def response
id = @a[0]
opts = @a[1]
callback = @r[-1]
if CPEE::Persistence::is_member?(id,opts,'callbacks',callback)
res = {}
res[:uuid] = CPEE::Persistence::extract_item(id,opts,"callback/#{callback}/uuid")
res[:type] = CPEE::Persistence::extract_item(id,opts,"callback/#{callback}/type")
res[:position] = CPEE::Persistence::extract_item(id,opts,"callback/#{callback}/position")
res[:label] = CPEE::Persistence::extract_item(id,opts,"callback/#{callback}/label")
if sub = CPEE::Persistence::extract_item(id,opts,"callback/#{callback}/subscription")
res[:subscription] = sub
end
Riddl::Parameter::Complex.new("callback","application/json",JSON.generate(res))
else
@status = 404
end
end