 class answers. But, the route for C1 fails the restful request for the path localhost:3000/1, so the route for C2 answers that request, attempting to show object with id==1.
This is easy to see when accessing the localhost:3000/hello route - the first route fails, and the second one is then attempted.
If you don't need to define the blocks dynamically, perhaps this approach - which I assume to be available also in Sinatra - will be more easy to code and maintain.
If this isn't available using Sinatra, you could probably imitate this approach using a "routing" class as a controller on your Sinatra app.
Another approach would be to specify the conditions in a case statement, calling different methods according to each situation.
class C1
get '/something' do
case
when true # condition
# do something
when true # condition
# do something
when true # condition
# do something
when true # condition
# do something
else
# do something
end
end
end