roda-message_bus integrates message_bus into the roda web toolkit, allowing you to call message_bus only for specific paths, after any access control checks have been made.

gem install roda-message_bus

Source code is available on GitHub at github.com/jeremyevans/roda-message_bus

roda-message_bus is a roda plugin, so you need to load it into your roda application similar to other plugins:

class App < Roda
  plugin :message_bus
end

In your routing block, you can use r.message_bus to pass the routing to message bus. Generally you’ll want to do this after making any access control checks:

App.route do |r|
  r.on "room/:id" do |room_id|
    room_id = room_id.to_i
    raise unless current_user.has_access?(room_id)

    # Allows "/room/#{room_id}" channel by default
    r.message_bus

    view(:room)
  end
end

Routing will halt in r.message_bus if the request is a message_bus request. If the request is not a message_bus request, execution will continue without yielding.

If you want to, you can force a specific message_bus channel (or channels by passing an array) when calling r.message_bus:

# Override channel to use (can also provide array of channels)
r.message_bus("/room/#{room_id}/enters")

The default channel if you don’t pass an argument to r.message_bus is the already routed path, including the SCRIPT_NAME if present. So if you call r.message_bus at the top of the routing tree, you’ll probably want to specify the channel unless you want to use the empty channel.

If you pass a block to r.message_bus, it will be yielded to only if this is a message_bus request.

r.message_bus do
  # executed right before passing control to message_bus
end

For roda-message_bus to work, in your MessageBus javascript code, you must set the baseUrl to match the routing tree branch where you are calling r.message_bus:

<script type="text/javascript" src="/message-bus.js"></script>
<script type="text/javascript">
  MessageBus.baseUrl = "<%= request.path_info %>/";
</script>

MIT

Jeremy Evans <code@jeremyevans.net>