Module message

Get the message class. NOTE: this function maintains a local cache of results to improve performance.

Parameters:

• message_type (str) - type name of message
• reload_on_error - (optional). Attempt to reload the Python module if unable to load message the first time. Defaults to False. This is necessary if messages are built after the first load.

Returns: Message class

Message class for message/service type

Raises:

• ValueError - if message_type is invalidly specified

Get the service class. NOTE: this function maintains a local cache of results to improve performance.

Parameters:

• service_type (str) - type name of service
• reload_on_error - (optional). Attempt to reload the Python module if unable to load message the first time. Defaults to False. This is necessary if messages are built after the first load.

Returns: Service class

Service class for service type

Raises:

• Exception - if service_type is invalidly specified

Convert value to string representation

Parameters:

• val (Value) - to convert to string representation. Most likely a Message.
• indent (str) - indentation. If indent is set, then the return value will have a leading
• time_offset (Time) - if not None, time fields will be displayed as deltas from time_offset
• current_time (Time) - currently not used. Only provided for API compatibility. current_time passes in the current time with respect to the message.
• field_filter (fn(Message)->iter(str)) - filter the fields that are strified for Messages.

Returns: str

string (YAML) representation of message

Dynamic type checker that maps ROS .msg types to python types and verifies the python value. check_type() is not designed to be fast and is targeted at error diagnosis. This type checker is not designed to run fast and is meant only for error diagnosis.

Parameters:

• field_name (str) - ROS .msg field name
• field_type (str) - ROS .msg field type
• field_val (Any) - field value

Raises:

• SerializationError - if typecheck fails

Get string representation of msg arguments

Parameters:

• msg (Message) - msg message to fill
• prefix (str) - field name prefix (for verbose printing)

Returns: str

printable representation of msg args

Populate message with specified args. Args are assumed to be a list of arguments from a command-line YAML parser. See http://www.ros.org/wiki/ROS/YAMLCommandLine for specification on how messages are filled.

fill_message_args also takes in an optional 'keys' dictionary which contain substitute values for message and time types. These values must be of the correct instance type, i.e. a Message, Time, or Duration. In a string key is encountered with these types, the value from the keys dictionary will be used instead. This is mainly used to provide values for the 'now' timestamp.

Parameters:

• msg (Message) - message to fill
• msg_args ([args]) - list of arguments to set fields to, or If None, msg_args will be made an empty list.
• keys (dict) - keys to use as substitute values for messages and timestamps.

Raises:

• ROSMessageException - if not enough/too many message arguments to fill message