rosbridge_library.capability module

class rosbridge_library.capability.Capability(protocol: Protocol)

Bases: object

Handles the operation-specific logic of a rosbridge message.

May define one or more opcodes to handle, for example ‘publish’ or ‘call_service’

Each connected client receives its own capability instance, which are managed by the client’s own protocol instance.

Protocol.send() is available to send messages back to the client.

basic_type_check(msg: dict[str, Any], types_info: Sequence[tuple[bool, str, type | tuple[type, ...]]]) → None

Perform basic typechecking on fields in msg.

Parameters:

• msg – A message, deserialized into a dictionary

• types_info –

  A sequence of tuples (mandatory, fieldname, fieldtype) where

  • mandatory - boolean, is the field mandatory

  • fieldname - the name of the field in the message

  • fieldtypes - the expected python type of the field or tuple of types

Raises:

• MissingArgumentException – If a field is mandatory but not present in the message

• InvalidArgumentException – If a field is present but not of the type specified by fieldtype

finish() → None

Notify this capability that the client is finished.

Tells the capability that it’s time to free up resources.

handle_message(message: dict[str, Any]) → None

Handle an incoming message.

Called by the protocol after having already checked the message op code.

Parameters:

message – The incoming message, deserialized into a dictionary